UK MHRA grants conditional marketing authorization to obecabtagene autoleucel for the treatment of adult patients with R/R B-ALL

On April 28, 2025, the UK Medicines and Healthcare products Regulatory Agency (MHRA) granted conditional marketing authorization to obecabtagene autoleucel (obe-cel), an autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy, for the treatment of adult patients with relapsed/refractory (R/R) B-cell acute lymphoblastic leukemia (B-ALL).¹ This approval was based on promising results from the FELIX trial (NCT04404660).¹  

FELIX study¹ 

FELIX is an ongoing phase Ib/II, open-label, multicenter, single-arm study designed to evaluate the safety and efficacy of obe-cel in adult patients with B-ALL.² The ALL Hub previously reported on the efficacy and safety and tumor burden-guided dosing data for obe-cel from the FELIX study. The key results in evaluable patients with R/R B-ALL (n = 127) were as follows:¹ 

• The complete response/complete response with incomplete hematological recovery for patients who received at least one infusion of obe-cel was 76.6%.
• The median response duration for all infused patients was 21.2 months.  
• The median event-free survival (EFS) was 11.9 months, and the estimated 6- and 12-month EFS rates were 65.4% and 49.5%, respectively.
• The most common non-laboratory Grade ≥3 or higher adverse reactions were infections: pathogen unspecified (32%), febrile neutropenia (24%), and bacterial infectious disorders (11%). Cytokine release syndrome and immune effector cell-associated neurotoxicity syndrome were reported in 68.5% (Grade ≥3 in 2.4%) and 22.8% (Grade ≥3 in 7%) of patients, respectively. 

Obe-cel received marketing approval by the U.S. Food and Drug Administration (FDA) as a consolidation therapy for the treatment of adult patients with R/R B-ALL on November 8, 2024.