On November 8, 2024, the Food and Drug Administration approved obecabtagene autoleucel, a CD19-directed genetically modified autologous T cell immunotherapy, for adults with relapsed or refractory B-cell precursor acute lymphoblastic leukaemia (ALL).

Full prescribing information will be posted on Drugs@FDA. 

Efficacy and Safety

Efficacy was evaluated in FELIX (NCT04404660), an open-label, multicenter, single-arm trial that enrolled adults with relapsed or refractory CD19-positive B-cell ALL.

Enrolled patients were required to have relapsed following a remission lasting 12 months or less, relapsed or refractory ALL following two or more prior lines of systemic therapy, or disease that was relapsed or refractory 3 or more months after allogeneic stem cell transplantation. 

The major efficacy outcome measures were rate and duration of complete remission (CR) achieved within 3 months after infusion.

Additional outcome measures were rate and duration of overall complete remission which includes complete remission and complete remission with incomplete haematologic recovery (CRi), at any time.

Of the 65 patients evaluable for efficacy, 27 patients (42%; 95% confidence interval [CI]: 29%, 54%) achieved CR within 3 months.

The median duration of CR achieved within 3 months was 14.1 months (95% CI: 6.1, not reached). 

The prescribing information has a boxed warning for cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS) and T cell malignancies.

CRS occurred in 75% (Grade 3, 3%) and neurologic toxicities occurred in 64% (Grade ≥3, 12%), including ICANS in 24% (Grade ≥3, 7%).

The most common non-laboratory adverse reactions (incidence ≥ 20%) included CRS, infections-pathogen unspecified, musculoskeletal pain, viral infections, fever, nausea, bacterial infectious disorders, diarrhoea, febrile neutropenia, ICANS, hypotension, pain, fatigue, headache, encephalopathy, and haemorrhage.

The total recommended dose of obecabtagene autoleucel is 410 X 106 CD19 chimeric antigen receptor (CAR)-positive viable T cells to be administered as split dose infusion on Day 1 and Day 10 (±2 days) based on bone marrow blast assessment and preceded by fludarabine and cyclophosphamide lymphodepleting chemotherapy. 

Expedited Programs 

This review used the Assessment Aid, a voluntary submission from the applicant to facilitate the FDA’s assessment. 

This application was granted regenerative medicine advanced therapy designation and orphan drug designation.

FDA expedited programs are described in the Guidance for Industry: Expedited Programs for Serious Conditions-Drugs and Biologics.

A description of FDA expedited programs for RMAT is in the Guidance for Industry: Expedited Programs for Regenerative Medicine Therapies for Serious Conditions. 

Healthcare professionals should report all serious adverse events suspected to be associated with the use of any medicine and device to FDA’s MedWatch Reporting System or by calling 1-800-FDA-1088.

For assistance with single-patient INDs for investigational oncology products regulated by the Center for Biologics Evaluation and Research, healthcare professionals may email OTPRPMS@fda.hhs.gov. 

Follow the Oncology Center of Excellence on X: @FDAOncology

Source: FDA