Gamida Cell Reports StemEx® Phase II/III Study Safety and Efficacy Data

Jerusalem, Israel, — Gamida Cell announced today additional analyses for the Phase II/III, multi-center, multi-national, historical cohort-controlled study to evaluate efficacy and safety of StemEx® as an alternative transplantation treatment for patients with high risk leukemia and lymphoma. Twenty-five bone marrow transplant centers worldwide treating 101 patients with hematologic malignancies following myeloablative therapy who could not find a family related matched bone marrow donor participated in the study.

For the final analyses, the clinical study evaluated the effects of StemEx®, used as part of a transplantation regimen, in comparison with a contemporaneous control group that received double cord blood transplant (DCBT) 2006-2010. This is an updated and more relevant historical control group than the original control (1995-2005). The primary endpoint was defined as the proportion of overall mortality at 100 days after transplantation. 

Key findings show that a transplant using StemEx®: 

• Improves survival at 100 days post transplantation. The analysis of this primary endpoint shows 15.8% 100-day mortality in the StemEx® group and 24.5% in the control group (p= 0.035). The primary endpoint was first reported on February 4, 2013. Please click here to see press release.
• Increases the number of patients with early hematopoietic recovery: neutrophil engraftment failure rates were lower in the StemEx® group (cumulative incidence 8.1%) than in the control group (cumulative incidence 14.5%; p=0.086).
• Shortens time to neutrophil engraftment. In the regression model for cumulative incidence the median time to neutrophil engraftment was 21 days in the StemEx®  group and 28 days in the control group (p<0.0001).
• Shortens the time to platelet engraftment. In the regression model for cumulative incidence the median time to platelet engraftment was 54 days in the StemEx® group and 105 days in the control group (p=0.008).
• Provides a graft which is enriched with CD34+ stem/progenitor cells. CD34+ cells from the StemEx® portion correlate with early hematopoietic recovery of neutrophils (p=0.001) and platelets (p=0.007).
• The survival advantage was not statistically significant by day 180 with mortality of 32.7% in the StemEx® group and 34.7% in the control group (p=0.39). 
• Does not create a significant difference in the level of grade III-IV acute GvHD – 19.4% in the StemEx®  group and 16.9% in the control group (p=0.11).
• Is feasible with a robust manufacturing process and shipment logistics showing delivery within stability limits of 100% of all manufactured units, allowing prompt and reliable transplantation in multiple sites across three continents.

Adverse events and serious adverse events in the StemEx® treatment group appear to reflect events expected in a patient population with hematologic malignancies, who are at high risk for concomitant morbidity events and mortality, without increased risk of post-transplant complications.
Professor Guillermo Sanz, head of clinical hematology at the Department of Hematology of Hospital Universitario La Fe, Valencia, a lead principal investigator (PI) of the StemEx® trial and the PI who recruited the most patients for the study said, “We are very enthusiastic as we have personally witnessed very good results in the StemEx® Phase II/III study.  Unequivocally, StemEx® has shown to be a reliable expansion procedure. StemEx® produces a higher amount of stem/progenitor cells, has a shorter time to engraftment and has demonstrated a reduced non-relapsed mortality in comparison with un-manipulated cells derived from cord blood.”

“Phase II/III data suggests that StemEx® can serve as an alternative transplant treatment for patients who cannot find a matched bone marrow donor.  The company plans to meet with the FDA this spring and with the EMA this autumn to continue discussions on the regulatory pathway for marketing approvals,” said Dr. Yael Margolin, president and CEO of Gamida Cell.

To date, StemEx® has been developed by the Gamida Cell-Teva Joint Venture, equally owned by Gamida Cell and Teva Pharmaceutical Industries. The Joint Venture owns all global rights for the commercialization of StemEx®.  The Gamida Cell – Teva Joint Venture is currently seeking a strategic partner for the global commercialization of StemEx®.

Dr. David Snyder, vice president of clinical development and regulatory affairs said, “This is a proud day. We look forward to continuing the development of this important product and to being the first to bring an expanded allogeneic stem cell product to market.”

About StemEx®
StemEx® is a graft of an expanded population of stem/progenitor cells, derived from part of a single unit of umbilical cord blood and transplanted by IV infusion along with the remaining, non-manipulated cells from the same unit.  Cord blood has less matching requirements than bone marrow or peripheral blood transplants, providing the potential to increase the number of treated patients and to shorten the time it can take to find a match. However, there are a limited number of stem/progenitor cells in cord blood, enabling a quantity sufficient generally only for pediatric treatment. StemEx® employs a technology that expands this small number of cord blood stem/progenitor cells, increasing their therapeutic capacity for transplantation in adolescents and adults.