**Acute Lymphoblastic Leukemia (ALL) Philadelphia Positive (Ph1) (Incidence Classifications, Prognostic Factor in ALL Principles of ALL Therapy)**

Alicia Enrico and Jorge Milone

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/55095

## **1. Introduction**

[64] Garmey EG, Liu Q, Sklar CA, Meacham LR, Mertens AC, Stovall MA, Yasui Y, Robi‐ son LL, Oeffinger KC. Longitudinal changes in obesity and body mass index among adult survivors of childhood acute lymphoblastic leukemia: a report from the Child‐

hood Cancer Survivor Study. Journal of clinical oncology 2008;26(28) 4639-45.

1303-12.

nal of clinical nutrition 2006;83(1):70-4.

296 Clinical Epidemiology of Acute Lymphoblastic Leukemia - From the Molecules to the Clinic

[65] Gurney JG, Ness KK, Sibley SD, O'Leary M, Dengel DR, Lee JM, Youngren NM, Glasser SP, Baker KS. Metabolic syndrome and growth hormone deficiency in adult survivors of childhood acute lymphoblastic leukemia. Cancer. 2006 Sep 15;107(6):

[66] Murphy AJ, Wells JC, Williams JE, Fewtrell MS, Davies PS, Webb DK. Body composi‐ tion in children in remission from acute lymphoblastic leukemia. The American jour‐

> ALL is a malignancy of lymphoid cells occurring at any age. Almost 5000 cases are diagnosed annually in the USA. Cell-B subtypes account for 85–90% of cases in children and 75–80% of cases in adults; T-lineage ALL accounts for a small proportion of cases. It has a bimodal incidence occurring at 2–4 years of age followed by a gradual increase after the age of 50.

> In the last years much progress has been made in understanding the biology of acute lymphoblastic leukemia which is now recognized as an expanding group of heterogene‐ ous entities. Recognition of distinct gene expression patterns may identify patient sub‐ group with unique response to therapy and prognosis. Accurate definition of prognostic subgroups based on cytogenetic molecular marker has allowed institution of risk orient‐ ed therapies. [2] The Philadelphia (Ph1+) chromosome was first described in 1960 in a patient with chronic myeloid leukemia (CML). This is the product of the fusion of chromosomes 9 and 22, t (9;22), which results in a BCR-ABL hybrid gene. [2]

> The incidence is approximately 20-30 % of adult patients with ALL who present the Philadel‐ phia (Ph) Chromosome. Whereas Ph+ ALL is rare in children, comprising less than 5% of acute lymphoblastic leukemia, its incidence increases to approximately 40% in adults 40 years of age, with a 10% increment for every further decade of life with no sex difference. The majority of patients are diagnosed with de novo Ph+ ALL, although occasional cases of secondary Ph1+, ALL have been reported following chemotherapy or radiation therapy. [3, 4]. There are no known risk factors for Ph+ ALL. The associations with environmental socioeconomic infections and genetic events are being studied extensively in ALL. Few causal links have been estab‐ lished and the etiology of ALL remains obscure in most cases. The strongest associations to

© 2013 Enrico and Milone; licensee InTech. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2013 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

date exist with genetic factors and the role of Epstein Barr virus (EBV) and human immuno‐ deficiency virus (HIV) in patients with mature B cell ALL [2].

distinction is usually of no clinical significance. However, as newly diagnosed LBC-CML

Acute Lymphoblastic Leukemia (ALL) Philadelphia Positive…

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299

**3. Treatment of Ph 1+ ALL: The result with Imatinib and chemotherapy**

Chemotherapy alone for adult with ALL Ph1+ is poor, with less than 10% probability. Long term survival. The development of tirosi kinase inhibitor, imatinib and its use with chemo‐ theray for the induction obtained complete remission in ranged from 60-70%, moderately lower than 70-90 % achieved in Ph1+ negative ALL. The median CR duration was considerably inferior, however ranging from 9-16 month in patients treated only with chemotherapy with almost no long term survivor. Because of the poor outcome with chemotherapy, the allogeneic stem cell transplantation (SCT) is considered to be the treatment of choice in adult Ph+ ALL. [9] Imatinib Mesylate (STI571 GlivecR) (IM) was the first Tirosin Kinase inhibitor for CML treatment and now is the gold standard for the treatment of de novo CML in chronic phase. The BCR/ABL fusion gene encodes the chimeric BCR/ABL oncoprotein which has constitu‐ tively active tyrosine kinase activity. This results in dysregulated activity of additional signal transduction pathways located downstream of BCR/ABL. The strong pathophysiological similarity between Ph+ ALL and CML provided the rationale for exploring the clinical efficacy

Druker et al. in one of the first evidence of clinical activity from a phase I study in 2001, in relapsed or refractory patients with Ph+ ALL which showed a significant number of hemato‐ logical responses (70%) although only 20 % of the patients achieved a complete remission (CR). Later in 2002 these results were confirmed in phase II studies in which imatinib at daily doses of 400 mg to 600 mg induced a CR in 19% of the patients. These responses were not sustained however, and the estimated median survival in these studies was only 4.9 months. As a consequence, subsequent studies focused on the use of imatinib during front line therapy of Ph+ ALL, both as a single agent therapy and in combination with various chemotherapy regimens. A major goal of studies performed in younger patients was to increase the CR rate and improve the quality of response prior to hematopoietic stem cell transplantation (HSTC) in patients with a suitable donor. [12,13]. Several strategies have been evaluated to optimize the combination of imatinib and chemotherapy. Initial studies were based on schedules alternating imatinib and chemotherapy cycles followed by clinical trials that investigated schedules in which imatinib and chemotherapy were given concomitantly. The question of whether minimization of chemotherapy related toxicity by combining imatinib with less intensive chemotherapy or administering it alone yielded equivalent or superior results was

The current standard approach for patients in the combination of a chemotherapy protocol employing four to five cytotoxic agents typically used for ALL with imatinib at a daily dose of 400 mg to 800 mg (Table 1). Complete remission rates in these studies consistently exceeded 90%, the profile and incidence of severe toxicity were not different from those associated with the historic chemotherapy alone regimens. The overall survival (OS) in the different studies

without a prior history of CML is generally treated in the same way as Ph+ ALL. [8]

of IM. [10].

also addressed. [11]

## **2. Diagnosis**

The characteristic findings of Ph1+ ALL is a reciprocal translocation t(9,22) (q34q11) that fuses the BCR gene from chromosome 22 to the ABL gene from chromosome 9. By standard cytogenetic analysis this becomes apparent as a shortened chromosome 22 referred to as the Philadelphia chromosome, which can also be visualized by fluorescent in situ hybridization (FISH) analysis. At the molecular level, the bcr/abl fusion transcript can be detected by RT-PCR. The location of the breakpoint within the BCR gene results in either the p190BCR/ABL protein observed in Ph+ ALL (66.3% of the cases) or the p210 BCR/ABL protein common to patients with Ph+ CML which is present in ALL Ph+ (31,2%) The remaining cases are associated either with both transcript type or with atypical transcripts. [4]

Other additional chromosome aberrations were present in up to 79% of the cases in a large study of 209 patients (Moorman et al). Yanada et al. study involving 77 Ph+ ALL pa‐ tients, additional aberrations with a frequency of greater than 10% included a second Ph chromosome (+der(22) t (9,22)) abnormalities involving the short arm of chromosome 9, monosomy 7, and trisomy 8. The presence of additional aberrations was associated with significantly shorter relapse free survival (RFS) and higher relapse rate. This was particular‐ ly pronounced for the +der (22)t(9,22) and abnormalities involving the short arm chromo‐ some 9. In reference to this, standard karyotyping is mandatory to establish the initial diagnosis while FISH analysis may be used as a confirmatory technique. The major role of PCR analysis at diagnosis is determination of the type of fusion transcript, which be‐ comes relevant during follow up studies of MDR. Using only PCR to establish the diagnosis is not acceptable, even more so as occasional patients harbor an aberrant fusion tran‐ script that is not detected by standard primer combination [5,6.]

The white blood cell count is variable at diagnosis, hyperleukocytosis and/or splenomegaly may be present. Ph+ ALL is a B-precursor ALL which typically expresses the CD19 and CD10 antigens, and the CD34 antigen is expressed in 89% of cases. The most frequent immunologic subtypes are common ALL (78.2%) and pre-B ALL (19.9%), whereas only 1.9% of patients display the pro – B immunophenotype. Except for few case reports, the chromosome is not found in T linage ALL. Myeloid markers are frequently expressed, most notably the CD13 antigen (20%) and CD33 antigen (15%). CNS leukemia is infrequent (5%) at initial presentation, but there is an increased risk of developing meningeal leukemia during the course of treatment when compared with other B linage ALL. [7]

The main differential diagnosis at the begime,of the disease is chronic myelogenous leukemia (CML) lymphoblastic blast crisis (LBC). In the absence of a history of CML, myeloid hyper‐ plasia, bone marrow basophilia, eosinophilia or excessive splenomegaly are suggestive of LBC-CML. While identification of the e1a2 fusion product (p190 BCR-ABL) essentially rules out CML, the major BCR fusion transcript (p210 BCR-ABL) is found in both Ph+ ALL and LBC-CML. This distinction is usually of no clinical significance. However, as newly diagnosed LBC-CML without a prior history of CML is generally treated in the same way as Ph+ ALL. [8]

date exist with genetic factors and the role of Epstein Barr virus (EBV) and human immuno‐

The characteristic findings of Ph1+ ALL is a reciprocal translocation t(9,22) (q34q11) that fuses the BCR gene from chromosome 22 to the ABL gene from chromosome 9. By standard cytogenetic analysis this becomes apparent as a shortened chromosome 22 referred to as the Philadelphia chromosome, which can also be visualized by fluorescent in situ hybridization (FISH) analysis. At the molecular level, the bcr/abl fusion transcript can be detected by RT-PCR. The location of the breakpoint within the BCR gene results in either the p190BCR/ABL protein observed in Ph+ ALL (66.3% of the cases) or the p210 BCR/ABL protein common to patients with Ph+ CML which is present in ALL Ph+ (31,2%) The remaining cases are associated either with

Other additional chromosome aberrations were present in up to 79% of the cases in a large study of 209 patients (Moorman et al). Yanada et al. study involving 77 Ph+ ALL pa‐ tients, additional aberrations with a frequency of greater than 10% included a second Ph chromosome (+der(22) t (9,22)) abnormalities involving the short arm of chromosome 9, monosomy 7, and trisomy 8. The presence of additional aberrations was associated with significantly shorter relapse free survival (RFS) and higher relapse rate. This was particular‐ ly pronounced for the +der (22)t(9,22) and abnormalities involving the short arm chromo‐ some 9. In reference to this, standard karyotyping is mandatory to establish the initial diagnosis while FISH analysis may be used as a confirmatory technique. The major role of PCR analysis at diagnosis is determination of the type of fusion transcript, which be‐ comes relevant during follow up studies of MDR. Using only PCR to establish the diagnosis is not acceptable, even more so as occasional patients harbor an aberrant fusion tran‐

The white blood cell count is variable at diagnosis, hyperleukocytosis and/or splenomegaly may be present. Ph+ ALL is a B-precursor ALL which typically expresses the CD19 and CD10 antigens, and the CD34 antigen is expressed in 89% of cases. The most frequent immunologic subtypes are common ALL (78.2%) and pre-B ALL (19.9%), whereas only 1.9% of patients display the pro – B immunophenotype. Except for few case reports, the chromosome is not found in T linage ALL. Myeloid markers are frequently expressed, most notably the CD13 antigen (20%) and CD33 antigen (15%). CNS leukemia is infrequent (5%) at initial presentation, but there is an increased risk of developing meningeal leukemia during the course of treatment

The main differential diagnosis at the begime,of the disease is chronic myelogenous leukemia (CML) lymphoblastic blast crisis (LBC). In the absence of a history of CML, myeloid hyper‐ plasia, bone marrow basophilia, eosinophilia or excessive splenomegaly are suggestive of LBC-CML. While identification of the e1a2 fusion product (p190 BCR-ABL) essentially rules out CML, the major BCR fusion transcript (p210 BCR-ABL) is found in both Ph+ ALL and LBC-CML. This

deficiency virus (HIV) in patients with mature B cell ALL [2].

298 Clinical Epidemiology of Acute Lymphoblastic Leukemia - From the Molecules to the Clinic

both transcript type or with atypical transcripts. [4]

script that is not detected by standard primer combination [5,6.]

when compared with other B linage ALL. [7]

**2. Diagnosis**

## **3. Treatment of Ph 1+ ALL: The result with Imatinib and chemotherapy**

Chemotherapy alone for adult with ALL Ph1+ is poor, with less than 10% probability. Long term survival. The development of tirosi kinase inhibitor, imatinib and its use with chemo‐ theray for the induction obtained complete remission in ranged from 60-70%, moderately lower than 70-90 % achieved in Ph1+ negative ALL. The median CR duration was considerably inferior, however ranging from 9-16 month in patients treated only with chemotherapy with almost no long term survivor. Because of the poor outcome with chemotherapy, the allogeneic stem cell transplantation (SCT) is considered to be the treatment of choice in adult Ph+ ALL. [9]

Imatinib Mesylate (STI571 GlivecR) (IM) was the first Tirosin Kinase inhibitor for CML treatment and now is the gold standard for the treatment of de novo CML in chronic phase. The BCR/ABL fusion gene encodes the chimeric BCR/ABL oncoprotein which has constitu‐ tively active tyrosine kinase activity. This results in dysregulated activity of additional signal transduction pathways located downstream of BCR/ABL. The strong pathophysiological similarity between Ph+ ALL and CML provided the rationale for exploring the clinical efficacy of IM. [10].

Druker et al. in one of the first evidence of clinical activity from a phase I study in 2001, in relapsed or refractory patients with Ph+ ALL which showed a significant number of hemato‐ logical responses (70%) although only 20 % of the patients achieved a complete remission (CR). Later in 2002 these results were confirmed in phase II studies in which imatinib at daily doses of 400 mg to 600 mg induced a CR in 19% of the patients. These responses were not sustained however, and the estimated median survival in these studies was only 4.9 months. As a consequence, subsequent studies focused on the use of imatinib during front line therapy of Ph+ ALL, both as a single agent therapy and in combination with various chemotherapy regimens. A major goal of studies performed in younger patients was to increase the CR rate and improve the quality of response prior to hematopoietic stem cell transplantation (HSTC) in patients with a suitable donor. [12,13]. Several strategies have been evaluated to optimize the combination of imatinib and chemotherapy. Initial studies were based on schedules alternating imatinib and chemotherapy cycles followed by clinical trials that investigated schedules in which imatinib and chemotherapy were given concomitantly. The question of whether minimization of chemotherapy related toxicity by combining imatinib with less intensive chemotherapy or administering it alone yielded equivalent or superior results was also addressed. [11]

The current standard approach for patients in the combination of a chemotherapy protocol employing four to five cytotoxic agents typically used for ALL with imatinib at a daily dose of 400 mg to 800 mg (Table 1). Complete remission rates in these studies consistently exceeded 90%, the profile and incidence of severe toxicity were not different from those associated with the historic chemotherapy alone regimens. The overall survival (OS) in the different studies ranged from 36 to 76 %, although follow up is short (1-3 years) while the superiority of adding imatinib to conventional chemotherapy was strongly suggested by historical comparisons between the outcome of the patients using similar chemotherapeutic schedules with or without imatinib the impact of imatinib based regimen on long-term outcome is difficult to assess due to the higher rate of patients undergoing SCT in CR1, which became possible due to a lower incidence of early relapses. [10]

Yanada et al. have likewise reported results in complete remission (CR) in 77 patient (96.2%), as well as polymerase chain reaction negativity of bone marrow in 71,3 % with the use a multidrug protocol plus imatinib. The authors described that the profile and incidence of severe toxicity were not different from those associated with our historic chemotherapy-alone regimen. Relapse occurred in 20 patient after median CR duration of 5,2 months. 49 patients underwent the allogeneic hematopoietic stem cell transplantation (HSCT), 39 of whom underwent transplantation during their first CR. The 1 year-event-free and overall survival (OS) rates were estimated to be 60.0% and 76.1%, respectively, which were significantly better than ourfortheir historic controls treated with chemotherapy alone. The probability of OS for this group of patients described by the author at 1 year was 73.3 % for those who underwent

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301

Lee K-H et al. evaluated 20 patients with Ph+ ALL who were administered with induction chemotherapy daunorrubicin, vincristine prednisolone and L asparaginase along with imatinib 600 mg /day during remission induction and 400 mg /day during consolidation courses. 19 patients achieved complete remission (CR). In this trials, 15 underwent allogeneic hematopoietic cell transplantation (HCT) during first CR. After median follow up period of 799 days, 6 patients experienced recurrence. Eight died. Median CR duration was 821 days and median patient survival was 894 days. In the study the results were significantly longer by 2.9 and 2.3 fold respectively when compared to those of 18 historical patient treatments

Wassmann et al. enrolled 92 patients with newly diagnosed Ph+ ALL in a prospective multi‐ center study to investigate sequentially 2 treatment schedules with imatinib administrated concurrent to or alternating with a uniform induction and consolidation regimen. Coadmi‐ nistration of imatinib and induction cycle2 (INDII) resulted in a CR rate of 95 % and polymerase chain reaction (PCR) negativity for BCR/ABL in 52 % of the patients compared with 19% in patients in the alternating treatment cohort. Remarkably, patients with and without a CR after induction cycle 1 (INDI) had similar hematologic and molecular responses after concurrent imatinib and INDII. 7 % of the patients underwent allogeneic stem cell transplantation (SCT), in first CR (CR1) both schedules of imatinib had acceptable toxicity and facilitated SCT in CR1 in the majority of patients but concurrent administration of imatinib and chemotherapy had

Labarthe et al. in 2007 published the results of 45 patients with Ph+ ALL treated in the Group for Research on Adult Acute Lymphoblastic Leukemia (GRAAPH) 2003 study, where imatinib was started with HAM (mitoxantrone with intermediate-dose cytarabine) as consolidation therapy in good early responders (corticosensitive and chemosensitive ALL) or earlier during the induction course in combination with dexamethasone and vincristine in poor early responders (corticoresistant and/or chemoresistant ALL). Imati‐ nib was then continuously administered until stem cell transplantation (SCT). Overall, complete remission (CR) and *BCR-ABL* real-time quantitative polymerase chain reaction (RQ-PCR) negativity rates were 96% and 29%, respectively. All of the 22 CR patients (100%) with a donor received allogeneic SCT in first CR. At 18 months, the estimated cumulative incidence of relapse, disease-free survival, and overall survival were 30%, 51%, and 65%,

allogeneic HSCT and 84.8% for those who did not. [15]

greater antileukemic efficacy for this group. [17]

with same regimen of combination chemotherapy without imatinib. [16]


*C= concurrent; A= alternating; NR= not reported; NA= not applicable; JALSG = Japan Adult Leukemia Study Group; GMALL= German Multi-Centre Acute Lymphoblastic Leukemia; hyper-CVAD= fractionated cyclophosphamide, vincristine, doxorubicine, dexamethasone; GRAAPH= Group for Research on Adult Acute Lymphoblastic Leukemia; GIMEMA= Gruppo Italiano Malattie Ematologiche dell´Adulto; GRAALL=Group for Research in Adult Acute Lymphoblastic Leukemia; Pred= prednisone* 

C= concurrent; A= alternating; NR= not reported; NA= not applicable; JALSG = Japan Adult Leukemia Study Group; GMALL= German Multi‐Centre Acute; Lymphoblastic Leukemia; hyper‐CVAD= fractionated cyclophosphamide, vincristine, doxorubicine, dexamethasone; GRAAPH= Group for Research on Adult Acute Lymphoblastic Leukemia; GIMEMA= Gruppo Italiano Malattie Ematologiche dell´Adulto; GRAALL=Group for Research in Adult Acute Lympho‐ blastic Leukemia; Pred= prednisone

**Table 1.** Studies combining imatinib with chemotherapy for de novo Philadelphia chromosome positive (Ph+) ALL [10]

## **4. Approach in young patients**

#### **4.1. Imatinib in combination with chemotherapy in younger patients**

The current standard approach for young patients is the combination of chemotherapy protocol employing four to five cytotoxic agent typically used for ALL with imatinib at a daily dose of 400 to 600 mg. Such an approach was pioneered by the MD Anderson Group. They combined sequential imatinib at 400 mg with 8 alternate hyper-CVAD and HD-MTX/AraC cycles (fractionated Cyclophosphamide, Vincristine, Doxorubicin and Dexamethasone alternating with cycles of high dose Methotrexate and Cytarabine) followed by imatinib maintenance at 600 mg/d. In this trial the CR rate was 93% with about 2 years of DFS rate of 75%. The molecular remission rate or negativity for bcr/abl transcript by RT-PCR and nested PCR approach 60%. [14]

Yanada et al. have likewise reported results in complete remission (CR) in 77 patient (96.2%), as well as polymerase chain reaction negativity of bone marrow in 71,3 % with the use a multidrug protocol plus imatinib. The authors described that the profile and incidence of severe toxicity were not different from those associated with our historic chemotherapy-alone regimen. Relapse occurred in 20 patient after median CR duration of 5,2 months. 49 patients underwent the allogeneic hematopoietic stem cell transplantation (HSCT), 39 of whom underwent transplantation during their first CR. The 1 year-event-free and overall survival (OS) rates were estimated to be 60.0% and 76.1%, respectively, which were significantly better than ourfortheir historic controls treated with chemotherapy alone. The probability of OS for this group of patients described by the author at 1 year was 73.3 % for those who underwent allogeneic HSCT and 84.8% for those who did not. [15]

ranged from 36 to 76 %, although follow up is short (1-3 years) while the superiority of adding imatinib to conventional chemotherapy was strongly suggested by historical comparisons between the outcome of the patients using similar chemotherapeutic schedules with or without imatinib the impact of imatinib based regimen on long-term outcome is difficult to assess due to the higher rate of patients undergoing SCT in CR1, which became possible due to a lower

> **Consolidation (mg/d)**

> > A (400/600) C (600)

> > > C (600) C (600)

**Thomas el al** Hyper-CVAD C (400) C (400) C (400) 39 92 14 83(3) 55 (3) **Yanada el al** JALSG ALL202 C (600) A (600) C (600) 80 96 26 60 (1)

**de Labarthe el al** GRAAPH-2003 None C (600) NR 45 96 19 51 (1.5) 65 (1.5)

*C= concurrent; A= alternating; NR= not reported; NA= not applicable; JALSG = Japan Adult Leukemia Study Group; GMALL= German Multi-Centre Acute Lymphoblastic Leukemia; hyper-CVAD= fractionated cyclophosphamide, vincristine, doxorubicine, dexamethasone; GRAAPH= Group for Research on Adult Acute Lymphoblastic Leukemia; GIMEMA= Gruppo Italiano Malattie Ematologiche dell´Adulto; GRAALL=Group for Research in Adult Acute* 

C= concurrent; A= alternating; NR= not reported; NA= not applicable; JALSG = Japan Adult Leukemia Study Group; GMALL= German Multi‐Centre Acute; Lymphoblastic Leukemia; hyper‐CVAD= fractionated cyclophosphamide, vincristine, doxorubicine, dexamethasone; GRAAPH= Group for Research on Adult Acute Lymphoblastic Leukemia; GIMEMA= Gruppo Italiano Malattie Ematologiche dell´Adulto; GRAALL=Group for Research in Adult Acute Lympho‐

**Table 1.** Studies combining imatinib with chemotherapy for de novo Philadelphia chromosome positive (Ph+) ALL [10]

The current standard approach for young patients is the combination of chemotherapy protocol employing four to five cytotoxic agent typically used for ALL with imatinib at a daily dose of 400 to 600 mg. Such an approach was pioneered by the MD Anderson Group. They combined sequential imatinib at 400 mg with 8 alternate hyper-CVAD and HD-MTX/AraC cycles (fractionated Cyclophosphamide, Vincristine, Doxorubicin and Dexamethasone alternating with cycles of high dose Methotrexate and Cytarabine) followed by imatinib maintenance at 600 mg/d. In this trial the CR rate was 93% with about 2 years of DFS rate of 75%. The molecular remission rate or negativity for bcr/abl transcript by RT-PCR and nested

**4.1. Imatinib in combination with chemotherapy in younger patients**

 **Imatinib dosing Results (%)**

47 45

28 27

**(mg/d) No CR Relapse DFS** 

NA NA

> 96 50

NR NR

> 41 54

**(at y)**

51 (2)

52 (2) 61 (2)

29 (1.5) 57 (1.5)

**Survival (at y)**

> 76 (1) 58 (2)

> 36 (2) 43 (2)

35 (1.5) 41 (1.5)

**Mantenance** 

Li nker C (600) C (400) C (400) 20 95 32 62 (2) 59 (2)

NR NR

C (600) C (600)

incidence of early relapses. [10]

**Chemotherapy regimen**

Modified from

GMALL Alternating Concurrent

GMALL Chemotherapy Imatinib

*Lymphoblastic Leukemia; Pred= prednisone* 

blastic Leukemia; Pred= prednisone

PCR approach 60%. [14]

**4. Approach in young patients**

**Induction (mg/d)**

300 Clinical Epidemiology of Acute Lymphoblastic Leukemia - From the Molecules to the Clinic

None None

None Only (600)

**Subtype**

*Adults*

**Lee et al**

**Wassmann et al**

**Ottmann et el al**

Lee K-H et al. evaluated 20 patients with Ph+ ALL who were administered with induction chemotherapy daunorrubicin, vincristine prednisolone and L asparaginase along with imatinib 600 mg /day during remission induction and 400 mg /day during consolidation courses. 19 patients achieved complete remission (CR). In this trials, 15 underwent allogeneic hematopoietic cell transplantation (HCT) during first CR. After median follow up period of 799 days, 6 patients experienced recurrence. Eight died. Median CR duration was 821 days and median patient survival was 894 days. In the study the results were significantly longer by 2.9 and 2.3 fold respectively when compared to those of 18 historical patient treatments with same regimen of combination chemotherapy without imatinib. [16]

Wassmann et al. enrolled 92 patients with newly diagnosed Ph+ ALL in a prospective multi‐ center study to investigate sequentially 2 treatment schedules with imatinib administrated concurrent to or alternating with a uniform induction and consolidation regimen. Coadmi‐ nistration of imatinib and induction cycle2 (INDII) resulted in a CR rate of 95 % and polymerase chain reaction (PCR) negativity for BCR/ABL in 52 % of the patients compared with 19% in patients in the alternating treatment cohort. Remarkably, patients with and without a CR after induction cycle 1 (INDI) had similar hematologic and molecular responses after concurrent imatinib and INDII. 7 % of the patients underwent allogeneic stem cell transplantation (SCT), in first CR (CR1) both schedules of imatinib had acceptable toxicity and facilitated SCT in CR1 in the majority of patients but concurrent administration of imatinib and chemotherapy had greater antileukemic efficacy for this group. [17]

Labarthe et al. in 2007 published the results of 45 patients with Ph+ ALL treated in the Group for Research on Adult Acute Lymphoblastic Leukemia (GRAAPH) 2003 study, where imatinib was started with HAM (mitoxantrone with intermediate-dose cytarabine) as consolidation therapy in good early responders (corticosensitive and chemosensitive ALL) or earlier during the induction course in combination with dexamethasone and vincristine in poor early responders (corticoresistant and/or chemoresistant ALL). Imati‐ nib was then continuously administered until stem cell transplantation (SCT). Overall, complete remission (CR) and *BCR-ABL* real-time quantitative polymerase chain reaction (RQ-PCR) negativity rates were 96% and 29%, respectively. All of the 22 CR patients (100%) with a donor received allogeneic SCT in first CR. At 18 months, the estimated cumulative incidence of relapse, disease-free survival, and overall survival were 30%, 51%, and 65%, respectively. The authors described these 3 end points were favorable compared with results obtained in the pre-imatinib LALA-94 trial. [18]

Ottmann et al. recognized the potential benefit of administering imatinib simultaneously with chemotherapy rather than in an alternating manner which was investigated in two successive cohort of patients who were treated according to GMALL protocol and received imatinib either alternating with chemotherapy (first cohort) or simultaneously with induction and consoli‐ dation cycles (second cohort). The reported rate of complete molecular remission (CMR) was 19% and 52 % respectively, but this greater antileukemia efficacy did not translate into significant improvements in DFS or overall survival. [19] So far, the analyzed data showed the superiority of adding Imatinib to conventional chemotherapy and it was strongly suggested by historical comparison between the outcome of the patients using similar chemotherapeutic with or without imatinib. The magnitude of improvement was as high as 30% in the studies from MD Anderson and the GRAALL. These results were also confirmed by a pediatric study of Schultz et al. in which imatinib was given at 340 mg/m2 for an increasing number of days in combination with intensive chemotherapy. Early (1 year) EFS improved with increasing imatinib exposure from 70% to 95%. [20]

1 year- relapse-free survival is 58 vs 11%. The author showed that the use of imatinib in elderly

**Table 2.** Studies combining imatinib with chemotherapy for de novo Philadelphia chromosome positive (Ph+) ALL in

Vinetti el al GIMEMA +Pred (800) Only (800) Only (800) 30 100 48 48 (1) 74 (1)

 **Imatinib dosing Results (%)**

**(mg/d) No CR Relapse DFS** 

Acute Lymphoblastic Leukemia (ALL) Philadelphia Positive…

**(at y)**

http://dx.doi.org/10.5772/55095

**Survival (at y)**

303

**Mantenance** 

AFR09 None C (600) A (600) 30 72 60 58 (1) 66 (1)

AFR07 pilot C (800) C (600) C (600) 31 90 NR 48 (1) 60 (1)

A pilot study of these combinations had shown promising results in relapsing and refractory Ph+ ALL with a CR rate of 90% in patients older than 55 years. This group, considers the hypothesis that Imatinib, combined with high-dose chemotherapy, is now becoming the gold standard for treatment of Philadelphia chromosome-positive acute leukemias. However, in all studies, imatinib dosage was tapered to 400–600 mg per day.) The group decided to initiate a clinical trial to evaluate an opposite strategy based on high-dose imatinib (800 mg per day) combined with a less intensive chemotherapeutic regimen (vincristine and dexamethasone), which we called the DIV induction regimen. Thirty-one patients (18 relapsing or refractory Ph + acute lymphoblastic leukemias and 13 lymphoid blast crisis chronic myelogenous leukemias) were enrolled. Complete remission (CR) was obtained in 28 out of 30 assessable patients. The median bcr-abl/abl ratio after the induction course was 0.1%. Median time to neutrophil recovery was 21 days. Nine out of 19 patients under 55 years old received allogenic stem cell transplantation after a median time of 78 days post-CR. Patients older than 55 experienced a 90% CR rate without additional toxicities, suggesting the DIV regimen may also be proposed

The combination of dasatinib with a variety of cytotoxic chemotherapy regimen both in younger and elderly patients with de novo or minimally pretreatment Ph+ ALL was explored in different groups of treatment. Ravandi et al. in one study phase II trial, showed patients with newly diagnosed Ph+ ALL who received dasatinib 50 mg PO BID (or 100 mg daily) for the first 14 days of each of 8 cycles of alternating hyperCVAD and high dose cytarabine plus methotrexate. Patients in CR continue to receive maintenance dasatinib 50 mg po BID (or 100 mg daily) and vincristine and prednisone monthly for 2 years followed by dasatinib indefi‐ nitely. With a median follow up of 10 months, 21 pts were alive and 18 were in CR; 2 died at induction, 3 pts died in CR; 1 from an unrelated cardiac event and 2 from infections. 5 pts relapsed (response durations were 54, 48, 47, 32, and 22 weeks) and 2 of them died. In 2 pts morphological relapse was preceded by flow and molecular relapse. Four relapsed pts

patients with Ph+ ALL is very likely to improve outcome, including OS. [22]

**Consolidation (mg/d)**

as a front line therapy in older patients.[23]

**Subtype**

Delannoy

Réa el al

Elderly Patients [10]

*Adults*

**Chemotherapy regimen**

GRAALL

GRAALL

**Induction (mg/d)**

**6. Dasatinib in combination with chemotherapy**

## **5. Imatinib-based therapy in elderly patients**

#### **5.1. Approach in older patients**

While the strategy of combining imatinib with standard intensive chemotherapy protocol was explored primarily in younger patients, therapeutic approaches in elderly patients were focused more on reducing the intensity of chemotherapy. Vignetti et al. by GIMEMA (LAL0201) initiated a study with 30 patients who received a prephase with prednisone at increasing doses from 10 to 40 mg/m2/day followed by 45 day induction treatment with imatinib at the fixed dose of 800mg /day in combination with oral prednisone (40mg/m2/day) followed by maintenance with imatinib in all responding patients until occurrence of disease relapse or excessive toxicity. Complete remission was achieved in all patients (n=29). median survival from diagnosis was 20 month. In this study, the authors showed that elderly Ph(+) patients with ALL, often considered eligible only for palliative treatment strategies,may benefit from an imatinib-steroids protocol, which does not require chemotherapy or a long hospital‐ ization; it is feasible, highly active, and associated with a good quality of life. [21]

Dalannoy et al., in another study from the GRALL (AFRO9 study), are currently testing a low intensity schedule (vincristine and dexamethasone), in combination with high dose imatinib (800mg/d) in elderly patients above 55 years (DIV regimen). Thirty patients were included in this study and were compared with 21 historical controls. Out of 29 assessable patients, 21 (72%9) were in CR after induction chemotherapy vs 6/21 (29%) in control. Five additional CRs were obtained after salvage with imatinib and four after salvage with additional chemotherapy in the control group. Overall survival (OS) was 66% at 1 year vs 43% in the control group. The


respectively. The authors described these 3 end points were favorable compared with

Ottmann et al. recognized the potential benefit of administering imatinib simultaneously with chemotherapy rather than in an alternating manner which was investigated in two successive cohort of patients who were treated according to GMALL protocol and received imatinib either alternating with chemotherapy (first cohort) or simultaneously with induction and consoli‐ dation cycles (second cohort). The reported rate of complete molecular remission (CMR) was 19% and 52 % respectively, but this greater antileukemia efficacy did not translate into significant improvements in DFS or overall survival. [19] So far, the analyzed data showed the superiority of adding Imatinib to conventional chemotherapy and it was strongly suggested by historical comparison between the outcome of the patients using similar chemotherapeutic with or without imatinib. The magnitude of improvement was as high as 30% in the studies from MD Anderson and the GRAALL. These results were also confirmed by a pediatric study of Schultz et al. in which imatinib was given at 340 mg/m2 for an increasing number of days in combination with intensive chemotherapy. Early (1 year) EFS improved with increasing

While the strategy of combining imatinib with standard intensive chemotherapy protocol was explored primarily in younger patients, therapeutic approaches in elderly patients were focused more on reducing the intensity of chemotherapy. Vignetti et al. by GIMEMA (LAL0201) initiated a study with 30 patients who received a prephase with prednisone at increasing doses from 10 to 40 mg/m2/day followed by 45 day induction treatment with imatinib at the fixed dose of 800mg /day in combination with oral prednisone (40mg/m2/day) followed by maintenance with imatinib in all responding patients until occurrence of disease relapse or excessive toxicity. Complete remission was achieved in all patients (n=29). median survival from diagnosis was 20 month. In this study, the authors showed that elderly Ph(+) patients with ALL, often considered eligible only for palliative treatment strategies,may benefit from an imatinib-steroids protocol, which does not require chemotherapy or a long hospital‐

ization; it is feasible, highly active, and associated with a good quality of life. [21]

Dalannoy et al., in another study from the GRALL (AFRO9 study), are currently testing a low intensity schedule (vincristine and dexamethasone), in combination with high dose imatinib (800mg/d) in elderly patients above 55 years (DIV regimen). Thirty patients were included in this study and were compared with 21 historical controls. Out of 29 assessable patients, 21 (72%9) were in CR after induction chemotherapy vs 6/21 (29%) in control. Five additional CRs were obtained after salvage with imatinib and four after salvage with additional chemotherapy in the control group. Overall survival (OS) was 66% at 1 year vs 43% in the control group. The

results obtained in the pre-imatinib LALA-94 trial. [18]

302 Clinical Epidemiology of Acute Lymphoblastic Leukemia - From the Molecules to the Clinic

imatinib exposure from 70% to 95%. [20]

**5.1. Approach in older patients**

**5. Imatinib-based therapy in elderly patients**

1 year- relapse-free survival is 58 vs 11%. The author showed that the use of imatinib in elderly patients with Ph+ ALL is very likely to improve outcome, including OS. [22]

A pilot study of these combinations had shown promising results in relapsing and refractory Ph+ ALL with a CR rate of 90% in patients older than 55 years. This group, considers the hypothesis that Imatinib, combined with high-dose chemotherapy, is now becoming the gold standard for treatment of Philadelphia chromosome-positive acute leukemias. However, in all studies, imatinib dosage was tapered to 400–600 mg per day.) The group decided to initiate a clinical trial to evaluate an opposite strategy based on high-dose imatinib (800 mg per day) combined with a less intensive chemotherapeutic regimen (vincristine and dexamethasone), which we called the DIV induction regimen. Thirty-one patients (18 relapsing or refractory Ph + acute lymphoblastic leukemias and 13 lymphoid blast crisis chronic myelogenous leukemias) were enrolled. Complete remission (CR) was obtained in 28 out of 30 assessable patients. The median bcr-abl/abl ratio after the induction course was 0.1%. Median time to neutrophil recovery was 21 days. Nine out of 19 patients under 55 years old received allogenic stem cell transplantation after a median time of 78 days post-CR. Patients older than 55 experienced a 90% CR rate without additional toxicities, suggesting the DIV regimen may also be proposed as a front line therapy in older patients.[23]

### **6. Dasatinib in combination with chemotherapy**

The combination of dasatinib with a variety of cytotoxic chemotherapy regimen both in younger and elderly patients with de novo or minimally pretreatment Ph+ ALL was explored in different groups of treatment. Ravandi et al. in one study phase II trial, showed patients with newly diagnosed Ph+ ALL who received dasatinib 50 mg PO BID (or 100 mg daily) for the first 14 days of each of 8 cycles of alternating hyperCVAD and high dose cytarabine plus methotrexate. Patients in CR continue to receive maintenance dasatinib 50 mg po BID (or 100 mg daily) and vincristine and prednisone monthly for 2 years followed by dasatinib indefi‐ nitely. With a median follow up of 10 months, 21 pts were alive and 18 were in CR; 2 died at induction, 3 pts died in CR; 1 from an unrelated cardiac event and 2 from infections. 5 pts relapsed (response durations were 54, 48, 47, 32, and 22 weeks) and 2 of them died. In 2 pts morphological relapse was preceded by flow and molecular relapse. Four relapsed pts

**Table 2.** Studies combining imatinib with chemotherapy for de novo Philadelphia chromosome positive (Ph+) ALL in Elderly Patients [10]

developed new ABL mutations (3 T315I and 1 F359V). One patient underwent an allogeneic stem cell transplant. The author concluded that Dasatinib with HyperCVAD is effective in achieved molecular remission in patients with Ph+ ALL. They also found high incidence of T 315I ABL mutation among the relapsed patients. [24]

patients were evaluable. All patients achieved a complete hematologic remission (CHR), 49 (92.5%) at day 22. At this time point, 10 patients achieved a BCR-ABL reduction to < 10−3. At 20 months, the overall survival was 69.2% and disease-free survival was 51.1%. A significant difference in DFS was observed between patients who showed a decrease in BCR-ABL levels to < 10−3 at day 22 compared with patients who never reached these levels during induction. No deaths or relapses occurred during induction. Twenty-three patients relapsed after completing induction. A T315I mutation was detected in 12 of 17 relapsed cases. Treatment was well tolerated; only 4 patients discontinued therapy during the last phase of the induction

associated with a CHR in virtually all patients, irrespective of age, good compliance, no deaths,

To date there is no consensus as to what constitutes the most effective maintenance therapy in patients in whom allogeneic SCT is not possible. The recommendations of the European Working Group for Adult ALL provide no recommendations for maintenance therapy in patients not eligible for allogenic stem cell transplantation. Usually Imatinib is given either alone or in combination with classical ALL maintenance such as low dose methotrexate and

Potenza et al. in a study, with seven patients with Ph+ ALL who were in first complete remission and received maintenance therapy with imatinib alone, at 2 year progression free survival was 75%. The qPCR monitoring of BCR/ABL, persisting molecular complete response was associated with long lasting CR. The molecular relapse did not invariably mean hemato‐ logical relapse and only the wide and rapid increment of BCR/ABL values was predictive of

However, larger studies show less favorable results with Imatinib based maintenance.

Hyper-CVAD and imatinib, then imatinib indefinitely. [10]

into better relapse free survival. [28-29]

M D Anderson employed more intensive maintenance therapy. They used imatinib 800 mg for 24 months with monthly vincristine and prednisone interrupted by 2 intensifications with

The GMALL A and GRAAL presented an interesting approach in which imatinib is given concurrently with standard dose of Interferon or peg –Interferon. Wassmann et al. had a hypothesis that the experimental data suggested that interferon-α (IFN-α) enhances the antileukemic activity of imatinib. Therefore, the group combined imatinib and low-dose IFNα in six patients with Ph+ ALL who were ineligible for stem cell transplantation. All patients had received imatinib for 0.5–4.8 months prior to IFN-α, for relapse or refractory Ph+ ALL or as an alternative to chemotherapy following severe treatment related toxicity. The results were encouraging, but longer follow up is needed to determine whether this strategy will translate

6-mercatopurine. However, data on the efficacy of these strategies is scarce. [22]

ALL, induction treatment with dasatinib plus steroids is

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when already in CHR. In adult Ph<sup>+</sup>

**8. Maintenance therapy**

leukemia relapse. [27]

and a very rapid de bulking of the neoplastic clone.[26]


*OS indicates overall survival; CR, complete remission; ChThx, chemotherapy; hyper-CVAD, fractionated cyclophosphamide, vincristine, doxorubicin, dexamethasone; IND, induction; na, not applicable; EWALL; European Working Group for Adult of the Europena LeukemiaNet*

\*22 patients with de novo Ph+All, 6pts, with one prior treatment cycle, OS indicates overall survival; CR, complete remission; ChThx, chemotherapy; hyper‐CVAD, fractionated cyclophosphamide, vincristine, doxorubicin, dexametha‐ sone; IND, induction; na, not applicable; EWALL; European Working Group for Adult of the Europena LeukemiaNet

**Table 3.** Studies with dasatinib for de novo Philadelphia chromosome + (Ph+) ALL.

In another study, Rousselot et al. evaluated that after a pre-phase with dexamethasone 10 mg/ m2 d-7 to d-3, dasatinib was administered at 140 mg QD (100 mg in patients over 70y) during the induction period in combination with IV injections of vincristine 1 mg and dexamethasone 40 mg 2 days (20 mg over 70y) repeated weekly for 4 weeks. Consolidation cycles consisted of dasatinib 100 mg/d administered sequentially with methotrexate 1000 mg/m2 IV d1 (500 mg/m2 over 70y) and L-asparaginase 10,000 UI/m2 IM d2 (5,000 UI/m2 over 70y) for cycles 1, 3 and 5 and cytarabine 1,000 mg/m2 /12h IV d1, d3, d5 (500 mg/m2 over 70y) for cycles 2, 4 and 6. Maintenance phase consisted of dasatinib alternating with 6-MP and methotrexate orally every other month and dexamethasone/vincristine once every 2 months for up to 24 months. Median RFS and OS were 22.1 and 27.1 months, respectively. The group also showed dasatinib with low-intensity chemotherapy was highly effective in elderly patients with Ph+ ALL with a 90% CR and 22.1 months RFS. In concordance with Ravandi et al. the mutation T315I was associated with relapses. [25]

In these studies the CR rates were from 93 % until 100% independent of the regimen used, with molecular remission rates from 28% to 72%.

#### **7. Dasatinib monotherapy**

Dasatinib was used without chemotherapy. In this modality Foa el al by GIMEMA LAL1205 protocol, the patients with newly diagnosed Ph+ ALL older than 18 (with no upper age limit) received dasatinib 70 mg BID IN induction therapy for 84 days combined with steroids for the first 32 days and intrathecal chemotherapy. Post-remission therapy was free. Fifty-three patients were evaluable. All patients achieved a complete hematologic remission (CHR), 49 (92.5%) at day 22. At this time point, 10 patients achieved a BCR-ABL reduction to < 10−3. At 20 months, the overall survival was 69.2% and disease-free survival was 51.1%. A significant difference in DFS was observed between patients who showed a decrease in BCR-ABL levels to < 10−3 at day 22 compared with patients who never reached these levels during induction. No deaths or relapses occurred during induction. Twenty-three patients relapsed after completing induction. A T315I mutation was detected in 12 of 17 relapsed cases. Treatment was well tolerated; only 4 patients discontinued therapy during the last phase of the induction when already in CHR. In adult Ph<sup>+</sup> ALL, induction treatment with dasatinib plus steroids is associated with a CHR in virtually all patients, irrespective of age, good compliance, no deaths, and a very rapid de bulking of the neoplastic clone.[26]

## **8. Maintenance therapy**

developed new ABL mutations (3 T315I and 1 F359V). One patient underwent an allogeneic stem cell transplant. The author concluded that Dasatinib with HyperCVAD is effective in achieved molecular remission in patients with Ph+ ALL. They also found high incidence of T

> **Schedule of TKI and ChThx CR %**

Post-Induction

*OS indicates overall survival; CR, complete remission; ChThx, chemotherapy; hyper-CVAD, fractionated cyclophosphamide, vincristine, doxorubicin, dexamethasone; IND, induction;*

\*22 patients with de novo Ph+All, 6pts, with one prior treatment cycle, OS indicates overall survival; CR, complete remission; ChThx, chemotherapy; hyper‐CVAD, fractionated cyclophosphamide, vincristine, doxorubicin, dexametha‐ sone; IND, induction; na, not applicable; EWALL; European Working Group for Adult of the Europena LeukemiaNet

In another study, Rousselot et al. evaluated that after a pre-phase with dexamethasone 10 mg/ m2 d-7 to d-3, dasatinib was administered at 140 mg QD (100 mg in patients over 70y) during the induction period in combination with IV injections of vincristine 1 mg and dexamethasone 40 mg 2 days (20 mg over 70y) repeated weekly for 4 weeks. Consolidation cycles consisted of dasatinib 100 mg/d administered sequentially with methotrexate 1000 mg/m2 IV d1 (500 mg/m2 over 70y) and L-asparaginase 10,000 UI/m2 IM d2 (5,000 UI/m2 over 70y) for cycles 1, 3

6. Maintenance phase consisted of dasatinib alternating with 6-MP and methotrexate orally every other month and dexamethasone/vincristine once every 2 months for up to 24 months. Median RFS and OS were 22.1 and 27.1 months, respectively. The group also showed dasatinib with low-intensity chemotherapy was highly effective in elderly patients with Ph+ ALL with a 90% CR and 22.1 months RFS. In concordance with Ravandi et al. the mutation T315I was

In these studies the CR rates were from 93 % until 100% independent of the regimen used, with

Dasatinib was used without chemotherapy. In this modality Foa el al by GIMEMA LAL1205

received dasatinib 70 mg BID IN induction therapy for 84 days combined with steroids for the first 32 days and intrathecal chemotherapy. Post-remission therapy was free. Fifty-three

**<sup>2008</sup>** 28\* 52(21-79) 100 QD HyperCVAD D1-14 of e/cycle 93 50 2(7) 5(18) CR (10m):18 (64%)

**PCR negative %**

/12h IV d1, d3, d5 (500 mg/m2 over 70y) for cycles 2, 4 and

ALL older than 18 (with no upper age limit)

then 95 28 1 (4.5) 1 (4.5) na

therapy not 100 na 0 9 (27) OS (10): 81%

**Induction death, n(&)**

**Relapse** 

**% Outcome**

OS (10): 21 (75%

315I ABL mutation among the relapsed patients. [24]

304 Clinical Epidemiology of Acute Lymphoblastic Leukemia - From the Molecules to the Clinic

**Dasatinib mg/d**

**ChThx regimen**

100 QD EWALL elderly IND: parallel,

then 12 w

**Table 3.** Studies with dasatinib for de novo Philadelphia chromosome + (Ph+) ALL.

**Age (range)**

**<sup>2008</sup>** 48 (34) 54 (24-76) 70 BID Steroid prephase

*na, not applicable; EWALL; European Working Group for Adult of the Europena LeukemiaNet*

*\*22 patients with de novo Ph+All, 6pts, with one prior treatment cycle*

and 5 and cytarabine 1,000 mg/m2

associated with relapses. [25]

**7. Dasatinib monotherapy**

molecular remission rates from 28% to 72%.

protocol, the patients with newly diagnosed Ph+

**Reference <sup>N</sup>**

**Ravandi F** 

**Rousselot P** 

**Foa R** 

**(evaluated)**

**<sup>2008</sup>** 22 71 (61-83) 140 QD

To date there is no consensus as to what constitutes the most effective maintenance therapy in patients in whom allogeneic SCT is not possible. The recommendations of the European Working Group for Adult ALL provide no recommendations for maintenance therapy in patients not eligible for allogenic stem cell transplantation. Usually Imatinib is given either alone or in combination with classical ALL maintenance such as low dose methotrexate and 6-mercatopurine. However, data on the efficacy of these strategies is scarce. [22]

Potenza et al. in a study, with seven patients with Ph+ ALL who were in first complete remission and received maintenance therapy with imatinib alone, at 2 year progression free survival was 75%. The qPCR monitoring of BCR/ABL, persisting molecular complete response was associated with long lasting CR. The molecular relapse did not invariably mean hemato‐ logical relapse and only the wide and rapid increment of BCR/ABL values was predictive of leukemia relapse. [27]

However, larger studies show less favorable results with Imatinib based maintenance.

M D Anderson employed more intensive maintenance therapy. They used imatinib 800 mg for 24 months with monthly vincristine and prednisone interrupted by 2 intensifications with Hyper-CVAD and imatinib, then imatinib indefinitely. [10]

The GMALL A and GRAAL presented an interesting approach in which imatinib is given concurrently with standard dose of Interferon or peg –Interferon. Wassmann et al. had a hypothesis that the experimental data suggested that interferon-α (IFN-α) enhances the antileukemic activity of imatinib. Therefore, the group combined imatinib and low-dose IFNα in six patients with Ph+ ALL who were ineligible for stem cell transplantation. All patients had received imatinib for 0.5–4.8 months prior to IFN-α, for relapse or refractory Ph+ ALL or as an alternative to chemotherapy following severe treatment related toxicity. The results were encouraging, but longer follow up is needed to determine whether this strategy will translate into better relapse free survival. [28-29]

Longer follow up is needed to determine if this strategy will translate into better relapse-free survival. The European recommendation concluded that the standard approach to de novo Ph + ALL is the combination of intensive chemotherapy with imatinib (400 mg/d to 800/d) in young patients and reduced dose of chemotherapy with high dose imatinib (600 mg/d to 800 mg/d) for elderly patients. Allogeneic SCT is recommended to all eligible patients with a suitable donor and to continue imatinib with or without additional therapy in patients not undergoing SCT.[30]

**11. Relapse associated with a BCR-ABL kinase domain point mutation**

to the second-generation TKIs nilotinib and dasatinib.[39]

by the second-generation TKI dasatinib.[39]

The development of clinical resistance to imatinib has now surfaced in several sites. Acquisitions of point mutations in the ABL tyrosine kinase domain (KD) that interfere with the binding of imatinib appear to be the most influential. ABL KD mutations generally are comprised of two categories. The first includes mutations that directly impede contact between imatinib and Bcr-Abl, such as the gatekeeper mutations T3151 or F317L. [35] The second involves mutations that alter the spatial conformation of the Bcr-Abl protein by affecting one of the two flexible loops: (1) the P-loop containing the ATP binding pocket, or (2) the activating loop. [36.37.38] To date, more than 50 ABL KD mutations have been identified. Although the prognostic significance of many of these remains unclear, the T315I mutation has been associated with a particularly adverse outcome since it disrupts a hydrogen bond critical for binding the TKI to the ATP- binding site. It has been identi‐ fied in up to 20% of patients with imatinib-resistant Ph+ ALL, and also confers resistance

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In the GMALL study for elderly patients with Ph+ ALL, the incidence of ABL mutations by direct cDNA sequencing at the time of disease recurrence was 84%. In patients with ABL KD mutations, P-loop mutations predominated at a frequency of 57%, followed by the T315I mutation at 19%. The mutated clone comprised more than 50% of the ABL clones in all patients. [20] Pfeifer et al. also demonstrated that these ABL KD mutations were present in nearly 40% of the patients with de novo imatinib-naïve Ph+ ALL, with a distribution of P-loop mutations in 80% and the T315I mutation in 17%. However, the mutated ABL clone always comprised less than 2% of the sample, in contrast to the predominance of the mutated clone when associated with disease recurrence. These low-level ABL KD mutations in imatinib-naïve samples required more sensitive methods for detection (e.g., high-performance liquid chro‐ matography). The presence of ABL KD mutations prior to imatinib did not correlate with known prognostic factors. There was no difference in the probability of achieving CR or molecular response based on the presence or absence of ABL KD mutations prior to imatinib therapy. No difference in remission duration was observed other than for those with the T315I mutation, which adversely affected outcome. In nearly all patients with an ABL KD mutation identified pretreatment, the same mutation was noted at the time of disease recurrence. Approximately 67% of the patients without an ABL KD mutation detected prior to imatinib had developed one at the time of disease recurrence. The discovery of novel acquired ABL KD mutations had also been reported in Ph+ ALL after sequential therapy with imatinib followed

Soverini et al. reported the development of the T315A and F317I (as opposed to the T315I or F317L) mutations that have inherent resistance to dasatinib. These ABL KD mutations could be suppressed by either imatinib or nilotinib given the lower IC50 with these compounds, although retreatment with imatinib after a prior failure would likely be ineffective due to the potential role of other coexisting mechanisms of resistance. Resistance screening with nilotinib, the other second-generation TKI, yielded only a limited spectrum of point mutations.[40] This

## **9. Central nervous system (CNS) prophylaxis**

Central nervous system leukemia is infrequent (5%) at initial presentation, but there is significant risk of developing meningeal leukemia during the course of treatment and the CNS directed prophylactic therapy should be considered mandatory in this patients.

Imatinib does not cross the blood brain barrier to an appreciable extent, levels in the cerebro‐ spinal fluid have shown to reach approximately 1 - 2 % of serum level. This low degree of penetration into the CNS is most likely due to p-glycoprotein export pumps, and it is not increased in the setting of active meningeal leukemia. Therefore, active CNS directed prophy‐ lactic therapy is mandatory in all patients with Ph+ ALL. Both repeat intrathecal injection of chemotherapy e.g. methotrexate, alone or in combination with cytarabine and corticosteroid, and prophylactic cranial irradiation have been used successfully. There is currently no conclusive data whether for how long and at what interval intratecal chemotherapy should be continued in patients with sustained hematological even molecular remission and whether it may be prudent to administer some form of CNS prophylactic after SCT.[31,32]

Dasatinib showed in the clinical trials CA180006 better penetration of the CSF and achieved clinically active concentrations in small series of patients in whom stabilization and regression of CNS disease were achieved. The doses of Dasatinib 140 mg once a day or 70 mg twice a day. It remains to be determined whether the current approach to CNS directed prophylaxis can be modified in the context of dasatinib based treatment.[33]

### **10. Mechanism of resistance to therapy and progression**

The mechanism of resistance to therapy is related to acquired genetic abnormalities in Ph+ ALL blast cells, which provide insights into pathogenesis and strongly influence prognosis. Cytogenetic abnormalities in addition to the Ph+ chromosome are present in approximately one third of cases of adult leukemia. Other Overexpression of bcr/abl fusion gene e.g. due to double Ph+ chromosome, activates a number of downstream signaling pathways involving the Ras/Raf/mitogen activated protein kinase and JAK-STAT (Janus Kinase signal transducer and transcription activator of transcription) development of growth factor independent malignant clones contributes to progression of the disease. [34]

## **11. Relapse associated with a BCR-ABL kinase domain point mutation**

Longer follow up is needed to determine if this strategy will translate into better relapse-free survival. The European recommendation concluded that the standard approach to de novo Ph + ALL is the combination of intensive chemotherapy with imatinib (400 mg/d to 800/d) in young patients and reduced dose of chemotherapy with high dose imatinib (600 mg/d to 800 mg/d) for elderly patients. Allogeneic SCT is recommended to all eligible patients with a suitable donor and to continue imatinib with or without additional therapy in patients not

Central nervous system leukemia is infrequent (5%) at initial presentation, but there is significant risk of developing meningeal leukemia during the course of treatment and the CNS

Imatinib does not cross the blood brain barrier to an appreciable extent, levels in the cerebro‐ spinal fluid have shown to reach approximately 1 - 2 % of serum level. This low degree of penetration into the CNS is most likely due to p-glycoprotein export pumps, and it is not increased in the setting of active meningeal leukemia. Therefore, active CNS directed prophy‐ lactic therapy is mandatory in all patients with Ph+ ALL. Both repeat intrathecal injection of chemotherapy e.g. methotrexate, alone or in combination with cytarabine and corticosteroid, and prophylactic cranial irradiation have been used successfully. There is currently no conclusive data whether for how long and at what interval intratecal chemotherapy should be continued in patients with sustained hematological even molecular remission and whether it

Dasatinib showed in the clinical trials CA180006 better penetration of the CSF and achieved clinically active concentrations in small series of patients in whom stabilization and regression of CNS disease were achieved. The doses of Dasatinib 140 mg once a day or 70 mg twice a day. It remains to be determined whether the current approach to CNS directed prophylaxis can

The mechanism of resistance to therapy is related to acquired genetic abnormalities in Ph+ ALL blast cells, which provide insights into pathogenesis and strongly influence prognosis. Cytogenetic abnormalities in addition to the Ph+ chromosome are present in approximately one third of cases of adult leukemia. Other Overexpression of bcr/abl fusion gene e.g. due to double Ph+ chromosome, activates a number of downstream signaling pathways involving the Ras/Raf/mitogen activated protein kinase and JAK-STAT (Janus Kinase signal transducer and transcription activator of transcription) development of growth factor independent

directed prophylactic therapy should be considered mandatory in this patients.

may be prudent to administer some form of CNS prophylactic after SCT.[31,32]

be modified in the context of dasatinib based treatment.[33]

**10. Mechanism of resistance to therapy and progression**

malignant clones contributes to progression of the disease. [34]

undergoing SCT.[30]

**9. Central nervous system (CNS) prophylaxis**

306 Clinical Epidemiology of Acute Lymphoblastic Leukemia - From the Molecules to the Clinic

The development of clinical resistance to imatinib has now surfaced in several sites. Acquisitions of point mutations in the ABL tyrosine kinase domain (KD) that interfere with the binding of imatinib appear to be the most influential. ABL KD mutations generally are comprised of two categories. The first includes mutations that directly impede contact between imatinib and Bcr-Abl, such as the gatekeeper mutations T3151 or F317L. [35] The second involves mutations that alter the spatial conformation of the Bcr-Abl protein by affecting one of the two flexible loops: (1) the P-loop containing the ATP binding pocket, or (2) the activating loop. [36.37.38] To date, more than 50 ABL KD mutations have been identified. Although the prognostic significance of many of these remains unclear, the T315I mutation has been associated with a particularly adverse outcome since it disrupts a hydrogen bond critical for binding the TKI to the ATP- binding site. It has been identi‐ fied in up to 20% of patients with imatinib-resistant Ph+ ALL, and also confers resistance to the second-generation TKIs nilotinib and dasatinib.[39]

In the GMALL study for elderly patients with Ph+ ALL, the incidence of ABL mutations by direct cDNA sequencing at the time of disease recurrence was 84%. In patients with ABL KD mutations, P-loop mutations predominated at a frequency of 57%, followed by the T315I mutation at 19%. The mutated clone comprised more than 50% of the ABL clones in all patients. [20] Pfeifer et al. also demonstrated that these ABL KD mutations were present in nearly 40% of the patients with de novo imatinib-naïve Ph+ ALL, with a distribution of P-loop mutations in 80% and the T315I mutation in 17%. However, the mutated ABL clone always comprised less than 2% of the sample, in contrast to the predominance of the mutated clone when associated with disease recurrence. These low-level ABL KD mutations in imatinib-naïve samples required more sensitive methods for detection (e.g., high-performance liquid chro‐ matography). The presence of ABL KD mutations prior to imatinib did not correlate with known prognostic factors. There was no difference in the probability of achieving CR or molecular response based on the presence or absence of ABL KD mutations prior to imatinib therapy. No difference in remission duration was observed other than for those with the T315I mutation, which adversely affected outcome. In nearly all patients with an ABL KD mutation identified pretreatment, the same mutation was noted at the time of disease recurrence. Approximately 67% of the patients without an ABL KD mutation detected prior to imatinib had developed one at the time of disease recurrence. The discovery of novel acquired ABL KD mutations had also been reported in Ph+ ALL after sequential therapy with imatinib followed by the second-generation TKI dasatinib.[39]

Soverini et al. reported the development of the T315A and F317I (as opposed to the T315I or F317L) mutations that have inherent resistance to dasatinib. These ABL KD mutations could be suppressed by either imatinib or nilotinib given the lower IC50 with these compounds, although retreatment with imatinib after a prior failure would likely be ineffective due to the potential role of other coexisting mechanisms of resistance. Resistance screening with nilotinib, the other second-generation TKI, yielded only a limited spectrum of point mutations.[40] This suggests a lower rate of ABL KD mutations after Nilotinib therapy; however, additional analyses of ongoing clinical trials are needed to support this contention. [41]

**13. Treatment to relapse**

3 of whom had CNS involvement. [50]

generation ABL TKI. [50]

**14. New kinase inhibitors**

Point mutations are the major mechanism of resistance to Imatinib therapy in Ph+ leukemia; different drugs active on mutant BCR/ABL or on its signal transduction pathway have been developed and tested at clinical level. Several second-generation ABL TKIs possess significant activity against imatinib-resistant BCR/ABL mutants, although their specificities vary.[48] Dasatinib has been tested most extensively in Ph+ ALL and has been approved as second-line treatment of bcr-abl–positive leukemias in first time. Dasatinib (formerly BMS-354825) is a multitarget kinase inhibitor of Bcr-Abl, SRC family kinases, ephrin receptor kinases, PDGFR and KIT, among others. In a phase II study, dasatinib induces rapid hematologic and cytoge‐ netic responses in adult patients with Ph+ ALL with resistance or intolerance to imatinib.[49] Non-hematological side effects include diarrhea, nausea, headache, peripheral edema and pleural effusion. However, remission duration and PFS were short, due to resistance that was often associated with appearance of the T315I mutation. To enhance efficacy, dasatinib was combined with the hyperCVAD chemotherapy regimen in a phase II study with 14 patients,

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All patients responded; 71% achieved a CR, 64% achieved a major molecular response. With a median follow-up of 6 months, 7 patients remained in CR/CRp. Although toxicity was significant, with several episodes of gastrointestinal and subdural hemorrhage and pleural effusions, these preliminary results suggested that combination therapy should be preferred over single-agent therapy; alloSCT should be the goal if at all possible. To achieve a CR, mutation analysis should precede salvage therapy, and experimental treatment should be considered if the T315I mutation is detected, as this mutation confers resistance to all second

Small-molecule inhibitors developed to target Aurora kinases (AK), a family of serinethreonine kinases involved in the control of chromosome assembly and segregation during mitosis, have been found to possess activity against the T315I mutation. Several of these novel

Another novel chemical class of compounds that bind to different structural pockets used by ABL kinase to switch between the inactive and active conformations, have recently been developed using structure-based drug design. Compounds have emerged that potently inhibit purified ABL in both the unphosphorylated and phosphorylated states via a non-ATPcompetitive mechanism and impair proliferation and induce apoptosis of cells expressing a wide variety of BCR-ABL TKI-resistant mutants, including the T315I mutant, many P-loop

Ongoing and future clinical trials will establish whether front-line therapy with secondgeneration ABL kinase inhibitors, ie, dasatinib, nilotinib, bosutinib and Inno-406, are superior

AK inhibitors have recently entered preclinical or clinical testing.. [51.52]

mutants, and the dasatinib- resistant mutant F317L. [53]

Other mechanisms of resistance to imatinib and other TKIs include increased drug efflux, amplification of the BCR-ABL gene, and signaling independence of BCR-ABL after secondary transforming events (e.g., Src kinase pathway). Theoretically, dose escalation of imatinib or the use of more potent ABL inhibitors could circumvent the first two events, whereas use of novel Src inhibitors or multitargeted inhibitors would be required to restore sensitivity in the latter case [42]

## **12. Clinical implications of MRD**

High levels of bcr-abl transcripts at different treatment stages indicate poor responsiveness to chemotherapy and to TKI, and intuitively could be considered a risk factor for disease recurrence. However, published data is not consistent. MRD levels determined at different time points prior to alloSCT were found to have prognostic relevance, with an early reduction in BCR-ABL transcript levels of at least 3 log appearing as the most powerful predictor of lower relapse rate and better DFS. The authors demonstrated the positive impact of imatinib on the outcome of allogeneic stem cell transplantation in adults with Philadelphia chromosomepositive acute lymphoblastic leukemia (Ph-positive ALL)and analyzed for risk factors that affect transplantation outcome, and they focused particularly on the prognostic relevance of minimal residual disease levels at each treatment stage. Prospective assessment of the extent of minimal residual disease reduction after the first 4-week imatinib therapy may allow the authors to identify subgroups of Ph-positive ALL transplants at high risk of relapse. [45] Stratification based upon MRD levels was also the principal prognostic parameter in two studies, Dombret H. et al. with 154 patients, and Pane F et al with 45 Ph+ ALL patients, respectively. [43,44,45,46]

In contrast, prospective MRD monitoring in 100 adult patients with Ph+ ALL treated with uniform imatinib- combined chemotherapy failed to establish an association between PCR negativity at the end of induction therapy and either relapse rate or relapse-free survival, although an increase in bcr-abl transcripts during hematologic CR was predictive of relapse in non-transplanted patients. [47]

Despite these discrepancies, these studies demonstrate that prospective monitoring of MRD has the potential to identify patients at risk of relapse, although the implication of different transcript levels and increments require validation within each therapeutic context or clinical study. These issues highlight the need for standardization and harmonization of methodolo‐ gies used for bcr-abl quantification in Ph+ ALL. To achieve this aim at an international level, regular quality control rounds are jointly conducted by the European Working Group for Adult ALL (EWALL) of the European LeukemiaNet and the European Study Group for MRD Analysis in Acute Lymphoblastic Leukemia.

## **13. Treatment to relapse**

suggests a lower rate of ABL KD mutations after Nilotinib therapy; however, additional

Other mechanisms of resistance to imatinib and other TKIs include increased drug efflux, amplification of the BCR-ABL gene, and signaling independence of BCR-ABL after secondary transforming events (e.g., Src kinase pathway). Theoretically, dose escalation of imatinib or the use of more potent ABL inhibitors could circumvent the first two events, whereas use of novel Src inhibitors or multitargeted inhibitors would be required to restore sensitivity in the

High levels of bcr-abl transcripts at different treatment stages indicate poor responsiveness to chemotherapy and to TKI, and intuitively could be considered a risk factor for disease recurrence. However, published data is not consistent. MRD levels determined at different time points prior to alloSCT were found to have prognostic relevance, with an early reduction in BCR-ABL transcript levels of at least 3 log appearing as the most powerful predictor of lower relapse rate and better DFS. The authors demonstrated the positive impact of imatinib on the outcome of allogeneic stem cell transplantation in adults with Philadelphia chromosomepositive acute lymphoblastic leukemia (Ph-positive ALL)and analyzed for risk factors that affect transplantation outcome, and they focused particularly on the prognostic relevance of minimal residual disease levels at each treatment stage. Prospective assessment of the extent of minimal residual disease reduction after the first 4-week imatinib therapy may allow the authors to identify subgroups of Ph-positive ALL transplants at high risk of relapse. [45] Stratification based upon MRD levels was also the principal prognostic parameter in two studies, Dombret H. et al. with 154 patients, and Pane F et al with 45 Ph+ ALL patients,

In contrast, prospective MRD monitoring in 100 adult patients with Ph+ ALL treated with uniform imatinib- combined chemotherapy failed to establish an association between PCR negativity at the end of induction therapy and either relapse rate or relapse-free survival, although an increase in bcr-abl transcripts during hematologic CR was predictive of relapse

Despite these discrepancies, these studies demonstrate that prospective monitoring of MRD has the potential to identify patients at risk of relapse, although the implication of different transcript levels and increments require validation within each therapeutic context or clinical study. These issues highlight the need for standardization and harmonization of methodolo‐ gies used for bcr-abl quantification in Ph+ ALL. To achieve this aim at an international level, regular quality control rounds are jointly conducted by the European Working Group for Adult ALL (EWALL) of the European LeukemiaNet and the European Study Group for MRD

analyses of ongoing clinical trials are needed to support this contention. [41]

308 Clinical Epidemiology of Acute Lymphoblastic Leukemia - From the Molecules to the Clinic

latter case [42]

respectively. [43,44,45,46]

in non-transplanted patients. [47]

Analysis in Acute Lymphoblastic Leukemia.

**12. Clinical implications of MRD**

Point mutations are the major mechanism of resistance to Imatinib therapy in Ph+ leukemia; different drugs active on mutant BCR/ABL or on its signal transduction pathway have been developed and tested at clinical level. Several second-generation ABL TKIs possess significant activity against imatinib-resistant BCR/ABL mutants, although their specificities vary.[48]

Dasatinib has been tested most extensively in Ph+ ALL and has been approved as second-line treatment of bcr-abl–positive leukemias in first time. Dasatinib (formerly BMS-354825) is a multitarget kinase inhibitor of Bcr-Abl, SRC family kinases, ephrin receptor kinases, PDGFR and KIT, among others. In a phase II study, dasatinib induces rapid hematologic and cytoge‐ netic responses in adult patients with Ph+ ALL with resistance or intolerance to imatinib.[49]

Non-hematological side effects include diarrhea, nausea, headache, peripheral edema and pleural effusion. However, remission duration and PFS were short, due to resistance that was often associated with appearance of the T315I mutation. To enhance efficacy, dasatinib was combined with the hyperCVAD chemotherapy regimen in a phase II study with 14 patients, 3 of whom had CNS involvement. [50]

All patients responded; 71% achieved a CR, 64% achieved a major molecular response. With a median follow-up of 6 months, 7 patients remained in CR/CRp. Although toxicity was significant, with several episodes of gastrointestinal and subdural hemorrhage and pleural effusions, these preliminary results suggested that combination therapy should be preferred over single-agent therapy; alloSCT should be the goal if at all possible. To achieve a CR, mutation analysis should precede salvage therapy, and experimental treatment should be considered if the T315I mutation is detected, as this mutation confers resistance to all second generation ABL TKI. [50]

Small-molecule inhibitors developed to target Aurora kinases (AK), a family of serinethreonine kinases involved in the control of chromosome assembly and segregation during mitosis, have been found to possess activity against the T315I mutation. Several of these novel AK inhibitors have recently entered preclinical or clinical testing.. [51.52]

Another novel chemical class of compounds that bind to different structural pockets used by ABL kinase to switch between the inactive and active conformations, have recently been developed using structure-based drug design. Compounds have emerged that potently inhibit purified ABL in both the unphosphorylated and phosphorylated states via a non-ATPcompetitive mechanism and impair proliferation and induce apoptosis of cells expressing a wide variety of BCR-ABL TKI-resistant mutants, including the T315I mutant, many P-loop mutants, and the dasatinib- resistant mutant F317L. [53]

## **14. New kinase inhibitors**

Ongoing and future clinical trials will establish whether front-line therapy with secondgeneration ABL kinase inhibitors, ie, dasatinib, nilotinib, bosutinib and Inno-406, are superior to imatinib. Results may differ depending on their use as single-agents or as components for combination therapy. SCT-independent immunotherapeutic approaches are also evolving. Bispecific T cell–engager (BiTE) antibodies that transiently engage cytotoxic T cells for lysis of selected target cells are among the most interesting agents for immunotherapy of Ph+ ALL. The bispecific antibody construct called blinatumomab links T cells with CD19-expressing target cells, resulting in a non-restricted cytotoxic T-cell response and T-cell activation. A phase II dose-escalating study investigating the efficacy and safety of blinatumomab in ALL patients who are in complete hematological remission but remain MRD-positive is ongoing. Prelimi‐ nary results indicate that treatment with blinatumomab is well tolerated and able to convert MRD- positive ALL into an MRD negative status. [54]

**Author details**

and Jorge Milone

\*Address all correspondence to: enrico@netverk.com.ar

Hematology Area Hospital Italiano de la Plata, Argentina

[1] Fadert S, Jeha S, Kantarjian H et al. The biology and Therapy of adult acute lympho‐

Acute Lymphoblastic Leukemia (ALL) Philadelphia Positive…

http://dx.doi.org/10.5772/55095

311

[2] Milone J, Enrico A -Treatment of Philadelphia chromosome-positive acute lympho‐

[3] The groupe francais de cytogenetique hematologique. Cytogenetic abnormalities in adult acute lymphoblastic leukemia; correlations with hematologic finding and out‐ come. A collaborative study of the groupe francaise de cytogenetique hematologi‐

[4] Burmeister T, Schwartz S, Bartram CR, et al. Pacients age and BCR-ABL, frequency in adult B-precursor ALL: a retrospective analysis from the GMALL study group Boold

[5] Moorman AV, Harrison CJ, Buck GA et al. Adult leukemia Working Party Medical Research Council National Cancer Research Council National Cancer Research Insti‐ tute. Karyotype is an independent prognosis factor in adult acute lymphoblastic leu‐ kemia (ALL) analysis of cytogenetic data from patients treated on the medical research council (MRC) UKALLXII/Eastern Cooperative Oncology Group (ECOG)

[6] Yanada M, Takeuchi J, Sugiura I et al. Japan Adult Leukemia Study Group Karyo‐ type at diagnosis is the major prognostic factor predicting relapse-free survival for patients with Philadelphia chromosome-positive acute lymphoblastic leukemia treat‐

[7] Bene MC, Castolddi G et al. Proposal of the immunological calssifications of acute leukemias. European Group for the immunological characterizations of Leukemias

[8] World Health OrganizationClassification of Tumor, Pathology and Genetics of Tu‐

[9] Ottmann G, and Wassmann B, treatment of Philadelphia chromosome positive Acute Lymphoblastic leukemia. American Society of Hematology 2005. Blood 118-122

ed with imatinib-combined chemotherapy Hematologica 2008;93:287-90

blastic leukemia. Cancer October 1 2003 volume 98 number 7 1337-1354

Alicia Enrico\*

**References**

blastic leukemia

2008: 112:918-919

que . Blood 1996; 87; 3135-3142

2993 trial Blood 2007; 109; 3189-97.

(EGIL) Leukemia 1995, 10 1783-6.

mors of Haematopoietic and Lymphoid Tissues. 2001

As a conclusion, our armamentarium of drugs that hold promise as active agents for treating Ph+ ALL is expanding substantially. Studies will need to focus on drug combinations, with specific attention to sequence and dosing of these agents. In designing trials, treatment algorithms should increasingly be based on molecular markers of disease and utilize quanti‐ tative assessment of MRD, and highly sensitive detection of mutations.[55]

#### **15. Conclusion**

The tyrosine kinase inhibitor (TKI) imatinib has become an integral part of front-line therapy for Ph+ ALL, with remission rates exceeding 90% irrespective of whether imati‐ nib is given alone or combined with chemotherapy. Treatment outcome with imatinibbased regimens has improved compared with historic controls, but most patients who do not undergo allogeneic stem cell transplantation (SCT) (see the next chapter) eventually relapse. Acquired resistance on TKI treatment is associated with mutations in the bcr-abl tyrosine kinase domain in the majority of patients, and may be detected at low frequency prior to TKI treatment in a subset of patients. Second generation TKIs, eg, dasatinib and nilotinib, show activity against most of the bcr-abl tyrosine kinase domain (TKD) muta‐ tions involved in acquired imatinib resistance, but clinical benefit is generally short-lived. Accordingly, SCT in first complete remission (CR) is considered to be the best curative option. Molecular monitoring of minimal residual disease levels appears to have prognos‐ tic relevance and should be used to guide treatment. International standardization and quality control efforts are ongoing to ensure comparability of results. Mutation analysis during treatment relies increasingly on highly sensitive PCR techniques or denaturing and may assist in treatment decisions, e.g., in cases of molecular relapse. Results from current studies of second-generation TKI as front-line treatment for Ph+ ALL are promising and show high molecular response rates, but follow-up is still too short to determine their impact on remission duration and long-term survival. Strategies to improve outcome after SCT include the pre-emptive use of imatinib, which appears to reduce the relapse rate. In patients ineligible for transplantation, novel concepts for maintenance therapy are need‐ ed. These could involve novel immunotherapeutic interventions and combinations of TKI.

## **Author details**

to imatinib. Results may differ depending on their use as single-agents or as components for combination therapy. SCT-independent immunotherapeutic approaches are also evolving. Bispecific T cell–engager (BiTE) antibodies that transiently engage cytotoxic T cells for lysis of selected target cells are among the most interesting agents for immunotherapy of Ph+ ALL. The bispecific antibody construct called blinatumomab links T cells with CD19-expressing target cells, resulting in a non-restricted cytotoxic T-cell response and T-cell activation. A phase II dose-escalating study investigating the efficacy and safety of blinatumomab in ALL patients who are in complete hematological remission but remain MRD-positive is ongoing. Prelimi‐ nary results indicate that treatment with blinatumomab is well tolerated and able to convert

As a conclusion, our armamentarium of drugs that hold promise as active agents for treating Ph+ ALL is expanding substantially. Studies will need to focus on drug combinations, with specific attention to sequence and dosing of these agents. In designing trials, treatment algorithms should increasingly be based on molecular markers of disease and utilize quanti‐

The tyrosine kinase inhibitor (TKI) imatinib has become an integral part of front-line therapy for Ph+ ALL, with remission rates exceeding 90% irrespective of whether imati‐ nib is given alone or combined with chemotherapy. Treatment outcome with imatinibbased regimens has improved compared with historic controls, but most patients who do not undergo allogeneic stem cell transplantation (SCT) (see the next chapter) eventually relapse. Acquired resistance on TKI treatment is associated with mutations in the bcr-abl tyrosine kinase domain in the majority of patients, and may be detected at low frequency prior to TKI treatment in a subset of patients. Second generation TKIs, eg, dasatinib and nilotinib, show activity against most of the bcr-abl tyrosine kinase domain (TKD) muta‐ tions involved in acquired imatinib resistance, but clinical benefit is generally short-lived. Accordingly, SCT in first complete remission (CR) is considered to be the best curative option. Molecular monitoring of minimal residual disease levels appears to have prognos‐ tic relevance and should be used to guide treatment. International standardization and quality control efforts are ongoing to ensure comparability of results. Mutation analysis during treatment relies increasingly on highly sensitive PCR techniques or denaturing and may assist in treatment decisions, e.g., in cases of molecular relapse. Results from current studies of second-generation TKI as front-line treatment for Ph+ ALL are promising and show high molecular response rates, but follow-up is still too short to determine their impact on remission duration and long-term survival. Strategies to improve outcome after SCT include the pre-emptive use of imatinib, which appears to reduce the relapse rate. In patients ineligible for transplantation, novel concepts for maintenance therapy are need‐ ed. These could involve novel immunotherapeutic interventions and combinations of TKI.

tative assessment of MRD, and highly sensitive detection of mutations.[55]

MRD- positive ALL into an MRD negative status. [54]

310 Clinical Epidemiology of Acute Lymphoblastic Leukemia - From the Molecules to the Clinic

**15. Conclusion**

Alicia Enrico\* and Jorge Milone

\*Address all correspondence to: enrico@netverk.com.ar

Hematology Area Hospital Italiano de la Plata, Argentina

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**Chapter 14**

**Invasive Fungal Infections in ALL Patients**

The success rate of acute lymphoblastic leukemia (ALL) therapy has gradually increased over the past decades. With more than 80% long-term survivors, treatment of ALL in children is undoubtedly one of the great success stories of innovative study-controlled modern medicine [1]. Attempts to boost cure rates for those who do not respond to therapy or relapse with more intense chemotherapy including allogeneic hematopoietic stem cell transplantation have further improved the outcome of patients, particularly for prognostic unfavorable subgroups [2]. However, intensification of treatment can substantially increase morbidity, the risk for life-

Several studies address this important issue and report on the emergence of fungi. A retro‐ spective review of ~ 5.600 patients who underwent hematopoietic stem cell transplantation at the Fred Hutchinson Cancer Research Center (Seattle) from 1985 to 1999 reports a constant increase of 3.5% in the one-year cumulative incidence of probable and proven invasive fungal infections [3]. Investigation of autopsies, skin, and lung biopsies, and bronchoalveolar lavage fluid analyses reveal that non-fumigatus Aspergillus species, such as Fusarium and Zygomy‐ cetes have increased, especially in patients, who have received multiple transplants. These observations are particular worrisome given the increasing importance of amphothericin-B resistant organisms, resulting in a very poor one-year survival rate of ~ 20% [4]. For those who do survive, length of hospital stay and total hospital charges are increased, compared with

Despite much effort has been taken to improve therapeutic treatments and strategies, there still remains much uncertainty and controversy regarding the best method to diagnose, prevent and treat fungal infections [6]. Practicing physicians approach this uncertainty by treating suspected infections empirically. However, researchers that conduct clinical trials tend

and reproduction in any medium, provided the original work is properly cited.

© 2013 Crazzolara et al.; licensee InTech. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

© 2013 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution,

Roman Crazzolara, Adrian Kneer,

threatening sequelae and mortality [1].

immunocompromised patients without fungal infection [5].

http://dx.doi.org/10.5772/54990

**1. Introduction**

Bernhard Meister and Gabriele Kropshofer

Additional information is available at the end of the chapter

## **Invasive Fungal Infections in ALL Patients**

Roman Crazzolara, Adrian Kneer, Bernhard Meister and Gabriele Kropshofer

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/54990

## **1. Introduction**

The success rate of acute lymphoblastic leukemia (ALL) therapy has gradually increased over the past decades. With more than 80% long-term survivors, treatment of ALL in children is undoubtedly one of the great success stories of innovative study-controlled modern medicine [1]. Attempts to boost cure rates for those who do not respond to therapy or relapse with more intense chemotherapy including allogeneic hematopoietic stem cell transplantation have further improved the outcome of patients, particularly for prognostic unfavorable subgroups [2]. However, intensification of treatment can substantially increase morbidity, the risk for lifethreatening sequelae and mortality [1].

Several studies address this important issue and report on the emergence of fungi. A retro‐ spective review of ~ 5.600 patients who underwent hematopoietic stem cell transplantation at the Fred Hutchinson Cancer Research Center (Seattle) from 1985 to 1999 reports a constant increase of 3.5% in the one-year cumulative incidence of probable and proven invasive fungal infections [3]. Investigation of autopsies, skin, and lung biopsies, and bronchoalveolar lavage fluid analyses reveal that non-fumigatus Aspergillus species, such as Fusarium and Zygomy‐ cetes have increased, especially in patients, who have received multiple transplants. These observations are particular worrisome given the increasing importance of amphothericin-B resistant organisms, resulting in a very poor one-year survival rate of ~ 20% [4]. For those who do survive, length of hospital stay and total hospital charges are increased, compared with immunocompromised patients without fungal infection [5].

Despite much effort has been taken to improve therapeutic treatments and strategies, there still remains much uncertainty and controversy regarding the best method to diagnose, prevent and treat fungal infections [6]. Practicing physicians approach this uncertainty by treating suspected infections empirically. However, researchers that conduct clinical trials tend

© 2013 Crazzolara et al.; licensee InTech. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2013 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

to accept only cases in which the diagnosis is certain in order to improve clarity and uniformity of clinical trials. Therefore, members of the European Organization for Research and Treatment of Cancer / Invasive Fungal Infection Study Group (EORTC) and the National Institute of Allergy and Infectious Disease (NIAID) Mycoses Study Group (MSG) formed a consensus study group to define standard definitions of invasive fungal infections for clinical research [7]. Practice guidelines are intended to limit practice variations towards movements such as evidence-based medicine and are primarily suggested by the European Conference of Infections in Leukemia (ECIL; http://www.ebmt.org/Contents/Resources/Library/ ECIL/ Pages/ECIL.aspx). For the clinical purpose there is still a need to develop more effective prevention and treatment strategies. Such strategies may rely on newer antifungal agents that are active against amphothericin B resistant moulds and are well tolerated. Because of limited number of affected patients, multicenter collaborative trials are required.

On the thirtieth day of induction chemotherapy the patient developed fever of 39.2°C. Physical examination was unremarkable. The laboratory tests showed leucopenia (0.5 x

**Prophylaxis Empiric>>Preemptive Targeted**

**Figure 1.** Time course of diagnosis and treatment of fungal infection in a Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ALL) patient. Fungal infection was suspected by a chest X-ray on day thirty four of induc‐ tion chemotherapy for Ph+ ALL. Prophylactic treatment with Fluconazole was switched to pre-emptive therapy with liposomal Amphothericin. Five days later histology of the fungal mass obtained by computed tomography (CT)-guided percutaneous biopsy confirmed the diagnosis of invasive mould infection. Culture revealed Aspergillus flavus, suscep‐

Empirical antibiotic regimen was initiated with a carbapenem (Meropenem) and an amino‐ glycoside (Gentamycin). Because of relapsing fever four days after the initiation of antibiotics,

A chest X-ray showed a distinctive and peculiar mass in the middle of the right lung. Because the radiological image was ambiguous the diagnostics were extended by a chest CT scan, which showed a large mass in the right upper lobe, surrounded by a wide zone of groundglass attenuation demonstrating the halo sign. On the ground of the radiologic examinations, fungal infection was suspicioned and pre-emptive antifungal therapy was initiated. Flucona‐ zole, included in the treatment as a prophylactive measure, was replaced by liposomal Amphothericin administered at a dose of three mg/kg once daily. On the next day CT-guided biopsy was planned to obtain a definitive diagnosis. Biopsy was performed with only a single puncture using a 20 G cutting needle. No pneumothorax or hemorrhage was noted after the procedure. Histological examination yielded dichotomously branching septated hyphae consistent with Aspergillus species, confirming the diagnosis of invasive fungal infection. Culture demonstrated a growth of Aspergillus flavus. Antifungal susceptibility testing with

vancomycin was added. Both blood and urine cultures were aseptic.

**Chest X‐ray**

0 + 48 

tible to Voriconazole.

/L) with an absolute neutrophilic count of 19/μL, but no elevation of inflammatory

+ 52 d + 54 days 

**Chest CT scan**

**Biopsy, Microscopy, Culture**

Invasive Fungal Infections in ALL Patients http://dx.doi.org/10.5772/54990 319

109

proteins (CRP <0.06 mg/dL).

This case-based review examines the current literature to explore basic concepts on epidemi‐ ology, diagnosis and treatment of invasive fungal infections in ALL patients. A case report will be used to illustrate these specific issues.

## **2. Methods**

A systematic review of the literature for an explicit identification of major problems related to the heterogeneity of patients with acute lymphoblastic leukemia who have invasive fungal infections was undertaken. *Pneumocystis* infections were not considered. In brief, the abstracts of 711 articles published from 1985 through 2012 were screened. Of these, 41 articles were finally selected because these report clinical research on patients with ALL who also had deeptissue fungal infections. The minimum diagnostic criteria used to include patients in the study were extracted from definitions devised by the investigators. Likewise, the criteria used to express different degrees of diagnostic probability were summarized, as were the terms most often used to express these levels of uncertainty.

### **3. Case study: A sixteen-year old patient with Ph+ ALL**

A sixteen-year old adolescent was referred to the outpatient oncologic clinic with suspicion of a proliferative disease of the hematopoietic system. Two weeks prior the admission, the patient suffered from sub febrile temperatures and fatigue. At the time of the visit to the general physician scarlet was ruled out and the patient discharged. At admission, the patient's general condition was slightly deteriorated; his physical examination revealed petechial rash over the extremities, pallor and hepatosplenomegaly. Laboratory findings showed ALL with a positive BCR/ABL result and an absolute count of 398.000 blasts per μL. He was subjected to treatment with the ALL BFM 2000 program for high-risk patients. He responded well to chemotherapy and achieved complete morphological remission on day ten of treatment. Following day fifteen, the tyrosine-kinase inhibitor Imatinib Mesylate was added to the standard treatment.

On the thirtieth day of induction chemotherapy the patient developed fever of 39.2°C. Physical examination was unremarkable. The laboratory tests showed leucopenia (0.5 x 109 /L) with an absolute neutrophilic count of 19/μL, but no elevation of inflammatory proteins (CRP <0.06 mg/dL).

to accept only cases in which the diagnosis is certain in order to improve clarity and uniformity of clinical trials. Therefore, members of the European Organization for Research and Treatment of Cancer / Invasive Fungal Infection Study Group (EORTC) and the National Institute of Allergy and Infectious Disease (NIAID) Mycoses Study Group (MSG) formed a consensus study group to define standard definitions of invasive fungal infections for clinical research [7]. Practice guidelines are intended to limit practice variations towards movements such as evidence-based medicine and are primarily suggested by the European Conference of Infections in Leukemia (ECIL; http://www.ebmt.org/Contents/Resources/Library/ ECIL/ Pages/ECIL.aspx). For the clinical purpose there is still a need to develop more effective prevention and treatment strategies. Such strategies may rely on newer antifungal agents that are active against amphothericin B resistant moulds and are well tolerated. Because of limited

This case-based review examines the current literature to explore basic concepts on epidemi‐ ology, diagnosis and treatment of invasive fungal infections in ALL patients. A case report will

A systematic review of the literature for an explicit identification of major problems related to the heterogeneity of patients with acute lymphoblastic leukemia who have invasive fungal infections was undertaken. *Pneumocystis* infections were not considered. In brief, the abstracts of 711 articles published from 1985 through 2012 were screened. Of these, 41 articles were finally selected because these report clinical research on patients with ALL who also had deeptissue fungal infections. The minimum diagnostic criteria used to include patients in the study were extracted from definitions devised by the investigators. Likewise, the criteria used to express different degrees of diagnostic probability were summarized, as were the terms most

A sixteen-year old adolescent was referred to the outpatient oncologic clinic with suspicion of a proliferative disease of the hematopoietic system. Two weeks prior the admission, the patient suffered from sub febrile temperatures and fatigue. At the time of the visit to the general physician scarlet was ruled out and the patient discharged. At admission, the patient's general condition was slightly deteriorated; his physical examination revealed petechial rash over the extremities, pallor and hepatosplenomegaly. Laboratory findings showed ALL with a positive BCR/ABL result and an absolute count of 398.000 blasts per μL. He was subjected to treatment with the ALL BFM 2000 program for high-risk patients. He responded well to chemotherapy and achieved complete morphological remission on day ten of treatment. Following day fifteen, the tyrosine-kinase inhibitor Imatinib Mesylate was added to the standard treatment.

number of affected patients, multicenter collaborative trials are required.

318 Clinical Epidemiology of Acute Lymphoblastic Leukemia - From the Molecules to the Clinic

be used to illustrate these specific issues.

often used to express these levels of uncertainty.

**3. Case study: A sixteen-year old patient with Ph+ ALL**

**2. Methods**

**Figure 1.** Time course of diagnosis and treatment of fungal infection in a Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ALL) patient. Fungal infection was suspected by a chest X-ray on day thirty four of induc‐ tion chemotherapy for Ph+ ALL. Prophylactic treatment with Fluconazole was switched to pre-emptive therapy with liposomal Amphothericin. Five days later histology of the fungal mass obtained by computed tomography (CT)-guided percutaneous biopsy confirmed the diagnosis of invasive mould infection. Culture revealed Aspergillus flavus, suscep‐ tible to Voriconazole.

Empirical antibiotic regimen was initiated with a carbapenem (Meropenem) and an amino‐ glycoside (Gentamycin). Because of relapsing fever four days after the initiation of antibiotics, vancomycin was added. Both blood and urine cultures were aseptic.

A chest X-ray showed a distinctive and peculiar mass in the middle of the right lung. Because the radiological image was ambiguous the diagnostics were extended by a chest CT scan, which showed a large mass in the right upper lobe, surrounded by a wide zone of groundglass attenuation demonstrating the halo sign. On the ground of the radiologic examinations, fungal infection was suspicioned and pre-emptive antifungal therapy was initiated. Flucona‐ zole, included in the treatment as a prophylactive measure, was replaced by liposomal Amphothericin administered at a dose of three mg/kg once daily. On the next day CT-guided biopsy was planned to obtain a definitive diagnosis. Biopsy was performed with only a single puncture using a 20 G cutting needle. No pneumothorax or hemorrhage was noted after the procedure. Histological examination yielded dichotomously branching septated hyphae consistent with Aspergillus species, confirming the diagnosis of invasive fungal infection. Culture demonstrated a growth of Aspergillus flavus. Antifungal susceptibility testing with the agar-based MIC test showed good activity for Voriconazole, Posaconazole and Caspofun‐ gin, but high MIC90 for liposomal Amphothericin.

as Zygomycetes and Fusarium species, have progressively been noted; interestingly, frequency varies by geographical location[8]. Another trend in changing the face of epidemiology is that infections caused by non-albicans Candida species (e.g. Candida

A schematic classification depending on phylogenetic properties of fungal pathogens encountered in ALL patients is presented.

Yeast like pathogens enter the body via the gut or skin and mostly follow the pattern of fungemia and disseminated infection known from Candida species. Rarely the central nervous system, cardiovascular system or other tissues represent sites of

**Hyaline Moulds**

*Candida species, Cryptococcus neoformans, Trichosporon, Blastoschizomyces, .......*

**Yeasts**

**Dermatophytes**

**Dimorphic Moulds**

Invasive Fungal Infections in ALL Patients http://dx.doi.org/10.5772/54990 321

*Histoplasma, Coccidioides, Blastomyces, ....*

*Microsporum, Trichophyton, ....*

Besides invasive infections of the skin and subcutaneous tissues, moulds involve, as airborne pathogens, the sino-pulmonary tract; the emerging opportunistic moulds have a higher propensity for dissemination, in particular into the central nervous system. Because of the lack of specific clinical, radiographic and histological features and the absence of diagnostic surrogate markers in

In general, diagnostic testing should begin with non-invasive methods and only approach invasive steps if needed. Diagnostic options include conventional or high-resolution CT (this has less radiation exposure and was performed in this case report), positron emission tomography (PET), magnetic resonance imaging (MRI), GM assay, 1,3-ß-D-Glucan test, Polymerase chain reaction (PCR), bronchoalveolar lavage, blood culture and tissue biopsy. At this time, MRI and PET are more research-oriented than commonly used clinical approaches. The utility of standard blood cultures is limited because of a high percentage of falsenegative results, particularly in patients with disseminated aspergillosis. Of the listed options, the GM and 1,3-ß-D-Glucan serum

blood, the diagnosis depends on the identification of the organism by means of culture based methods[12].

glabrata, C. krusei, C. tropicalis, C. parapsilosis) have steadily increased, particularly in patients with ALL [11].

**Fungal pathogens**

**Septated Hyphae**

**Hyaline septated Moulds**

*Aspergillus species, Fusarium, Trichoderma, ....*

Figure 2. Pathogenic fungi that cause disease in acute lymphoblastic leukemia (ALL) Patients.

tion depending on phylogenetic properties of fungal pathogens encountered in ALL patients is presented.

system, cardiovascular system or other tissues represent sites of dissemination [12].

**Figure 2.** Pathogenic fungi that cause disease in acute lymphoblastic leukemia (ALL) Patients. A schematic classifica‐

Yeast like pathogens enter the body via the gut or skin and mostly follow the pattern of fungemia and disseminated infection known from Candida species. Rarely the central nervous

Besides invasive infections of the skin and subcutaneous tissues, moulds involve, as airborne pathogens, the sino-pulmonary tract; the emerging opportunistic moulds have a higher propensity for dissemination, in particular into the central nervous system. Because of the lack of specific clinical, radiographic and histological features and the absence of diagnostic surrogate markers in blood, the diagnosis depends on the identification of the organism by

In general, diagnostic testing should begin with non-invasive methods and only approach invasive steps if needed. Diagnostic options include conventional or high-resolution CT (this has less radiation exposure and was performed in this case report), positron emission tomog‐ raphy (PET), magnetic resonance imaging (MRI), GM assay, 1,3-ß-D-Glucan test, Polymerase chain reaction (PCR), bronchoalveolar lavage, blood culture and tissue biopsy. At this time,

**Moulds**

**Dematiaceus Moulds**

*Bipolaris, Cladophialophora, ...*

dissemination[12].

**Aseptated Hyphae**

**Zygomycetes**

**Mucorales** *Rhizopus, Mucor Rhizomucor, ........* **Entomophthorales**

**5. Diagnostics** 

means of culture based methods [12].

**5. Diagnostics**

assay, PCR and the CT scan will be described in detail.

Accordingly antifungal therapy was switched to Voriconazole (6 mg/kg) for eight weeks intravenously and then orally until the twelfth week. CT imaging studies that followed confirmed a gradual recession of the lesion. The patient underwent right sided thoracotomy with wedge resection of the fungal mass. Histopathology revealed Aspergilloma with surrounding chronic granulomatous inflammation, fibrosis and sheets of macrophages. Postoperative course was uneventful and no recurrence of fungal infection over twenty four months follow up was observed. He underwent allogeneic hematopoietic stem cell transplan‐ tation and has been in complete molecular remission since.

## **4. Epidemiology**

Worldwide surveys evaluating the epidemiology of invasive fungal infections have been conducted in large center studies in North America [8]. In European countries data is most commonly derived from single-center reports or regional reports from single countries [8]. Though local epidemiology is a cornerstone of clinical decision making, efforts are now undertaken worldwide to start multi-national surveys on fungal infections in order to improve uniformity of clinical trials.

Until 2 decades ago, infections by Candida were the most common fungal pathogen in patients treated for ALL. However, with the introduction of Fluconazole as primary antifungal prophylaxis and the application of more aggressive treatment protocols, including allogeneic hematopoietic stem cell transplantation, a notable shift towards the advent of invasive aspergillosis has been noted [9]. Whereas almost all of the fungal infections were attributable to candidiasis (11/11) in autopsy studies of the late seventies, mould infections were respon‐ sible for 62% of IFIs (16/26) two decades later [9]. Concordantly, a large multi-centre report from the SEIFEM-2004 study (Sorveglianza Epidemiologica Infezioni Fungine nelle Emopatie Maligne) confirms this trend, indicating, that over half of all fungal infections (346/538) were caused by moulds, in most cases Aspergillus species (310/346) [10]. Most importantly, such infections have become a prime cause of death in patients with hematologic malignancies. The IFI-attributable mortality rate was 39% (209/538). The highest IFI-attributable mortality rates were associated with zygomycosis (64%) followed by fusariosis (53%), aspergillosis (42%), and candidemia (33%) [10].

Along with the increased incidence of mould infections caused by Aspergillus species, other emerging mould opportunistics, such as Zygomycetes and Fusarium species, have progres‐ sively been noted; interestingly, frequency varies by geographical location [8]. Another trend in changing the face of epidemiology is that infections caused by non-albicans Candida species (e.g. Candida glabrata, C. krusei, C. tropicalis, C. parapsilosis) have steadily increased, particularly in patients with ALL [11].

Another trend in changing the face of epidemiology is that infections caused by non-albicans Candida species (e.g. Candida

glabrata, C. krusei, C. tropicalis, C. parapsilosis) have steadily increased, particularly in patients with ALL [11].

Figure 2. Pathogenic fungi that cause disease in acute lymphoblastic leukemia (ALL) Patients. A schematic classification depending on phylogenetic properties of fungal pathogens encountered in ALL patients is presented. **Figure 2.** Pathogenic fungi that cause disease in acute lymphoblastic leukemia (ALL) Patients. A schematic classifica‐ tion depending on phylogenetic properties of fungal pathogens encountered in ALL patients is presented.

Yeast like pathogens enter the body via the gut or skin and mostly follow the pattern of fungemia and disseminated infection known from Candida species. Rarely the central nervous system, cardiovascular system or other tissues represent sites of dissemination[12]. Yeast like pathogens enter the body via the gut or skin and mostly follow the pattern of fungemia and disseminated infection known from Candida species. Rarely the central nervous system, cardiovascular system or other tissues represent sites of dissemination [12].

Besides invasive infections of the skin and subcutaneous tissues, moulds involve, as airborne pathogens, the sino-pulmonary tract; the emerging opportunistic moulds have a higher propensity for dissemination, in particular into the central nervous system. Because of the lack of specific clinical, radiographic and histological features and the absence of diagnostic surrogate markers in blood, the diagnosis depends on the identification of the organism by means of culture based methods[12]. **5. Diagnostics**  In general, diagnostic testing should begin with non-invasive methods and only approach invasive steps if needed. Diagnostic Besides invasive infections of the skin and subcutaneous tissues, moulds involve, as airborne pathogens, the sino-pulmonary tract; the emerging opportunistic moulds have a higher propensity for dissemination, in particular into the central nervous system. Because of the lack of specific clinical, radiographic and histological features and the absence of diagnostic surrogate markers in blood, the diagnosis depends on the identification of the organism by means of culture based methods [12].

options include conventional or high-resolution CT (this has less radiation exposure and was performed in this case report), positron emission tomography (PET), magnetic resonance imaging (MRI), GM assay, 1,3-ß-D-Glucan test, Polymerase chain

negative results, particularly in patients with disseminated aspergillosis. Of the listed options, the GM and 1,3-ß-D-Glucan serum

#### reaction (PCR), bronchoalveolar lavage, blood culture and tissue biopsy. At this time, MRI and PET are more research-oriented than commonly used clinical approaches. The utility of standard blood cultures is limited because of a high percentage of false-**5. Diagnostics**

the agar-based MIC test showed good activity for Voriconazole, Posaconazole and Caspofun‐

Accordingly antifungal therapy was switched to Voriconazole (6 mg/kg) for eight weeks intravenously and then orally until the twelfth week. CT imaging studies that followed confirmed a gradual recession of the lesion. The patient underwent right sided thoracotomy with wedge resection of the fungal mass. Histopathology revealed Aspergilloma with surrounding chronic granulomatous inflammation, fibrosis and sheets of macrophages. Postoperative course was uneventful and no recurrence of fungal infection over twenty four months follow up was observed. He underwent allogeneic hematopoietic stem cell transplan‐

Worldwide surveys evaluating the epidemiology of invasive fungal infections have been conducted in large center studies in North America [8]. In European countries data is most commonly derived from single-center reports or regional reports from single countries [8]. Though local epidemiology is a cornerstone of clinical decision making, efforts are now undertaken worldwide to start multi-national surveys on fungal infections in order to improve

Until 2 decades ago, infections by Candida were the most common fungal pathogen in patients treated for ALL. However, with the introduction of Fluconazole as primary antifungal prophylaxis and the application of more aggressive treatment protocols, including allogeneic hematopoietic stem cell transplantation, a notable shift towards the advent of invasive aspergillosis has been noted [9]. Whereas almost all of the fungal infections were attributable to candidiasis (11/11) in autopsy studies of the late seventies, mould infections were respon‐ sible for 62% of IFIs (16/26) two decades later [9]. Concordantly, a large multi-centre report from the SEIFEM-2004 study (Sorveglianza Epidemiologica Infezioni Fungine nelle Emopatie Maligne) confirms this trend, indicating, that over half of all fungal infections (346/538) were caused by moulds, in most cases Aspergillus species (310/346) [10]. Most importantly, such infections have become a prime cause of death in patients with hematologic malignancies. The IFI-attributable mortality rate was 39% (209/538). The highest IFI-attributable mortality rates were associated with zygomycosis (64%) followed by fusariosis (53%), aspergillosis (42%), and

Along with the increased incidence of mould infections caused by Aspergillus species, other emerging mould opportunistics, such as Zygomycetes and Fusarium species, have progres‐ sively been noted; interestingly, frequency varies by geographical location [8]. Another trend in changing the face of epidemiology is that infections caused by non-albicans Candida species (e.g. Candida glabrata, C. krusei, C. tropicalis, C. parapsilosis) have steadily increased,

gin, but high MIC90 for liposomal Amphothericin.

tation and has been in complete molecular remission since.

**4. Epidemiology**

uniformity of clinical trials.

candidemia (33%) [10].

particularly in patients with ALL [11].

In general, diagnostic testing should begin with non-invasive methods and only approach invasive steps if needed. Diagnostic options include conventional or high-resolution CT (this has less radiation exposure and was performed in this case report), positron emission tomog‐ raphy (PET), magnetic resonance imaging (MRI), GM assay, 1,3-ß-D-Glucan test, Polymerase chain reaction (PCR), bronchoalveolar lavage, blood culture and tissue biopsy. At this time,

assay, PCR and the CT scan will be described in detail.

MRI and PET are more research-oriented than commonly used clinical approaches. The utility of standard blood cultures is limited because of a high percentage of false-negative results, particularly in patients with disseminated aspergillosis. Of the listed options, the GM and 1,3 ß-D-Glucan serum assay, PCR and the CT scan will be described in detail.

in Europe but which was lowered to 0.5 after review by the FDA. Studies have shown that using an index cutoff for positivity of 0.5 versus greater indices substantially increases sensitivity, with only minimal loss in specificity [15]. Factors, which increase false positivity and influence the specificity of the assay, include a low level of cut-off (<0.5), colonization with Bifidobacterium bifidum in the intestinal flora, which mimics the epitope recognized by the EB-A2 in the enzyme-linked immunosorbent assay kit [16] and invasive infections with other fungi, such as Penicillium spp., histoplasmosis, and blastomycosis [13]. Moreover, crossreactivity of the assay has been shown with the use of piperacillin/ tazobactam or amoxicillin/ clavulanate antibiotic therapy and in infants with the nutrition of milk-based formulas [17]. The IDSA guidelines currently recommend using the GM EIA in conjunction with CT scans for early, noninvasive diagnosis of invasive aspergillosis in high-risk patients [13]. The test should be performed serially, at least twice per week through the periods of highest risk,

Invasive Fungal Infections in ALL Patients http://dx.doi.org/10.5772/54990 323

When GM in serum is used for screening for invasive mold infection in children with hema‐ tological malignancies/undergoing HSCT, data should be interpreted with caution, since the assay has a number of limitations in the sensitivity and specificity profile. Prospective monitoring of GM in serum every three to four days in children at high risk for IFD is reason‐ able for early diagnosis of invasive aspergillosis. Although the optimal cut-off value of GM in the serum of children is not well defined, published data support the use of a threshold of an optical density index 0.5 (http://www.ebmt.org/Contents/Resources/Library/ ECIL/Pages/

1,3-ß-D Glucan (BG) is a fungal cell wall component circulating in the blood of patients with invasive aspergillosis, candidemia, but also Fusarium*,* Trichosporum, Saccharomyces, and Pneumocystis jirovecii. Moreover, BG is also detected in patients with infections due to bacteria such as Streptococcus pneumoniae, Pseudomonas aeruginosa and in healthy individuals. However, BG is absent in patients with cryptococcosis and zygomycosis [18]. Antibiotics such as cefepime, piperacillin/tazobactam or meropenem may cause positive BG levels. Investiga‐ tions using different BG assays in 2979 patients (594 with proven or probable IFI) have reported a pooled sensitivity of 76.8% and specificity of 85.3% [19]. Differences in study design (popu‐ lation studies versus case-control, variation in the number of proven or probable IFIs, propor‐ tions of patients with candidemia and aspergillosis, case-mix of neutropenic and nonneutropenic patients, and previous antifungal prophylaxis) highlight the need for further investigations. In children, data is very limited: elevated levels of BG were reported in a casecontrol study of only four children with IFI (3 patients with candidemia, one patient probable

The Fungitell assay (Associates of Cape Cod) for detection of 1,3-ß-D Glucan is approved by the FDA for the diagnosis of invasive mycoses, including aspergillosis [13] and is included as mycological criterion in the revised definitions of invasive fungal disease from the EORTC/MSG consensus group [6]. Unfortunately, there is no recommendation from ECIL or IDSA for clinical practice. However, BG testing in adults is considered as having good

whether the periods involve neutropenia or active GVHD [13].

ECIL.aspx).

**5.2. 1,3-ß-D Glucan**

aspergillosis) [20].

Figure 3. Simplified view of antifungal strategy in acute lymphoblastic leukemia (ALL) patients. Clinical practice (not EORTC criteria) in the management of IFIs depends on the population at risk (e.g. genetics, clinical), availability/value of diagnostic tests and availability/effectiveness of antifungal drugs. HR-ALL: high risk – acute lymphoblastic leukemia; SCT: stem cell transplantation; GM: Galactomannan; CT: computed tomography. **Figure 3.** Simplified view of antifungal strategy in acute lymphoblastic leukemia (ALL) patients. Clinical practice (not EORTC criteria) in the management of IFIs depends on the population at risk (e.g. genetics, clinical), availability/value of diagnostic tests and availability/effectiveness of antifungal drugs. HR-ALL: high risk – acute lymphoblastic leukemia; SCT: stem cell transplantation; GM: Galactomannan; CT: computed tomography.

#### **6. Galactomannan (GM) 5.1. Galactomannan (GM)**

ECIL/Pages/ECIL.aspx).

**7. 1,3-ß-D Glucan** 

GM testing with the Platelia Aspergillus Enzyme Immunoassay (EIA; Biorad Laboratories, Redmond, WA) has been approved by the U.S. Food and Drug Administration (FDA) for Aspergillus diagnostics and is included as a mycological criterion in the revised definitions of invasive fungal disease from the EORTC/MSG consensus group[6]. The test is based on detection of a component of the Aspergillus cell wall, Galactomannan (GM), which is released in the surrounding environment by growing Aspergillus species. Concentration of serum GM correlates with fungal burden in animals with experimental pulmonary aspergillosis – and, according to the 2011 ECIL clinical practice guidelines may be considered as surrogate marker for detection of invasive aspergillosis (http://www.ebmt.org/Contents/Resources/Library/ ECIL/Pages/ECIL.aspx). Recent data suggest that sequential measuring of GM serum levels may be used for therapeutic monitoring in children and adults with pulmonary aspergillosis. The guidelines from the Infections Disease Society of America (IDSA) state, that duration of antifungal therapy must not only rely on disappearance of GM levels, but also on resolution of clinical and radiological findings[13]. The GM EIA has been most studied in hematologic malignancy and bone marrow transplantation populations. Both the specificity and sensitivity of the GM EIA for invasive aspergillosis are high for infected, neutropenic adult patients from these populations. Comparison of 5 studies which use EORTC/MSG criteria and give adequate information for individual patients with results of a formal meta-analysis, indicate sensitivity, specificity of 76% to 73%, 86% to 90% in children and adults respectively[14]. Controversy of GM testing exists about the interpretation of the assay cutoff level (0.5, 1.0), which was originally set at 1.5 and was applied in Europe but which was lowered to 0.5 after review by the FDA. Studies have shown that using an index cutoff for positivity of 0.5 versus greater indices substantially increases sensitivity, with only minimal loss in specificity[15]. Factors, which GM testing with the Platelia Aspergillus Enzyme Immunoassay (EIA; Biorad Laboratories, Redmond, WA) has been approved by the U.S. Food and Drug Administration (FDA) for Aspergillus diagnostics and is included as a mycological criterion in the revised definitions of invasive fungal disease from the EORTC/MSG consensus group [6]. The test is based on detection of a component of the Aspergillus cell wall, Galactomannan (GM), which is released in the surrounding environment by growing Aspergillus species. Concentration of serum GM correlates with fungal burden in animals with experimental pulmonary aspergillosis – and, according to the 2011 ECIL clinical practice guidelines may be considered as surrogate marker for detection of invasive aspergillosis (http://www.ebmt.org/Contents/Resources/Library/ ECIL/Pages/ECIL.aspx). Recent data suggest that sequential measuring of GM serum levels may be used for therapeutic monitoring in children and adults with pulmonary aspergillosis. The guidelines from the Infections Disease Society of America (IDSA) state, that duration of antifungal therapy must not only rely on disappearance of GM levels, but also on resolution of clinical and radiological findings [13].

Bifidobacterium bifidum in the intestinal flora, which mimics the epitope recognized by the EB-A2 in the enzyme-linked immunosorbent assay kit[16] and invasive infections with other fungi, such as Penicillium spp., histoplasmosis, and blastomycosis[13]. Moreover, cross-reactivity of the assay has been shown with the use of piperacillin/ tazobactam or amoxicillin/clavulanate antibiotic therapy and in infants with the nutrition of milk-based formulas[17]. The IDSA guidelines currently recommend using the GM EIA in conjunction with CT scans for early, noninvasive diagnosis of invasive aspergillosis in high-risk patients[13]. The test should be performed serially, at least twice per week through the periods of highest risk, whether the periods involve neutropenia or active GVHD[13]. The GM EIA has been most studied in hematologic malignancy and bone marrow transplan‐ tation populations. Both the specificity and sensitivity of the GM EIA for invasive aspergillosis are high for infected, neutropenic adult patients from these populations. Comparison of 5 studies which use EORTC/MSG criteria and give adequate information for individual patients with results of a formal meta-analysis, indicate sensitivity, specificity of 76% to 73%, 86% to 90% in children and adults respectively [14]. Controversy of GM testing exists about the interpretation of the assay cutoff level (0.5, 1.0), which was originally set at 1.5 and was applied

increase false positivity and influence the specificity of the assay, include a low level of cut-off (<0.5), colonization with

When GM in serum is used for screening for invasive mold infection in children with hematological malignancies/undergoing HSCT, data should be interpreted with caution, since the assay has a number of limitations in the sensitivity and specificity profile. Prospective monitoring of GM in serum every three to four days in children at high risk for IFD is reasonable for early diagnosis of invasive aspergillosis. Although the optimal cut-off value of GM in the serum of children is not well defined, published data support the use of a threshold of an optical density index 0.5 (http://www.ebmt.org/Contents/Resources/Library/

1,3-ß-D Glucan (BG) is a fungal cell wall component circulating in the blood of patients with invasive aspergillosis, candidemia, but also Fusarium*,* Trichosporum, Saccharomyces, and Pneumocystis jirovecii. Moreover, BG is also detected in patients with infections due to bacteria such as Streptococcus pneumoniae, Pseudomonas aeruginosa and in healthy individuals. However, BG is absent in patients with cryptococcosis and zygomycosis[18]. Antibiotics such as cefepime, piperacillin/tazobactam or meropenem may cause in Europe but which was lowered to 0.5 after review by the FDA. Studies have shown that using an index cutoff for positivity of 0.5 versus greater indices substantially increases sensitivity, with only minimal loss in specificity [15]. Factors, which increase false positivity and influence the specificity of the assay, include a low level of cut-off (<0.5), colonization with Bifidobacterium bifidum in the intestinal flora, which mimics the epitope recognized by the EB-A2 in the enzyme-linked immunosorbent assay kit [16] and invasive infections with other fungi, such as Penicillium spp., histoplasmosis, and blastomycosis [13]. Moreover, crossreactivity of the assay has been shown with the use of piperacillin/ tazobactam or amoxicillin/ clavulanate antibiotic therapy and in infants with the nutrition of milk-based formulas [17].

The IDSA guidelines currently recommend using the GM EIA in conjunction with CT scans for early, noninvasive diagnosis of invasive aspergillosis in high-risk patients [13]. The test should be performed serially, at least twice per week through the periods of highest risk, whether the periods involve neutropenia or active GVHD [13].

When GM in serum is used for screening for invasive mold infection in children with hema‐ tological malignancies/undergoing HSCT, data should be interpreted with caution, since the assay has a number of limitations in the sensitivity and specificity profile. Prospective monitoring of GM in serum every three to four days in children at high risk for IFD is reason‐ able for early diagnosis of invasive aspergillosis. Although the optimal cut-off value of GM in the serum of children is not well defined, published data support the use of a threshold of an optical density index 0.5 (http://www.ebmt.org/Contents/Resources/Library/ ECIL/Pages/ ECIL.aspx).

#### **5.2. 1,3-ß-D Glucan**

MRI and PET are more research-oriented than commonly used clinical approaches. The utility of standard blood cultures is limited because of a high percentage of false-negative results, particularly in patients with disseminated aspergillosis. Of the listed options, the GM and 1,3-

> • GM • 1,3-ß-D-Glucan • CT scan **PRE-EMPTIVE**

Figure 3. Simplified view of antifungal strategy in acute lymphoblastic leukemia (ALL) patients.

**Figure 3.** Simplified view of antifungal strategy in acute lymphoblastic leukemia (ALL) patients. Clinical practice (not EORTC criteria) in the management of IFIs depends on the population at risk (e.g. genetics, clinical), availability/value of diagnostic tests and availability/effectiveness of antifungal drugs. HR-ALL: high risk – acute lymphoblastic leukemia;

levels, but also on resolution of clinical and radiological findings[13].

highest risk, whether the periods involve neutropenia or active GVHD[13].

leukemia; SCT: stem cell transplantation; GM: Galactomannan; CT: computed tomography.

GM testing with the Platelia Aspergillus Enzyme Immunoassay (EIA; Biorad Laboratories, Redmond, WA) has been approved by the U.S. Food and Drug Administration (FDA) for Aspergillus diagnostics and is included as a mycological criterion in the revised definitions of invasive fungal disease from the EORTC/MSG consensus group [6]. The test is based on detection of a component of the Aspergillus cell wall, Galactomannan (GM), which is released in the surrounding environment by growing Aspergillus species. Concentration of serum GM correlates with fungal burden in animals with experimental pulmonary aspergillosis – and, according to the 2011 ECIL clinical practice guidelines may be considered as surrogate marker for detection of invasive aspergillosis (http://www.ebmt.org/Contents/Resources/Library/ ECIL/Pages/ECIL.aspx). Recent data suggest that sequential measuring of GM serum levels may be used for therapeutic monitoring in children and adults with pulmonary aspergillosis. The guidelines from the Infections Disease Society of America (IDSA) state, that duration of antifungal therapy must not only rely on disappearance of GM levels, but also on resolution

Clinical practice (not EORTC criteria) in the management of IFIs depends on the population at risk (e.g. genetics, clinical), availability/value of diagnostic tests and availability/effectiveness of antifungal drugs. HR-ALL: high risk – acute lymphoblastic

• Biopsy/Blood sample • Histology/ Culture

**TARGETED**

GM testing with the Platelia Aspergillus Enzyme Immunoassay (EIA; Biorad Laboratories, Redmond, WA) has been approved by the U.S. Food and Drug Administration (FDA) for Aspergillus diagnostics and is included as a mycological criterion in the revised definitions of invasive fungal disease from the EORTC/MSG consensus group[6]. The test is based on detection of a component of the Aspergillus cell wall, Galactomannan (GM), which is released in the surrounding environment by growing Aspergillus species. Concentration of serum GM correlates with fungal burden in animals with experimental pulmonary aspergillosis – and, according to the 2011 ECIL clinical practice guidelines may be considered as surrogate marker for detection of invasive aspergillosis (http://www.ebmt.org/Contents/Resources/Library/ ECIL/Pages/ECIL.aspx). Recent data suggest that sequential measuring of GM serum levels may be used for therapeutic monitoring in children and adults with pulmonary aspergillosis. The guidelines from the Infections Disease Society of America (IDSA) state, that duration of antifungal therapy must not only rely on disappearance of GM

The GM EIA has been most studied in hematologic malignancy and bone marrow transplantation populations. Both the specificity and sensitivity of the GM EIA for invasive aspergillosis are high for infected, neutropenic adult patients from these populations. Comparison of 5 studies which use EORTC/MSG criteria and give adequate information for individual patients with results of a formal meta-analysis, indicate sensitivity, specificity of 76% to 73%, 86% to 90% in children and adults respectively[14]. Controversy of GM testing exists about the interpretation of the assay cutoff level (0.5, 1.0), which was originally set at 1.5 and was applied in Europe but which was lowered to 0.5 after review by the FDA. Studies have shown that using an index cutoff for positivity of 0.5 versus greater indices substantially increases sensitivity, with only minimal loss in specificity[15]. Factors, which increase false positivity and influence the specificity of the assay, include a low level of cut-off (<0.5), colonization with Bifidobacterium bifidum in the intestinal flora, which mimics the epitope recognized by the EB-A2 in the enzyme-linked immunosorbent assay kit[16] and invasive infections with other fungi, such as Penicillium spp., histoplasmosis, and blastomycosis[13]. Moreover, cross-reactivity of the assay has been shown with the use of piperacillin/ tazobactam or

The IDSA guidelines currently recommend using the GM EIA in conjunction with CT scans for early, noninvasive diagnosis of invasive aspergillosis in high-risk patients[13]. The test should be performed serially, at least twice per week through the periods of

When GM in serum is used for screening for invasive mold infection in children with hematological malignancies/undergoing HSCT, data should be interpreted with caution, since the assay has a number of limitations in the sensitivity and specificity profile. Prospective monitoring of GM in serum every three to four days in children at high risk for IFD is reasonable for early diagnosis of invasive aspergillosis. Although the optimal cut-off value of GM in the serum of children is not well defined, published data support the use of a threshold of an optical density index 0.5 (http://www.ebmt.org/Contents/Resources/Library/

1,3-ß-D Glucan (BG) is a fungal cell wall component circulating in the blood of patients with invasive aspergillosis, candidemia, but also Fusarium*,* Trichosporum, Saccharomyces, and Pneumocystis jirovecii. Moreover, BG is also detected in patients with infections due to bacteria such as Streptococcus pneumoniae, Pseudomonas aeruginosa and in healthy individuals. However, BG is absent in patients with cryptococcosis and zygomycosis[18]. Antibiotics such as cefepime, piperacillin/tazobactam or meropenem may cause

amoxicillin/clavulanate antibiotic therapy and in infants with the nutrition of milk-based formulas[17].

The GM EIA has been most studied in hematologic malignancy and bone marrow transplan‐ tation populations. Both the specificity and sensitivity of the GM EIA for invasive aspergillosis are high for infected, neutropenic adult patients from these populations. Comparison of 5 studies which use EORTC/MSG criteria and give adequate information for individual patients with results of a formal meta-analysis, indicate sensitivity, specificity of 76% to 73%, 86% to 90% in children and adults respectively [14]. Controversy of GM testing exists about the interpretation of the assay cutoff level (0.5, 1.0), which was originally set at 1.5 and was applied

ß-D-Glucan serum assay, PCR and the CT scan will be described in detail.

322 Clinical Epidemiology of Acute Lymphoblastic Leukemia - From the Molecules to the Clinic

• Prolonged fever (> 96h)

**EMPIRIC**

**6. Galactomannan (GM)** 

SCT: stem cell transplantation; GM: Galactomannan; CT: computed tomography.

•Risk groups (e.g. HR‐ ALL, SCT) **PROPHYLAXIS**

**5.1. Galactomannan (GM)**

ECIL/Pages/ECIL.aspx).

of clinical and radiological findings [13].

**7. 1,3-ß-D Glucan** 

1,3-ß-D Glucan (BG) is a fungal cell wall component circulating in the blood of patients with invasive aspergillosis, candidemia, but also Fusarium*,* Trichosporum, Saccharomyces, and Pneumocystis jirovecii. Moreover, BG is also detected in patients with infections due to bacteria such as Streptococcus pneumoniae, Pseudomonas aeruginosa and in healthy individuals. However, BG is absent in patients with cryptococcosis and zygomycosis [18]. Antibiotics such as cefepime, piperacillin/tazobactam or meropenem may cause positive BG levels. Investiga‐ tions using different BG assays in 2979 patients (594 with proven or probable IFI) have reported a pooled sensitivity of 76.8% and specificity of 85.3% [19]. Differences in study design (popu‐ lation studies versus case-control, variation in the number of proven or probable IFIs, propor‐ tions of patients with candidemia and aspergillosis, case-mix of neutropenic and nonneutropenic patients, and previous antifungal prophylaxis) highlight the need for further investigations. In children, data is very limited: elevated levels of BG were reported in a casecontrol study of only four children with IFI (3 patients with candidemia, one patient probable aspergillosis) [20].

The Fungitell assay (Associates of Cape Cod) for detection of 1,3-ß-D Glucan is approved by the FDA for the diagnosis of invasive mycoses, including aspergillosis [13] and is included as mycological criterion in the revised definitions of invasive fungal disease from the EORTC/MSG consensus group [6]. Unfortunately, there is no recommendation from ECIL or IDSA for clinical practice. However, BG testing in adults is considered as having good diagnostic accuracy for early diagnosis of IFD; in children, data are too limited to make any recommendations (http://www.ebmt.org/Contents/Resources/Library/ ECIL/Pages/ ECIL.aspx).

lesion size and number in patients with invasive pulmonary aspergillosis [30]. The appearance of cavities on serial CT scans (frequently accompanied by the appearance of the air-crescent sign as neutropenia resolves) may be indicative of patient recovery. Similarly, if antifungal therapy is initiated and subsequent scans show an increase in the number or size of lesions, this is more likely a reflection of the typical progression of disease rather than failed therapy. According to the ECIL recommendations, in high-risk patients with persistent febrile neutro‐ penia that persists beyond 96 hours or with focal clinical findings, imaging studies (e.g., CTscan of the lung or adequate imaging of the symptomatic region) should be performed. Further diagnostic work-up (e.g., BAL, biopsy) should be considered and mold-active antifungal

Invasive Fungal Infections in ALL Patients http://dx.doi.org/10.5772/54990 325

Antifungal strategies include prophylaxis, empiric antifungal therapy, pre-emptive antifungal therapy and treatment of established invasive fungal infection (Figure 3). For individual patient populations, each strategy needs to consider the patients risk, the local epidemiology, the availability of diagnostic tools and the availability and effectiveness of antifungal agents. Last, but not least a cost – benefit analysis (i.e. toxicity, financial aspects) is mandatory. For the purpose of this textbook spectrum, potency, mode of action, and clinical indication of anti‐

Amphotericin deoxycholate (DAMB) and its lipid formulations, including amphotericin B colloidal dispersion (ABCD), amphotericin B lipid complex (ABLC), and liposomal ampho‐ tericin B (LAMB,) have a wide range of activity against most fungal pathogens. Only Asper‐

In comparison to DAMB, nephrotoxicity is rarely seen with the use of the lipid formula‐ tions; infusion-related reactions, such as fever, chills and rigor are substantially less frequent with LAMB. Mild increases in bilirubin and alkaline phosphatase are associated with all three lipid formulations, elevation of transaminases with LAMB only. Currently, DAMB is licensed for neonatal invasive candidiasis and induction therapy for cryptococcal meningi‐ tis; LAMB is approved as first line empirical treatment of suspected invasive aspergillosis and candidiasis; ABCD is licensed for second-line treatment of patients with invasive aspergillosis, and ABLC for second-line treatment of patients with invasive Candida or

The recommended therapeutic dosages are 0.7 to 1.0 mg/kg/day for DAMB, 3–4 mg/kg/day for ABCD, 5 mg/kg/day for ABLC, and 3 (to 5) mg/kg/day for LAMB, respectively. The available evidence does not suggest pharmacokinetic differences of LAMB between adults and

gillus terreus and Fusarium species are less susceptible (Table 1.) [31].

treatment should be initiated.

fungal agents will be discussed.

**6.1. Amphotericin B**

Aspergillus infections [34].

children including preterm and newborn infants [33].

**6. Treatment**

#### **5.3. PCR**

Detection of antifungal DNA has been advocated as a promising, rapid and more sensitive diagnostic tool, but false-positive results can occur, and a standardized commercial method is not yet available. Several PCR assays to detect fungal DNA have been described, but most have shown that the global performance was too low to be of clinical interest. Different situations have been reported: PCR either has high sensitivity and NPV, while specificity and PPV is low, or, conversely, high specificity and PPV with low sensitivity and NPV [21-24]. These discrepancies can be due to the different technical approaches used. Indeed, a major difference is the type of PCR method used in these studies, i.e., nested PCR, PCR–enzymelinked immunosorbent assay, or RT-PCR [22;24]. Also, the superiority of large serum volumes (> 1 ml) in comparison with conventional serum samples (100 μl to 200 μl) has clearly been shown [23]. In view of changing epidemiology a panfungal PCR might be advantageous to permit the detection of a wide range of fungal pathogens. Its sensitivity of 96%, negative predictive values of 98%, whereas the specificity and positive predictive value were 77% and 62%, respectively is far superior to single PCR measurements [25].

In summary, despite ISDA and ECIL do not give any recommendations, combining nonculture based diagnostics is an important research direction that may improve the overall predictive value of these systems [26].

#### **5.4. Chest CT scan**

Systematic chest CT scan allows early diagnosis of invasive pulmonary aspergillosis, is more sensitive and specific than traditional chest radiographs and is a clinical criterion in the revised definitions of invasive fungal disease from the EORTC/MSG consensus group. Characteristic findings consist of nodules surrounded by the 'halo sign', an area of haziness or ground-glass opacity, or pleura-based, wedge-shaped areas of consolidation [27]. These findings correspond to areas of hemorrhagic infarcts. In severely neutropenic patients, the halo sign is highly suggestive of angioinvasive aspergillosis. However, a similar appearance has been described in a number of other conditions, including infections with herpes virus or cytomegalovirus, Kaposi sarcoma, Wegener granulomatosis, and bronchiolitis obliterans organizing pneumonia [12]. The air crescent sign, a crescent-shaped area of radiolucency in a region of nodular opacity, is usually seen during convalescence in angioinvasive aspergillosis (i.e., 2–3 weeks after initiation of treatment and concomitant with resolution of the neutropenia) [28]. Of note, some studies suggest that cavitation and the air-crescent sign are more likely to be observed in adults, and may frequently be absent from CT scans obtained from young children with pulmonary invasive aspergillosis [29]. When obtaining serial CT scans, it is also important to realize that irrespective of antifungal therapy, the pattern is characterized by an initial rise in number and size of lesions, followed by a plateau in lesion size, and gradual reduction [12]. Moreover, is time until complete radiologic remission and outcome independent of initial or maximum lesion size and number in patients with invasive pulmonary aspergillosis [30]. The appearance of cavities on serial CT scans (frequently accompanied by the appearance of the air-crescent sign as neutropenia resolves) may be indicative of patient recovery. Similarly, if antifungal therapy is initiated and subsequent scans show an increase in the number or size of lesions, this is more likely a reflection of the typical progression of disease rather than failed therapy. According to the ECIL recommendations, in high-risk patients with persistent febrile neutro‐ penia that persists beyond 96 hours or with focal clinical findings, imaging studies (e.g., CTscan of the lung or adequate imaging of the symptomatic region) should be performed. Further diagnostic work-up (e.g., BAL, biopsy) should be considered and mold-active antifungal treatment should be initiated.

## **6. Treatment**

diagnostic accuracy for early diagnosis of IFD; in children, data are too limited to make any recommendations (http://www.ebmt.org/Contents/Resources/Library/ ECIL/Pages/

Detection of antifungal DNA has been advocated as a promising, rapid and more sensitive diagnostic tool, but false-positive results can occur, and a standardized commercial method is not yet available. Several PCR assays to detect fungal DNA have been described, but most have shown that the global performance was too low to be of clinical interest. Different situations have been reported: PCR either has high sensitivity and NPV, while specificity and PPV is low, or, conversely, high specificity and PPV with low sensitivity and NPV [21-24]. These discrepancies can be due to the different technical approaches used. Indeed, a major difference is the type of PCR method used in these studies, i.e., nested PCR, PCR–enzymelinked immunosorbent assay, or RT-PCR [22;24]. Also, the superiority of large serum volumes (> 1 ml) in comparison with conventional serum samples (100 μl to 200 μl) has clearly been shown [23]. In view of changing epidemiology a panfungal PCR might be advantageous to permit the detection of a wide range of fungal pathogens. Its sensitivity of 96%, negative predictive values of 98%, whereas the specificity and positive predictive value were 77% and

In summary, despite ISDA and ECIL do not give any recommendations, combining nonculture based diagnostics is an important research direction that may improve the overall

Systematic chest CT scan allows early diagnosis of invasive pulmonary aspergillosis, is more sensitive and specific than traditional chest radiographs and is a clinical criterion in the revised definitions of invasive fungal disease from the EORTC/MSG consensus group. Characteristic findings consist of nodules surrounded by the 'halo sign', an area of haziness or ground-glass opacity, or pleura-based, wedge-shaped areas of consolidation [27]. These findings correspond to areas of hemorrhagic infarcts. In severely neutropenic patients, the halo sign is highly suggestive of angioinvasive aspergillosis. However, a similar appearance has been described in a number of other conditions, including infections with herpes virus or cytomegalovirus, Kaposi sarcoma, Wegener granulomatosis, and bronchiolitis obliterans organizing pneumonia [12]. The air crescent sign, a crescent-shaped area of radiolucency in a region of nodular opacity, is usually seen during convalescence in angioinvasive aspergillosis (i.e., 2–3 weeks after initiation of treatment and concomitant with resolution of the neutropenia) [28]. Of note, some studies suggest that cavitation and the air-crescent sign are more likely to be observed in adults, and may frequently be absent from CT scans obtained from young children with pulmonary invasive aspergillosis [29]. When obtaining serial CT scans, it is also important to realize that irrespective of antifungal therapy, the pattern is characterized by an initial rise in number and size of lesions, followed by a plateau in lesion size, and gradual reduction [12]. Moreover, is time until complete radiologic remission and outcome independent of initial or maximum

62%, respectively is far superior to single PCR measurements [25].

324 Clinical Epidemiology of Acute Lymphoblastic Leukemia - From the Molecules to the Clinic

predictive value of these systems [26].

**5.4. Chest CT scan**

ECIL.aspx).

**5.3. PCR**

Antifungal strategies include prophylaxis, empiric antifungal therapy, pre-emptive antifungal therapy and treatment of established invasive fungal infection (Figure 3). For individual patient populations, each strategy needs to consider the patients risk, the local epidemiology, the availability of diagnostic tools and the availability and effectiveness of antifungal agents. Last, but not least a cost – benefit analysis (i.e. toxicity, financial aspects) is mandatory. For the purpose of this textbook spectrum, potency, mode of action, and clinical indication of anti‐ fungal agents will be discussed.

#### **6.1. Amphotericin B**

Amphotericin deoxycholate (DAMB) and its lipid formulations, including amphotericin B colloidal dispersion (ABCD), amphotericin B lipid complex (ABLC), and liposomal ampho‐ tericin B (LAMB,) have a wide range of activity against most fungal pathogens. Only Asper‐ gillus terreus and Fusarium species are less susceptible (Table 1.) [31].

In comparison to DAMB, nephrotoxicity is rarely seen with the use of the lipid formula‐ tions; infusion-related reactions, such as fever, chills and rigor are substantially less frequent with LAMB. Mild increases in bilirubin and alkaline phosphatase are associated with all three lipid formulations, elevation of transaminases with LAMB only. Currently, DAMB is licensed for neonatal invasive candidiasis and induction therapy for cryptococcal meningi‐ tis; LAMB is approved as first line empirical treatment of suspected invasive aspergillosis and candidiasis; ABCD is licensed for second-line treatment of patients with invasive aspergillosis, and ABLC for second-line treatment of patients with invasive Candida or Aspergillus infections [34].

The recommended therapeutic dosages are 0.7 to 1.0 mg/kg/day for DAMB, 3–4 mg/kg/day for ABCD, 5 mg/kg/day for ABLC, and 3 (to 5) mg/kg/day for LAMB, respectively. The available evidence does not suggest pharmacokinetic differences of LAMB between adults and children including preterm and newborn infants [33].

**Figure 4.** Schematic overview of current antifungal agents in regard to its target. Flucytosine inhibits RNA and DNA synthesis, Triazoles inhibit ergosterol biosynthesis, polyenes bind to sterols in the plasma membrane and echinocan‐ dines inhibit beta [1,3]-D-Glucan-synthesis. LAMB: liposomal Amphotericin B; DAMB: Amphotericin B deoxycholate; ABCD: Amphotericin B colloidal dispersion; ABLC: amphotericin B lipid complex.

#### **6.2. Fluconazole**

Fluconazole has a very narrow fungal susceptibility against Candida species (Candida glabrata and krusei have a high MIC index) and lacks activity against Aspergillus species and zygo‐ mycetes (Table 1.). Fluconazole is not metabolized and mainly renally excreted, and drug levels correlate with strictly with renal function [33]. It is licensed for prophylactic use in patients at risk for IFIs and for targeted treatment of candidiasis. For pediatric patients (they show a more rapid excretion and shorter half-life), the recommended dosage is higher than for adults, 8 to 12 mg/kg/day versus 5 mg/kg/day, respectively [34].

ECIL and IDSA guidelines, Itraconazole should be used as second-line therapy in the preven‐

**Table 1.** Susceptibility of important fungal pathogens against some common antifungal agents.

+ = high activity rate; (+) = little reduced activity rate; -/+ = higher resistant rates in some areas; - = mostly resistant

Voriconazole has similar activity as Itraconazole and is active against most Candida and Aspergillus species, but not zygomycetes, Candida glabrata and C. krusei (Table 1.). The effectiveness of this compound has been demonstrated in large clinical trials in both adults and children, and has led to its approval for empirical and pre-emptive antifungal therapy [31]. Because of its wide use, breakthrough infections with zygomycetes have been reported [37]. Additionally, breakthrough infections with susceptible strains have been noted in patients with low plasma levels, necessitating the monitoring of through plasma levels [38]. In children, Voriconazole is more rapidly metabolized, suggesting a higher dosage of 7-8 mg/kg/b.i.d. than in adults (4-5 mg/kg/b.i.d.) [33]. Relevant side effects of Voriconazole include elevations of liver enzymes, visual disturbances and photosensitivity skin reactions, particularly if com‐ bined with nucleoside analoga, which are commonly used in the treatment of ALL. In addition,

tion of IFIs.

**6.4. Voriconazole**

[11;32;33].C.: Candida; Asp.: Aspergillus; spp.: species.

**Amphothericn B**

**Fluconazole** **Voriconazole**

Candida albicans + (+) + + + + + C. parapsilosis + + + + + +/- +/- C. lusitaniae -/+ + + + + + + C. tropicalis + -/+ + + + + + C. glabrata + - -/+ + -/+ + + C. krusei + - -/+ + -/+ + + Asp. fumigatus + - + + + + + Asp. flavus (+) - + + + + + Asp. terreus - - + + + + + Asp. niger + - (+) + (+) + + Zygomycetes + - - (+) - - - Fusarium spp. (+) - - - - - -

**Posaconazole** **Itraconazole** **Caspofungin**

Invasive Fungal Infections in ALL Patients http://dx.doi.org/10.5772/54990

**Micafungin**

327

#### **6.3. Itraconazole**

The compound is active against most Candida and Aspergillus species, but the susceptibility against Candida glabrata and C. krusei is limited (Table 1). There is no activity against zygomycetes. The pharmacokinetics is characterized by inter-individual variability of gastro‐ intestinal absorption and hepatic metabolism [35]. Accordingly, measurement of drug levels is necessary and results of meta-analysis suggest that the trough plasma level should be higher than 0.5 μg / mL [36]. Concerns have arisen on the interaction with drugs such as vincristine and cyclosporine, which are major components of both induction ALL therapy and prevention of GvHD in ALL transplanted patients. Moreover, 10% of patients experience gastrointestinal adverse effects, such as nausea and diarrhea, which limits its acceptance [34]. According to the


+ = high activity rate; (+) = little reduced activity rate; -/+ = higher resistant rates in some areas; - = mostly resistant [11;32;33].C.: Candida; Asp.: Aspergillus; spp.: species.

**Table 1.** Susceptibility of important fungal pathogens against some common antifungal agents.

ECIL and IDSA guidelines, Itraconazole should be used as second-line therapy in the preven‐ tion of IFIs.

#### **6.4. Voriconazole**

**6.2. Fluconazole**

**6.3. Itraconazole**

12 mg/kg/day versus 5 mg/kg/day, respectively [34].

ABCD: Amphotericin B colloidal dispersion; ABLC: amphotericin B lipid complex.

326 Clinical Epidemiology of Acute Lymphoblastic Leukemia - From the Molecules to the Clinic

**NUCLEIC ACID SYNTHESIS** *Flucytosine*

**TRIAZOLES** *Fluconazole Itraconazole Voriconazole Posaconazole*

Fluconazole has a very narrow fungal susceptibility against Candida species (Candida glabrata and krusei have a high MIC index) and lacks activity against Aspergillus species and zygo‐ mycetes (Table 1.). Fluconazole is not metabolized and mainly renally excreted, and drug levels correlate with strictly with renal function [33]. It is licensed for prophylactic use in patients at risk for IFIs and for targeted treatment of candidiasis. For pediatric patients (they show a more rapid excretion and shorter half-life), the recommended dosage is higher than for adults, 8 to

**Figure 4.** Schematic overview of current antifungal agents in regard to its target. Flucytosine inhibits RNA and DNA synthesis, Triazoles inhibit ergosterol biosynthesis, polyenes bind to sterols in the plasma membrane and echinocan‐ dines inhibit beta [1,3]-D-Glucan-synthesis. LAMB: liposomal Amphotericin B; DAMB: Amphotericin B deoxycholate;

**CELL WALL** Echinocandines: *Anidulafungin Caspofungin Micafungine*

**CELL MEMBRANE** Polyenes: *LAMB DAMB ABLC ABCD*

The compound is active against most Candida and Aspergillus species, but the susceptibility against Candida glabrata and C. krusei is limited (Table 1). There is no activity against zygomycetes. The pharmacokinetics is characterized by inter-individual variability of gastro‐ intestinal absorption and hepatic metabolism [35]. Accordingly, measurement of drug levels is necessary and results of meta-analysis suggest that the trough plasma level should be higher than 0.5 μg / mL [36]. Concerns have arisen on the interaction with drugs such as vincristine and cyclosporine, which are major components of both induction ALL therapy and prevention of GvHD in ALL transplanted patients. Moreover, 10% of patients experience gastrointestinal adverse effects, such as nausea and diarrhea, which limits its acceptance [34]. According to the

Voriconazole has similar activity as Itraconazole and is active against most Candida and Aspergillus species, but not zygomycetes, Candida glabrata and C. krusei (Table 1.). The effectiveness of this compound has been demonstrated in large clinical trials in both adults and children, and has led to its approval for empirical and pre-emptive antifungal therapy [31]. Because of its wide use, breakthrough infections with zygomycetes have been reported [37]. Additionally, breakthrough infections with susceptible strains have been noted in patients with low plasma levels, necessitating the monitoring of through plasma levels [38]. In children, Voriconazole is more rapidly metabolized, suggesting a higher dosage of 7-8 mg/kg/b.i.d. than in adults (4-5 mg/kg/b.i.d.) [33]. Relevant side effects of Voriconazole include elevations of liver enzymes, visual disturbances and photosensitivity skin reactions, particularly if com‐ bined with nucleoside analoga, which are commonly used in the treatment of ALL. In addition, the interaction of Voriconazole with a number of drugs (e.g. Vincristine, Cyclosporine A, and Omeprazole) has to be considered [33].

questions regarding antifungal treatment have to be addressed in future studies, such as the

Invasive Fungal Infections in ALL Patients http://dx.doi.org/10.5772/54990 329

, Adrian Kneer, Bernhard Meister and Gabriele Kropshofer

[1] Pui, C, Relling, M. V, & Downing, J. R. Mechanisms of disease: Acute lymphoblastic

[2] Arico, M, Valsecchi, M. G, Camitta, B, Schrappe, M, Chessells, J, Baruchel, A, et al. Outcome of treatment in children with philadelphia chromosome-positive acute lym‐

[3] Marr, K. A, Carter, R. A, Crippa, F, Wald, A, & Corey, L. Epidemiology and outcome of mould infections in hematopoietic stem cell transplant recipients. Clinical Infec‐

[4] Mcneil, M. M, Nash, S. L, Hajjeh, R. A, Phelan, M. A, Conn, L. A, Plikaytis, B. D, et al. Trends in mortality due to invasive mycotic diseases in the United States, Clinical In‐

[5] Zaoutis, T. E, Heydon, K, Chu, J. H, Walsh, T. J, & Steinbach, W. J. Epidemiology, outcomes, and costs of invasive aspergillosis in immunocompromised children in the

[6] de PBWalsh TJ, Donnelly JP, Stevens DA, Edwards JE, Calandra T et al. Revised defi‐ nitions of invasive fungal disease from the European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycoses Study Group (EORTC/MSG)

phoblastic leukemia. New England Journal of Medicine (2000). , 998-1006.

leukemia. New England Journal of Medicine (2004). , 1535-1548.

duration of treatment or the benefit of costly combination antifungal therapy.

We thank Kinderkrebshilfe Tirol und Vorarlberg for funding.

\*Address all correspondence to: roman.crazzolara@i-med.ac.at

tious Diseases (2002). , 909-917.

fectious Diseases (2001). , 1980-1997.

United States, 2000. Pediatrics (2006). EE716., 711.

Consensus Group. Clin Infect Dis (2008). , 1813-1821.

Department of Pediatrics, Medical University of Innsbruck, Austria

**Acknowledgements**

**Author details**

Roman Crazzolara\*

**References**

#### **6.5. Posaconazole**

This compound has a potent and broad-spectrum activity against most clinically important fungal infections, including zygomycetes, distinguishing it from the other azoles [33]. Accord‐ ing to the ECIL/ IDSA guidelines it is recommended as second-line treatment of aspergillosis, fusariosis, chromoblastomycosis and coccidioidomycosis. In addition, Posaconazole is approved for prophylaxis in high-risk patients older than 13 years of age with ALL and in hematopoietic stem cell transplant patients with graft-versus-host disease [31;39]. The dosage for prophylaxis is 200 mg three times daily, for salvage treatment the dose is increased to 400 mg two times daily. Similar to Voriconazole, interference with cytochrome P450 dependent metabolites (e.g. Cyclosporine) need to be considered [34].

#### **6.6. Caspofungin**

Caspofungin is active against Candida spp. and Aspergillus spp., but resistant against Cryptococcus species and zygomycetes (Table 1.). It is licensed for adult and pediatric patients, including neonates, for empirical antifungal therapy in persistently febrile neutropenic patients, for second-line pre-emptive therapy of suspected aspergillosis and for primary therapy in non-neutropenic patients with invasive Candida infections. The recommended dose regimen in adults consists of a single 70-mg loading dose on day 1, followed by 50 mg daily thereafter [34]. A dosage of 1 mg/kg for children has been suggested [31]. A favorable safety profile has been described, the most common drug-related adverse events were fever, increased ALT, and rash; few events were serious or required treatment discontinuation [40].

#### **6.7. Micafungin**

Micafungin was recently licensed for neonates, children and adults for prophylaxis and treatment of invasive candidiasis in patients with prolonged neutropenia and after hemato‐ poietic stem cell transplantation [41]. The spectrum of activity is similar to that of Caspofungin (Table 1). The recommended dosage is 100 mg/day for invasive candidiasis (≤40 kg body weight: 2 mg/kg) with the option of dose escalation to 200 mg/day or 4 mg/kg/day; and 50 mg/ day (≤40 kg: 1 mg/kg) in the preventive indication [34]. The most frequent adverse events include vomiting, high fever, diarrhea, nausea, and hypokalemia [41].

#### **7. Conclusion**

Although various guidelines on antifungal management have been published, we suggest using a simple approach, which is guided by local factors, such as the pattern of resistance and the availability of diagnostic tools. As newer strategies might soon be implemented, we are unable to assess the efficacy of our approach to date. Our report underlines that many questions regarding antifungal treatment have to be addressed in future studies, such as the duration of treatment or the benefit of costly combination antifungal therapy.

#### **Acknowledgements**

the interaction of Voriconazole with a number of drugs (e.g. Vincristine, Cyclosporine A, and

This compound has a potent and broad-spectrum activity against most clinically important fungal infections, including zygomycetes, distinguishing it from the other azoles [33]. Accord‐ ing to the ECIL/ IDSA guidelines it is recommended as second-line treatment of aspergillosis, fusariosis, chromoblastomycosis and coccidioidomycosis. In addition, Posaconazole is approved for prophylaxis in high-risk patients older than 13 years of age with ALL and in hematopoietic stem cell transplant patients with graft-versus-host disease [31;39]. The dosage for prophylaxis is 200 mg three times daily, for salvage treatment the dose is increased to 400 mg two times daily. Similar to Voriconazole, interference with cytochrome P450 dependent

Caspofungin is active against Candida spp. and Aspergillus spp., but resistant against Cryptococcus species and zygomycetes (Table 1.). It is licensed for adult and pediatric patients, including neonates, for empirical antifungal therapy in persistently febrile neutropenic patients, for second-line pre-emptive therapy of suspected aspergillosis and for primary therapy in non-neutropenic patients with invasive Candida infections. The recommended dose regimen in adults consists of a single 70-mg loading dose on day 1, followed by 50 mg daily thereafter [34]. A dosage of 1 mg/kg for children has been suggested [31]. A favorable safety profile has been described, the most common drug-related adverse events were fever, increased ALT, and rash; few events were serious or required treatment discontinuation [40].

Micafungin was recently licensed for neonates, children and adults for prophylaxis and treatment of invasive candidiasis in patients with prolonged neutropenia and after hemato‐ poietic stem cell transplantation [41]. The spectrum of activity is similar to that of Caspofungin (Table 1). The recommended dosage is 100 mg/day for invasive candidiasis (≤40 kg body weight: 2 mg/kg) with the option of dose escalation to 200 mg/day or 4 mg/kg/day; and 50 mg/ day (≤40 kg: 1 mg/kg) in the preventive indication [34]. The most frequent adverse events

Although various guidelines on antifungal management have been published, we suggest using a simple approach, which is guided by local factors, such as the pattern of resistance and the availability of diagnostic tools. As newer strategies might soon be implemented, we are unable to assess the efficacy of our approach to date. Our report underlines that many

include vomiting, high fever, diarrhea, nausea, and hypokalemia [41].

Omeprazole) has to be considered [33].

metabolites (e.g. Cyclosporine) need to be considered [34].

328 Clinical Epidemiology of Acute Lymphoblastic Leukemia - From the Molecules to the Clinic

**6.5. Posaconazole**

**6.6. Caspofungin**

**6.7. Micafungin**

**7. Conclusion**

We thank Kinderkrebshilfe Tirol und Vorarlberg for funding.

### **Author details**

Roman Crazzolara\* , Adrian Kneer, Bernhard Meister and Gabriele Kropshofer

\*Address all correspondence to: roman.crazzolara@i-med.ac.at

Department of Pediatrics, Medical University of Innsbruck, Austria

### **References**


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## *Edited by Juan Manuel Mejia-Arangure*

This book describes different perspectives of childhood acute lymphoblastic leukemia. The approach includes aspects of molecular epidemiology, particularly molecular features that influence the genesis and prognosis of the disease. Some aspects of the prognosis of lymphoblastic leukemias are very detailed, highlighting the use of molecular biology in the early identification of complications that may occur in diseased patients. The authors of the present book conform a Mexican group who identifies the causes of leukemia, and they summarize their experience in research, results and proposals for future studies. A causal model is included in which the authors hypothesized the origin of acute lymphoblastic leukemias, particularly in children. This hypothesis can be useful to better understand other cancers during childhood. This book will help the reader to identify different molecular aspects involved in leukemia, and its relation to the development and evolution of the disease.

Clinical Epidemiology of Acute Lymphoblastic Leukemia - From the Molecules to the Clinic

Clinical Epidemiology

of Acute Lymphoblastic

Leukemia

From the Molecules to the Clinic

*Edited by Juan Manuel Mejia-Arangure*