Dr Roddie on Obe-cel in R/R B-ALL

Claire Roddie, MD, consultant hematologist, University College London Hospital, discusses the patient population and topline efficacy findings from the phase 1/2 FELIX trial (NCT04404660), which is investigating the CD19-directed CAR T-cell therapy obecabtagene autoleucel in patients with relapsed/refractory adult B-cell acute lymphoblastic leukemia.

Patients with relapsed B-ALL are difficult to treat, and the FELIX trial population included patients with high disease burden, Roddie says. Patients in this trial had a median age of 50 years, and 26.6% had Philadelphia chromosome (Ph)–positive disease. Moreover, patients had a median of 2 prior lines of therapy, and 30.9% of patients had received at least 3 prior lines. A total of 53.2% of patients were refractory to their last line of prior therapy. At screening, the median percentage of bone marrow blasts in the patients who received obe-cel was 49.5%. In addition, at pre-conditioning, 19.1% of patients had extramedullary disease, which confers a poor prognosis in patients with ALL, Roddie notes.

A total of 94% of patients who underwent leukapheresis received obe-cel in the trial, which is an encouraging number given the challenging patient population, Roddie explains. The median time from vein to release of obe-cel was 21 days. This quick turnaround time is important in this population, as patients with rapidly progressing disease cannot tolerate long periods without therapy, Roddie emphasizes.

In FELIX, the overall response rate (ORR) was 76%, and the complete response rate was 54.3%. Furthermore, 97% of evaluable responders achieved minimal residual disease negativity. At a median follow-up of 9.5 months, 61% of responders were in ongoing remission and had not received new anticancer therapies.

A subgroup analysis demonstrated ORRs of 95% in patients at least 65 years of age and 88% in patients with Ph-positive disease. Additionally, patients who had received 4 or more prior lines of therapy achieved an ORR of 58%, patients who had extramedullary disease at pre-conditioning had an ORR of 56%, and patients with over 75% to 100% bone marrow blasts achieved an ORR of 58%.

Disclosures: Dr Roddie reports honoraria from Autolus Therapeutics; consulting or advisory roles with Autolus Therapeutics; research funding from Autolus Therapeutics (Inst); and travel, accommodations, and expenses from Autolus Therapeutics.