Omidubicel, a novel cellular therapy, expands the availability of allogeneic (donor) stem cell transplants to more patients
On April 17, 2023, the U.S. Food and Drug Administration (FDA) approved omidubicel — a new and potentially life-saving stem cell treatment option for adult and pediatric patients with high-risk blood cancers, including leukemia and lymphoma.
Omidubicel, which is being marketed by Israel-based Gamida Cell Ltd. under the brand name Omisirge®, is a donor umbilical cord blood–based cellular therapy — the first and only modified allogeneic (donor) umbilical cord blood–based stem cell transplant product to receive Breakthrough Therapy designation from the FDA.
Omidubicel’s approval was backed by promising results from a multi-center international phase 3 clinical trial led by Mitchell Horwitz, MD, director of the Adult Blood and Marrow Transplant Program at Duke Cancer Institute (DCI). Investigators found that the omidubicel product worked better and faster and was safer than a conventional umbilical cord blood stem cell transplant. The findings were published in October 2021 issue of the journal Blood, with Horwitz as lead author. A health-related, quality-of-life, 10-year follow-up study, led by DCI Hematology-Oncology Fellow Chenyu Lin, MD, was published in January 2023 in the journal Transplantation and Cellular Therapy.
Omidubicel expands access to needed treatment for adults and children over 12 who are unable to receive a bone-marrow-derived allogeneic stem cell transplant (the most common type of stem cell transplant) because they can’t find a genetically similar related or unrelated donor “match,” and who are too big to receive a conventional umbilical cord blood–based stem cell transplant, which doesn’t require a match.
“Stem cells are dosed based on body weight. The larger you are, the less likely you are to find a large enough unit of cord blood, which is why cord blood–based stem cell transplants have historically had more success in small children,” explained Horwitz. “A low dose of cord blood stem cells can work but may lengthen and/or compromise the chances of engraftment — when donor stem cells settle into the patient’s bone marrow or 'home in' and begin growing new red and white blood cells and platelets.”
Omidubicel takes care of the volume issue — the biggest drawback to a cord blood–based stem cell transplant — by expanding it. The cellular therapy (omidubicel) is manufactured by culturing (in a dish in the lab) and multiplying donor cord blood stem cells and progenitor cells for three weeks in the presence of nicotinamide, a derivative of vitamin B3 (niacin). Nicotinamide, said Horwitz, is believed to be the key component of the culture system that allows for safe and effective growth of the cord blood progenitor cells, whose capacity for self-renewal is more limited than that of stem cells. (Progenitor cells are descendants of stem cells. The two are similar in that they can self-renew and differentiate into/grow specific types of cells. Self-renewal in progenitor cells is limited, however, and unlike stem cells, which can differentiate into any cell type in the blood, progenitor cells may only be able to differentiate into one or two cell types.)