**4. UCB in clinical trials**

The first successful UCB transplantation was performed in 1988 in which the cells were able to reconstitute the immune system of a patient with Fanconi's anemia [132]. Since then, over 20,000 UCB transplants have been performed with more than 3000 UCB transplants now conducted each year [133]. UCB is routinely used in the clinic for acute leukemia, aplastic anemia, lymphomas, hemoglobinopathy and sickle cell disease [134–136]. Initially, there was concern that UCB therapies may struggle to translate to adult conditions as the number of cells present in UCB units is generally limited and less than required to treat adult conditions or when multiple doses are required. However, it is now been shown that it is feasible to use two independent UCB units at once to overcome insufficient cells present in a single UCB unit [137]. Furthermore, with rapid advances in technology for the expansion of stem cells, it is likely that expanded stem cells isolated from UCB units will allow administration of larger cell doses from a single UCB unit [133].

A potential mechanism by which UCB cells respond to and protect against brain injury is via stromal derived factor (SDF)-1. SDF-1 is upregulated in the neonatal brain 7-day post-HI injure and is derived from astrocytic end-feet processes along blood vessels and from endothelial cells [125]. UCB mononuclear cells express the SDF-1 receptor, CXCR4 and inhibition of SDF-1 reduces migration of UCB cells to the lesion site following neonatal HI injury [126]. In addition, monocyte chemoattractant protein (MCP)-1 and macrophage inflammatory protein (MIP)-1 receptors are expressed on UCB cells and could be other potential receptors that

Cytokines and chemokines play a central role in inflammation, and UCB cells have been shown to secrete MCP-1, interleukin (IL)-6, IL-8, IL-10, angiogenin, vascular endothelial growth factor, brain derived neurotrophic factor and platelet derived growth factor, which all have protective potential to mediate inflammation, apoptosis, cell survival and angiogenesis [128, 129]. Furthermore, coculture of UCB cells with neural cultures exposed to oxygen and glucose deprivation for over 3 days showed that UCB upregulated the expression of chemokines CCL5, CCL3 and CXCL10 and subsequently reduced neuronal apoptosis to levels

Sonic hedgehog (Shh) has also been postulated to play an important role in the neuroprotective potential of UCB cells. It was shown that, following UCB administration, there was reduced neonatal brain injury in the cortex and this was accompanied by an increased expression of both Shh and Gli-1 [86]. Furthermore, when cyclopamine, an inhibitor of Shh, was

Another aspect that is frequently discussed in relation to cell therapies for brain injury is the necessity of cells to enter the brain to elicit an effect, and whether the blood brain barrier (BBB) needs to be disrupted for this to happen. A study in neonatal rats that received a HI injury used mannitol, a drug that can increase BBB permeability, followed by administration of UCB cells [131]. They found that expression of neurotrophic factors was increased in the animals that received both UCB cells and mannitol, compared to either therapy alone, and neurobehavioral outcomes were improved at 7- and 14-day post-HI. Interestingly, mannitol did not increase the rate of UBC engraftment within the brain, but clearly disrupting the BBB increased the effectiveness of UCB therapy. This could be important as it suggests that man-

The first successful UCB transplantation was performed in 1988 in which the cells were able to reconstitute the immune system of a patient with Fanconi's anemia [132]. Since then, over 20,000 UCB transplants have been performed with more than 3000 UCB transplants now conducted each year [133]. UCB is routinely used in the clinic for acute leukemia, aplastic anemia, lymphomas, hemoglobinopathy and sickle cell disease [134–136]. Initially, there was concern that UCB therapies may struggle to translate to adult conditions as the number of

administered prior to the UCB treatment, neuroprotection was abolished [86].

nitol could extend the therapeutic window for UCB treatment after birth.

allow migration of UCB cells to the injured brain [127].

114 Umbilical Cord Blood Banking for Clinical Application and Regenerative Medicine

observed in normoxic cultures [130].

**4. UCB in clinical trials**

Cerebral palsy (CP) is the most well-recognized condition resulting from perinatal brain injury. It is a clinically described complex of motor symptoms, with disability ranging from mild motor coordination dysfunction through to significant hemiplegia or quadriplegia, reflecting variable injury to the young brain. The motor disabilities that define CP are also often coexistent with other serious deficits—1 in 2 children with CP have intellectual disabilities including cognition, memory, learning and behavior deficits; 1 in 4 have epilepsy; 1 in 4 cannot talk; 1 in 4 are incontinent [138]. Parents of infants with CP are actively seeking new treatment options, including the use of stem cell therapies, particularly UCB therapy [139]. Cerebral palsy is currently ranked as the second most commonly treated condition with stem cells, and Australia is the third highest ranked country of patient origin for overseas treatments [140].

There are now a number of registered clinical trials, and a few completed trials, investigating UCB cell treatment for CP in children ranging from 10 months to 20 years old (**Table 1**). Two randomized control trials (RCT) have published results; Min and colleagues [139] investigated allogeneic UCB in combination with erythropoietin (EPO) vs. EPO and rehabilitation or rehabilitation alone. Their cohort was treated between 10 months and 10 years of age after diagnosis of CP, and children received an average 30 million cells per kg. At 6 months after treatment, improvements in gross motor function measure and cognitive scores were observed using the Bayley Scale. Unfortunately, however, this trial did not assess the efficacy of UCB alone. The second RCT treated CP patients between 6- and 20-year old with allogeneic UCB and they received up to 20 million cells per kg [141]. At 1- and 3-month posttreatment, muscle strength improved and by 6 months improvements were observed on gross motor function measure. Interestingly, they noted that the higher the cell dose given to the patient the better the outcome, suggesting that cell dose is critical for efficacy. This is confirmed by a further study in which administration of greater number of allogeneic UCB cells was associated with better outcome at 36 months [142]. A handful of smaller, non-RCT trials have also added to our knowledge on the efficacy of UCB for treating established CP [142–144]. CP patients with diplegic or hemiplegic deficits improved more after receiving autologous UCB cells, than children with quadriplegic disorders [143]. A Duke University trial has been conducted for administration of fresh autologous UCB to infants diagnosed with hypoxic ischemic encephalopathy and undergoing hypothermia treatment [144]. While this study has not yet reported neuroprotective efficacy, it is the first to show safety and feasibility for the early use of UCB cells as a prevention/early intervention therapy, rather than a reparative therapy for established CP. The same group at Duke University have a number of clinical trials registered (**Table 1**) investigating both autologous and sibling matched UCB transplantation, while reports are encouraging, we still await results from these trials.



**Study title Main objective Institution Treatment Current status Trial** 

Sung Kwang Medical Foundation, Korea

Bundang CHA Hospital, Republic of Korea

Bundang CHA Hospital, Republic of Korea

Bundang CHA Hospital, Republic of Korea

University of Texas Health Science Centre, Houston, USA

Georgia Regents University, United States

Duke University Medical Centre, United States

Duke University Medical Centre, United States

Umbilical cord blood and erythropoietin combination

Donated umbilical cord blood units

Autologous umbilical cord blood

Donated umbilical cord blood units

Sibling umbilical cord blood

Allogeneic umbilical cord blood

Autologous umbilical cord blood or bone marrow

Infusion of red-cell depleted, mononuclear cell enriched cord blood

\*Completed Has results *Min* et al. *Stem Cells: Translational and Clinical Research, 2013 3:581*

To determine efficacy of umbilical cord blood and erythropoietin combination therapy for children with

116 Umbilical Cord Blood Banking for Clinical Application and Regenerative Medicine

To evaluate the efficacy of umbilical cord blood therapy for children with

To determine the efficacy of a single intravenous infusion of autologous umbilical cord blood for the treatment of pediatric patients with spastic cerebral palsy

To evaluate the efficacy of umbilical cord blood therapy for children with

A single site, phase I, prospective study of the safety of intravenous sibling cord blood infusion

To analyze cytokines related to clinical outcomes of allogeneic umbilical cord blood therapy for children with cerebral palsy

To compare the safety and effectiveness of two types of stem cells, (either banked cord blood or bone marrow), in children between the ages of 2–10

years with CP

To test the safety and effectiveness of a cord blood infusion in children who have motor disability due to cerebral palsy. The subjects will be children whose parents have saved their infant's cord blood, who have non-progressive motor disability, and whose parents intend to have a cord blood infusion

cerebral palsy

cerebral palsy

cerebral palsy

Allogenic umbilical cord blood and erythropoietin combination therapy for cerebral

palsy

Umbilical cord blood therapy for cerebral palsy

A randomized study of autologous umbilical cord blood reinfusion in children with cerebral palsy

Umbilical cord blood therapy for children with cerebral palsy

Assessment of the safety of allogeneic umbilical cord blood infusions in children with cerebral palsy

Allogeneic umbilical cord blood therapy in children with CP

Safety and effectiveness of banked cord blood or bone morrow stem cells in children with cerebral palsy (CP). (ACT for CP)

Safety and effectiveness of cord blood stem cell infusion for the treatment of cerebral palsy in children

**identifier**

Completed NCT01528436

Completed NCT01147653

Completed NCT01639404

Unknown NCT02025972

NCT02599207

NCT01988584

NCT01072370

Active, not recruiting

Currently recruiting

Currently recruiting

NCT01193660


**Table 1.** Current clinical trials being conducted, or recently completed, using umbilical cord blood in regenerative medicine therapies for the management of cerebral palsy and ischemic brain injury in the newborn.

A meta-analysis on the efficacy of all reported stem cell trials for children with CP was recently performed, demonstrating a statistically significant intervention effect when patients were followed short-term to 6 months following treatment [145]. Furthermore, the effect was greatest in the trials using UCB, and overall, the treatment effect highly favors the use of UCB with or without rehabilitation to treat children with CP (**Figure 2**).

The first autologous transplant of UCB for pediatric ischemic stroke has recently been reported [146]. The work reports a child with right spastic hemiplegia who received 250 million UCB mononuclear cells at 5 years of age. At 3 months after treatment, there was an improvement in motor control, and further improvements were observed at 18 months, however, no change was

**Figure 2.** Forest plot showing the gross motor function changes from UCB transplantation for treatment of established cerebral palsy (adapted with permission from Novak et al. [145]).

observed on MRI. Another recent trial investigated the use of UCB for congenital hydrocephalus, where patients received multiple doses of autologous UCB with a median cell dose of 19 million cells/kg/infusion. No adverse events were reported while the UCB was also well-tolerated [147].
