Dr Park on the FDA Approval of Obe-Cel in Adult R/R ALL

“We are very excited to have another product approved for adult patients with ALL. [CAR T-cell therapy has come a long way in ALL] and is likely the first treatment where its true benefit and potential were demonstrated, initially gaining approval in the pediatric setting.”

Jae Park, MD, medical oncologist, chief, Cellular Therapy Service, Memorial Sloan Kettering Cancer Center, discusses the FDA approval of obecabtagene autoleucel (obe-cel; Aucatzyl) for the treatment of adult patients with relapsed or refractory B-cell precursor acute lymphoblastic leukemia (ALL) and its implications on clinical practice.

The regulatory decision was based on findings from the phase 1/2 FELIX trial (NCT04404660), Evaluable patients on enrolled on the study (n = 65) achieved a complete remission (CR) rate within 3 months of treatment of 42% (95% CI, 29%-54%). The median duration of CR for those who responded within 3 months was 14.1 months (95% CI, 6.1–not reached).

Park explains that although CAR T-cell therapy has revolutionized the treatment of ALL, particularly in younger patients, its application in adult patients has been limited due to the high incidence of severe cytokine release syndrome (CRS) and immune effector cell–associated neurotoxicity syndrome (ICANS). Although all patients who receive any CAR T-cell therapies may be prone to CRS or ICANS, patients with ALL have been associated with higher rates and more severe instances of these AEs when given CAR T-cell therapy, Park explains. These toxicities often necessitate intensive care unit admission and prolonged hospitalization, and the potential for these adverse effects has prevented some patients from accessing this method of therapy.

Obe-cel has distinguished itself after exhibiting significantly reduced instances of severe CRS and ICANS in adult patients with ALL treated in the FELIX study, he continues. Safety findings demonstrated that the rate of any-grade CRS was 75%, and the rate of grade 3 CRS was 3%. Any-grade neurologic toxicities occurred in 64% of patients, including ICANS at a rate of 24%. Grade 3 neurologic toxicities and ICANS occurred in 12% and 7% of patients, respectively.