Dr Jabbour on the FDA Approval of Obe-Cel for Adult Patients With Relapsed or Refractory B-cell Precursor ALL

This approval comes at a critical time [and represents a] major milestone… benefiting both patients with ALL and the clinicians dedicated to treating this disease.

Elias Jabbour, MD, professor, Department of Leukemia, Division of Cancer Medicine, The University of Texas MD Anderson Cancer Center, discusses the FDA approval of obecabtagene autoleucel (obe-cel; Aucatzyl) for adult patients with relapsed or refractory B-cell precursor acute lymphoblastic leukemia (ALL).

On November 8, 2024, the FDA approved obe-cel for use in adult patients with relapsed or refractory B-cell precursor ALL, providing a new therapeutic option for a population with limited treatment success and poor outcomes upon relapse, Jabbour begins. The approval was based on data from the phase 1/2 FELIX trial (NCT04404660), which evaluated obe-cel in adult patients with relapsed or refractory B-cell precursor ALL.

Data demonstrated that among evaluable patients (n = 65), the overall complete remission (CR) rate within 3 months of treatment was 42% (95% CI, 29%-54%). The median duration of CR for those who responded within 3 months was 14.1 months (95% CI, 6.1-not reached). Jabbour notes that the observed plateau in survival curves indicates potential long-term disease control and possible curative outcomes for some patients.

Jabbour adds that obe-cel was associated with a favorable safety profile. Cytokine release syndrome (CRS) and immune effector cell–associated neurotoxicity syndrome (ICANS) occurred at low rates. Any-grade CRS occurred in 75% of patients, with 3% experiencing grade 3 or higher CRS. The median onset of CRS was approximately 9 days post-infusion, and the median duration of CRS was approximately 5 days.

ICANS of any grade was observed in 24% of patients, with 7% experiencing grade 3 or higher ICANS. The median onset of ICANS was approximately 15 days post-infusion, with a median duration of approximately 8 days.

Other commonly observed grade 3 or higher adverse effects (AE), regardless of causality, included febrile neutropenia in 25.5% of patients and anemia in 19.1% of patients. Overall, Jabbour notes that the AE profile is both manageable and reversible, which indicates that obe-cel could be administered safely, even in outpatient settings.

Jabbour emphasizes that obe-cel’s approval offers a promising new approach for managing relapsed/refractory B-cell precursor ALL. In this high-risk population, current treatment options often provide only short-term remission, necessitating stem cell transplantation with associated risks. The durability of response with obe-cel may reduce reliance on transplant, offering patients hope for longer-term remission without subsequent interventions, Jabbour concludes.