FDA approves obecabtagene autoleucel for adults with relapsed or refractory B-cell precursor acute lymphoblastic leukemia

Regulatory approval: On Nov 8, 2024, the FDA approved obecabtagene autoleucel (Aucatzyl; Autolus), a CD19-directed genetically modified autologous T-cell immunotherapy, for adults with relapsed or refractory CD19-positive B-cell precursor acute lymphoblastic leukemia. Approval was supported by the single-arm FELIX trial (NCT04404660). In 65 evaluable patients, 42% achieved complete remission within 3 months; median duration of that CR was 14.1 months. Boxed warnings include CRS, ICANS, and T-cell malignancies.

FDA approval (Nov 8, 2024)

The US FDA approved obecabtagene autoleucel (Aucatzyl; Autolus Inc.), a CD19-directed genetically modified autologous T-cell immunotherapy, for adults with relapsed or refractory CD19-positive B-cell precursor acute lymphoblastic leukemia (ALL).

Key supporting evidence: FELIX (NCT04404660)

Approval was based on FELIX, an open-label, multicenter, single-arm trial in adults with relapsed/refractory CD19-positive B-cell ALL. Eligibility included relapse after a remission of ≤12 months, relapsed/refractory disease after ≥2 prior systemic therapy lines, or relapsed/refractory disease ≥3 months after allogeneic stem cell transplantation.

Primary efficacy measures: rate and duration of complete remission (CR) within 3 months post-infusion.

  • CR within 3 months: 27/65 patients (42%; 95% CI, 29%–54%)
  • Median duration of CR (within 3 months): 14.1 months (95% CI, 6.1 to not reached) Additional outcomes included overall complete remission (CR + CRi) at any time.

Safety and dosing highlights (label)

The prescribing information includes boxed warnings for cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS), and T-cell malignancies. Reported rates included CRS 75% (Grade 3, 3%) and neurologic toxicities 64% (Grade ≥3, 12%), with ICANS 24% (Grade ≥3, 7%).

Recommended total dose: 410 × 10^6 CAR-positive viable T cells, administered as a split infusion on Day 1 and Day 10 (±2 days) following fludarabine/cyclophosphamide lymphodepletion.

Full prescribing information is expected to be posted on Drugs@FDA.

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