FDA OKs Cell Therapy to Lower Infection Risk After Stem Cell Transplant

The FDA approved omidubicel (Omisirge) to reduce the risk for infections in hematologic cancer patients undergoing stem cell transplant, the agency announced on Monday.

Omidubicel is designed to speed up neutrophil recovery and is indicated for patients ages 12 and up planning to undergo umbilical cord blood transplantation (UCBT) following a myeloablative conditioning regimen, which can impair the immune system.

"Today's approval is an important advance in cell therapy treatment in patients with blood cancers," Peter Marks, MD, PhD, director of FDA's Center for Biologics Evaluation and Research, said in a statement. "Hastening the return of the body's white blood cells can reduce the possibility of serious or overwhelming infection associated with stem cell transplantation."

Administered as a single intravenous dose, the cell therapy is "composed of human allogeneic stem cells from umbilical cord blood that are processed and cultured with nicotinamide (a form of vitamin B3)," according to the agency, with each patient-specific dose containing healthy cells from a pre-screened donor.

Support for the approval came from a randomized multicenter trial (Study P0501) that compared omidubicel to UCBT in 125 patients (ages 12 to 65) with hematologic malignancies who had undergone myeloablative conditioning, including with total body irradiation or chemotherapy. The study's primary endpoint was time to neutrophil recovery and a key secondary outcome was incidence of infection following transplant.

Of the patients randomized to omidubicel, 87% achieved neutrophil recovery (median 12 days posttransplant), as compared with 83% of those assigned to UCBT (median 22 days posttransplant).

At 100 days posttransplant, incidence of grade 2/3 bacterial or grade 3 fungal infections were seen in 39% and 60% of the two groups, respectively. Recently reported data from the trial also hinted at a potential survival benefit with the product.

The most common grade ≥3 adverse events in patients receiving omidubicel included pain in 33%, mucosal inflammation in 31%, hypertension in 25%, and gastrointestinal events in 19%. In addition, acute graft-versus-host disease occurred in 58%, infusion reactions in 47%, chronic graft-versus-host disease in 35%, and graft failure in 3%.

Similar to approved UCBT products, the FDA warned of the potential for severe side effects, and omidubicel carries a boxed warning for infusion reactions, graft-versus-host disease, engraftment syndrome, and graft failure. Other warnings include the potential for "transmission of serious infections or rare genetic diseases from the donor cells," with the agency noting that patients should be monitored for these following treatment, as well as for secondary cancers.

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