CAR T-Cell Therapy, Stem Cell Transplant May Reduce Risk of Relapse in Children With B-ALL

April 13, 2021

Children and young adults with B-cell acute lymphoblastic leukemia (B-ALL) who receive an allogeneic hematopoietic stem-cell transplant (HSCT) following CD19 chimeric antigen receptor (CD19-CAR) T-cell therapy may be less likely to relapse, according to findings published recently in the Journal of Clinical Oncology. Previous studies have shown that CD19-CAR T cells induce high response rates in this population, but relapse rates are high. 

The trial followed 50 children and young adults with B-ALL who were treated with CD19-CAR T cell therapy, with a median follow-up of 4.8 years. Thirty-one (62%) patients achieved complete remission, and 28 (90.3%) of these patients were minimal residual disease (MRD)−negative by flow cytometry. Twenty-one (75%) of the 28 MRD-negative patients proceeded to allogeneic HSCT after CAR T-cell therapy. Of these patients, two (9.5%) had relapsed at 24 months of follow up, whereas all patients who did not receive a stem cell transplant had relapsed. For those proceeding to allogeneic HSCT, median overall survival was 70.2 months, compared to 10.5 months for all patients.

According to investigators, the findings provide strong evidence that a treatment regimen incorporating autologous CD19-CAR T cells to achieve remission followed by a consolidative allogeneic HSCT is associated with a remarkably low relapse rate in this high-risk patient population.

“More than 50% of kids in other studies with a different CAR [suffer] relapse, with the majority of them losing the target the CAR goes after,” said co-author Daniel Lee, MD, a pediatric oncologist and director of Pediatric Stem Cell Transplant and Immunotherapy at University of Virginia (UVA) Children’s and the UVA Cancer Center. “Most of these kids have a single shot at this life-saving and paradigm-changing therapy called CAR T-cells. We should do all we can to maximize the chance for a cure, and right now that means a transplant after CAR therapy for most.”

The authors concluded that prospective trials that directly incorporate consolidative allogeneic HSCT following CAR T cell therapy are necessary to further evaluate how to improve outcomes for these high-risk patients.