Patients with relapsed or refractory B-cell acute lymphoblastic leukemia (B-ALL) are receiving tisagenlecleucel (tisa-cel) earlier in their treatment regimens, therefore prolonging relapse-free survival (RFS) and reducing the use of hematopoietic stem cell transplantation (HSCT), according to a recent study.
The study was led by Rayne H. Rouce MD, of Baylor College of Medicine, and presented at the Society of Hematologic Oncology 2024 Annual Meeting in Houston, Texas. Dr. Rouce and colleagues aimed to examine the impact of tisa-cel on the patient treatment journey following its 2017 approval by the US Food and Drug Administration.
The researchers collected data for the noninterventional, prospective, longitudinal study using the Center for International Blood & Marrow Transplant Research (CIBMTR) registry. They gathered data on 974 patients who received the chimeric antigen receptor T-cell therapy.
Disease burden before infusion decreased from 18% in 2018 to 4% in 2022. The percentage of patients receiving tisa-cel while in morphologic complete remission increased from 34% in 2018 to 51% in 2022. Fewer patients were in third or greater relapse (14% in 2018 vs 2% in 2022).
The percentage of patients undergoing HSCT prior to tisa-cel infusion also decreased from 37% in 2018 to 15% in 2022. However, the rate of post-infusion HSCT remained unchanged at 34.5%. Reasons for post-infusion HSCT included relapse, persistent or progressive disease, or measurable residual disease positivity.
HSCT frequency decreased in patients with high-risk cytogenetics. Despite 72% of patients harboring a KMT2A rearrangement, only 16% received a prior HSCT and 43% received a post-infusion HSCT in 2017.
Censoring for HSCT increased the median RFS from 18 months in 2018 to 27 months in 2020. Without censoring, overall survival probabilities were 66 (95% CI, 61–71) and 62 (95% CI, 57–66), respectively.
“The use of HSCT in this setting should be carefully evaluated,” the researchers noted.
Reference
Rouce RH, Baumeister SHC, Curran KJ, et al. Evolution of tisagenlecleucel use for the treatment of pediatric and young adult relapsed/refractory (R/R) B-cell acute lymphoblastic leukemia (B-ALL): Center for International Blood & Marrow Transplant Research (CIBMTR) registry results. Abstract #ALL-173. Presented at the Society of Hematologic Oncology 2024 Annual Meeting; September 4-7, 2024; Houston, Texas.