**Author details**

results for CB thawing [44, 47, 48, 60–68]. Chow et al. [18, 21, 50–59] was the first group to report superior clinical outcome with bedside direct infusion over post-thaw wash, with improved neutrophil and platelet engraftment, reduced transplant-related mortality, decreased extensive cGvHD, increased limited cGvHD, and enhanced overall and disease-free

20 Umbilical Cord Blood Banking for Clinical Application and Regenerative Medicine

To address the question of whether the presence of residual RBC in the cryopreserved MaxCell products may adversely affect the outcome of HSCT, we have previously reported on the outcomes of 118 MaxCell CB transplants for patients with both hematological malignancies and nonmalignant indications [8]. Our experience indicates a 90.3% cumulative incidence for neutrophil (ANC500) engraftment, 75.5% for platelet 20K engraftment, 16.3% for 100-day transplant-related mortality, 65.5% for 1-year overall survival, and 51.6% for 1-year diseasefree survival. This was followed by another series with 120 patients with nonmalignant indications [39] with similar outcome. At this point, after thousands of MaxCell CB products have been transplanted at around 300 transplant centers, that favorable experience reported previously has been maintained [[18, 35–43, 50–59], Chow et al. unpublished observations].

Because of the two- to threefold increased availability of high-cell dose CB products as a result of MaxCell CB processing, and the outstanding clinical outcome observed to date, it may be appropriate to ask whether it is reasonable to discard all the stem cell, progenitor cell, nucleated cell, and mononuclear cell in order to preserve storage space and reduce cost [13]. In fact, even the space cost savings argument is probably negated by the increased potential revenue generated from much higher availability of high-cell dose CB products. However, more importantly, is whether depriving patients of the opportunity to access the same HLA-matched CB products with higher cell doses can be justified in the name of economics. Cost, the original reason NYBC developed these RCR techniques, appears to be insufficient [13] if cell dose and in turn, clinical outcome and patient survival are compromised. As an example, a 25%

TNC/kg body

improvement in infused cell dose can take a product from a suboptimal 2.0 × 107

TNC/kg body weight.

To summarize, The results of outcome of the patients in the first MaxCell series [18] appear to be at least comparable to those reported in the medical literature [19, 23–34] and in some instances, superior to those reported for RCR CB products [18, 35–43, 50–59]. Though, there are no published data indicating inferior outcomes with transplantation using MaxCell units [8, 35–43, 50–59], such retrospective comparisons cannot be definitive. To analyze rigorously the outcomes of MaxCell CBT in comparison with RCR units, matched-pair comparisons for pediatric hematologic malignancies and thalassemia have shown significant improvements in overall survival, disease-free survival, transplanted-related mortality, and platelet engraftment for MaxCell CB products [35–38]. Moreover, when MaxCell CB products are coupled with direct infusion, significantly improved overall survival, disease-free survival, transplantedrelated mortality, neutrophil, and platelet engraftment, higher limited cGvHD but lower

survival.

**5. Conclusion**

weight to an adequate 2.5 × 107

Robert Y.K. Chow1,2\*, Qingyu Li1,2, Christine Chow1,2, Vincent Guo1,2, Tracie Dang1,2, Andrew Rao1,2, Tony Zeng1,2, Delon Te-Lun Chow1,2, Baixiang Wang1,2 and Michelle Chow1,2

\*Address all correspondence to: rchow@cytetherapeutics.com

1 CyteTherapeutics, Inc., Irvine, California, USA

2 CyteTherapeutics, Inc., Beijing, PR China
