Data Published in Transplantation and Cellular Therapy Suggest Antiviral Protection After Transplantation with Gamida Cell’s Omisirge (omidubicel-onlv)

Gamida Cell Ltd. (Nasdaq: GMDA), a cell therapy pioneer working to turn cells into powerful therapeutics, today announced the publication in press of a prospective sub-study of the Phase 3 clinical trial for Omisirge (omidubicel-onlv), the company’s allogeneic stem cell transplant therapy, characterizing immune reconstitution kinetics following hematopoietic stem cell transplantation (HCT) with Omisirge compared to umbilical cord blood (UCB). The article appears online on the Transplantation and Cellular Therapy journal website.

Thirty-seven patients (Omisirge: n=17, UCB: n=20) from 14 global sites were included in the sub-study and blood samples were collected from seven to 365 days post-transplantation. Omisirge was found to facilitate faster immune reconstitution, including natural killer (NK) cell and helper T (Th) cell reconstitution than UCB before day 28 post-transplantation. The early reconstitution may account for the reduced rate of viral infections observed after transplantation with Omisirge versus UCB.

“The speed of immune reconstitution is critical for patients who are vulnerable to infection immediately following transplant,” said Mitchell Horwitz, M.D., senior author of the publication and stem cell transplant specialist and Professor of Medicine at Duke Cancer Institute. “These data suggest that Omisirge generates rapid functional recovery of the immune system, which may be associated with the lower rate of viral infections observed among patients who received Omisirge.”

• Omisirge recipients demonstrated an up to 70-fold advantage over patients who received UCB in median cell counts across most cell populations, occurring predominantly in the short-term post-transplantation setting, including NK and T cell reconstitution in the first two weeks post-transplantation. By three weeks post-HCT, Omisirge recipients were 3 times more likely to achieve clinically relevant Th and NK cell counts of 100 cells/µL or above.
• Omisirge recipients received a 33-fold higher median dose of CD34+ stem cells than UCB recipients. The CD34+ cell content for recipients transplanted with Omisirge correlated with faster immune reconstitution by Day 7 post-HCT, which in turn coincided with earlier hematopoietic recovery.
• Omisirge recipients exhibited superior reconstitution of B cells, dendritic cells and monocytes.
• Clinical outcomes in this sub-study were consistent with those from the Phase 3 study for Omisirge. The rate of grade 2/3 infections in the first year were significantly lower with Omisirge than with UCB: 29% vs 70% for bacterial infections and 6% vs 45% for viral infections. No differences were reported in incidence of acute or chronic GVHD between the Omisirge transplanted patients and the UCB transplanted patients.

“The approval of Omisirge was based on the reduced time to neutrophil recovery and reduced risk of infection compared to standard cord blood,” said Ronit Simantov, M.D., Chief Medical and Scientific Officer of Gamida Cell. "The robust recovery of multiple immune cell populations we observed provides a potential mechanism for the reduced incidence of serious bacterial, fungal and viral infections associated with Omisirge transplantation.”