FDA Approves Brexucabtagene Autoleucel for Adults With Relapsed/Refractory ALL

The FDA has granted approval to brexucabtagene autoleucel (Tecartus) for the treatment of adult patients with relapsed or refractory B-cell precursor acute lymphoblastic leukemia (ALL), according to a press release issued by the FDA.

Brexucabtagene autoleucel is an autologous, anti-CD19 chimeric antigen receptor (CAR) T-cell therapy that includes T-cell enrichment. The FDA approval of this agent is supported by results from the phase 1/2 ZUMA-3 (NCT02614066).¹

In the study, ZUMA-3 125 patients were enrolled to assess the coprimary end points of the percentage of participants experiencing dose-limiting toxicities (DLTs) and overall complete remission (CR) rate. Secondary end points included duration of remission, minimum residual disease negative remission rate, allogeneic stem cell transplant rate, overall survival, and relapse-free survival.

Patients were treated with a conditioning chemotherapy regimen of fludarabine and brexucabtagene autoleucel. This is then followed by a single infusion of CAR transduced autologous T cells administered intravenously at a target dose of 2 x 10⁶ anti-CD19 CAR+ T cells/kg or 1 x 10⁶ anti-CD19 CAR+ T cells/kg.

Results published in Blood showed that the CAR T agent achieved a high response rate and tolerable safety in adults with R/R B-ALL. The overall complete remission rate observed was 83% among patients treated at the lowest dose level and 69% in all treated patients. At a median follow-up of 22.1 months (range, 7.1-36.1 months), the median duration of remission was 17.6 months (95% CI, 5.8-17.6) in patients treated with 1 × 106 cells per kg and 14.5 months (95% CI, 5.8-18.1) in the overall population.²

In terms of safety, the were no DLTs observed in the DLT-evaluable cohort.² According to the FDA prescribing information, CRS can occur in 92%, 26% being high-grade events. Neurologic adverse events can occur in 87% of patients treated with brexucabtagene autoleucel with 35% being high-grade events. The most common non-laboratory AEs observed with brexucabtagene autoleucel are those that occur in ≥ 20% of patients. These common AEs include fever, CRS, hypotension, encephalopathy, tachycardias, nausea, chills, headache, fatigue, febrile neutropenia, diarrhea, musculoskeletal pain, hypoxia, rash, edema, tremor, infection with pathogen unspecified, constipation, decreased appetite, and vomiting.¹

Based on toxicity and efficacy, the FDA-recommended dose of brexucabtagene autoleucel is 1 intravenous infusion of 1 x 10⁶ CAR-positive viable T cells per kg body weight with a maximum dose of 1 x 10⁸ CAR-positive viable T cells). The administration of brexucabtagene autoleucel should be followed by fludarabine and cyclophosphamide for lymphodepleting chemotherapy.

_REFERENCES:

_{1. FDA approves brexucabtagene autoleucel for relapsed or refractory B-cell precursor acute lymphoblastic leukemia. FDA. October 1, 2021. Accessed October 1, 2021.}

_{2. Shah BD, Bishop MR, Oluwole OO, et al. KTE-X19 anti-CD19 CAR T-cell therapy in adult relapsed/refractory acute lymphoblastic leukemia: ZUMA-3 phase 1 results. Blood. 2021;138 (1):11–22. doi: 10.1182/blood.20200090981.}