Researchers have reported promising results in a Phase I/II trial involving 37 patients with relapsed or refractory B-cell malignancies who were treated with a cord blood-derived natural killer (NK) chimeric antigen receptor (CAR), a cell therapy targeting CD19. Results showed an overall response (OR) rate of 48.6% 100 days after treatment, with one-year progression-free survival (PFS) and overall survival (OS) rates of 32% and 68%, respectively. The trial reported an excellent safety profile, with no cases of cytokine release syndrome (CRS), neurotoxicity or graft-versus-host disease. Another key finding of the trial was the importance of allogeneic cord blood donor selection criteria in the manufacture of CAR NK cells. Cord blood units cryopreserved within 24 hours of collection and those with a low content of nucleated red blood cells were associated with significantly better results. CAR NK cells generated from these units resulted in a one-year PFS rate of 69% and an OS rate of 94%, compared with 5% and 48%, respectively, for units with higher nucleated red cell content or longer collection to cryopreservation times.
