Obecabtagene Autoleucel Under Review for Relapsed/Refractory B-Cell ALL

The Food and Drug Administration (FDA) has accepted for review the Biologics License Application (BLA) for obecabtagene autoleucel (obe-cel) for the treatment of relapsed or refractory adult B-cell acute lymphoblastic leukemia (ALL).

Obe-cel is an investigational autologous chimeric antigen receptor (CAR) T-cell therapy designed with a fast off-rate CD19 binder to reduce toxicity and increase long-term persistence. The BLA is supported by data from the phase 2 FELIX trial (ClinicalTrials.gov Identifier: NCT04404660), which included 127 patients with relapsed or refractory B-cell ALL who received obe-cel treatment. 

Findings showed the overall remission rate (defined as the proportion of patients achieving a complete response [CR] or CR with incomplete hematologic recovery [CRi]) was 78% (median follow-up time was 16.6 months). Among patients with morphologic disease (defined as ≥5% bone marrow [BM] blasts or presence of extramedullary disease [EMD] regardless of BM blast status; n=98), 74% achieved CR or CRi; 95% of evaluated responders were minimal residual disease (MRD)-negative. Among patients with no morphologic disease (n=29), 100% were MRD-negative. 

Across all treated patients, the event free survival estimate (EFS) at 12 months was reported to be 50%; only 17% of responders proceeded to stem cell transplant while in remission. Patients with lower leukemic burden at lymphodepletion were found to have better outcomes.

The safety profile of obe-cel was considered favorable, with 2% of patients experiencing grade 3 or greater cytokine release syndrome and 7% experiencing grade 3 or greater immune effector cell-associated neurotoxicity syndrome. Higher leukemic burden at lymphodepletion was associated with a greater likelihood of severe toxicity.

“Acceptance of the BLA filing is an important milestone for Autolus and we look forward to continuing our collaboration with the FDA during the review cycle,” said Dr Christian Itin, Chief Executive Officer of Autolus. “With the PDUFA date set for November, we remain focused on preparing for the potential launch of obe-cel.”

A regulatory decision is expected on November 16, 2024. 

This article originally appeared on MPR