Autolus Therapeutics announces data from AUTO1/22 trial

Autolus Therapeutics announces a publication on the AUTO1/22 Phase 1 study in Pediatric B-cell Acute Lymphoblastic Leukemia in the journal Blood,1 previously presented this year at the European Society for Blood and Marrow Transplantation in April. CD19 negative relapse is a major cause of treatment failure after CD19 CAR T cell therapy for pediatric B-ALL. To address this, AUTO1/22 is designed to target both CD19 and CD22 using the fast-off rate CD19 CAR from obecabtagene autoleucel combined with a novel CD22 CAR capable of effective signaling in response to low antigen density/ Twelve patients with advanced pediatric B-ALL were treated. Patients on study were high risk, with 4 patients who had failed prior CD19 CAR therapy, 3 patients with a CD19-negative disease component, 3 patients with non-CNS extramedullary disease and 6 patients who had received prior blinatumomab. AUTO1/22 maintained the safety profile of obe-cel alone, with no cases of severe cytokine release syndrome. AUTO1/22 induced MRD-negative CR in 83% patients. This includes 2 patients who had CD19 negative disease, demonstrating the efficacy of the CD22 CAR. Two patients failed to respond: one with CD19+/CD22+ disease and another with progression of double CD19-/CD22- disease, present as a minor leukemic cell population pre-infusion. Of 10 responding patients, 5 had emergence of MRD or frank relapse with CD19 and CD22 expressing disease associated with loss of CAR T-cell persistence. Importantly, there were no cases of relapse due to antigen-negative escape, with a median follow-up of 8.7 months. Overall survival was 75% at 6 and 12 months. Six and 12-month event free survival were 75% and 60% respectively.