SALT LAKE CITY – Recipients of hematopoietic cell transplant with umbilical cord blood CD34+ cells expanded with an aryl hydrocarbon receptor (AHR) antagonist had a significantly higher rate of engraftment and comparable survival to a historical cohort of umbilical cord blood recipients.
The robust expansion of donor umbilical cord blood seen with the new technique opens the door for better use of umbilical cord blood inventory with superior human leukocyte antigen (HLA) matching,, said at a top abstracts session of the combined annual meetings of the Center for International Blood & Marrow Transplant Research and the American Society for Blood and Marrow Transplantation.
The new technique still shared the benefits of low rates of graft-versus-host disease (GVHD) and high survival that have been seen in previous umbilical cord blood transplants, with no significant difference in overall survival, relapse, or acute or chronic GVHD.
Compared to historical controls (n = 151), patients receiving the AHR antagonist–expanded umbilical cord blood (UCB) cells with myeloablative conditioning (n = 9) saw complete and more rapid engraftment (100% vs. 89% engraftment at a median 14 days vs. 23 days; P less than .01), reported Dr. Wagner of the University of Minnesota, Minneapolis.
These and other results came from two arms of a phase 2 trial of MGTA-456 (the working name of the AHR-expanded UCB cells). Twenty patients were to receive MGTA-456 derived from partially matched umbilical cord blood units after either myeloablative or nonmyeloablative conditioning; one patient in each arm had low expansion of UCB, so a total of 18 patients received MGTA-456. Each intervention arm was compared with a historical control arm that had received conventional UCB units.
In the myeloablative arm, patient demographics and disease characteristics were similar to the control cohort except that the MGTA-456 patients were significantly heavier (93.8 kg vs. 66.7 kg; P less than .04).