WEDNESDAY, Dec. 11, 2024 (HealthDay News) -- For patients with relapsed or refractory B-cell acute lymphoblastic leukemia (ALL), obecabtagene autoleucel (obe-cel), an autologous 41BB-ζ anti-CD19 chimeric antigen receptor (CAR) T-cell therapy, results in a high incidence of durable response, according to a study published online Nov. 27 in the New England Journal of Medicine.
Claire Roddie, M.D., from University College London, and colleagues conducted a phase 1b-2 multicenter study of obe-cel in 153 adults with relapsed or refractory B-cell ALL. Patients in cohort 2A (94 patients) had morphologic disease, while those in cohort 2B had measurable residual disease.
Overall, 127 patients received at least one infusion of obe-cel and were evaluable. The researchers found that overall remission occurred in 77 percent of patients in cohort 2A, with complete remission in 55 percent and complete remission with incomplete hematologic recovery in 21 percent. The prespecified null hypotheses (overall remission [≤40 percent] and complete remission [≤20 percent]) were rejected. The median event-free survival was 11.9 months in the 127 patients who received at least one obe-cel infusion, while the estimated six- and 12-month event-free survival was 65.4 and 49.5 percent, respectively. The median overall survival was 15.6 months, with 80.3 and 61.1 percent estimated six- and 12-month overall survival, respectively. In 2.4 percent of the patients, grade 3 or higher cytokine release syndrome developed, while grade 3 or higher immune effector cell-associated neurotoxicity syndrome developed in 7.1 percent.
"Obe-cel was associated with durable responses, particularly in patients with a low-to-intermediate bone marrow burden, including patients who did not receive consolidative allogeneic stem-cell transplantation," the authors write.
The study was funded by Autolus Therapeutics.
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