Autolus Therapeutics to present three clinical data updates on obe-cel

Autolus Therapeutics announces three abstracts to be presented at the European Hematology Association Congress, June 13-16, 2024. Oral presentation: Title: obecabtagene autoleucel in adult relapsed/refractory B cell acute lymphoblastic leukemia: Survival and potential impact of CAR T-cell persistence and stem cell transplantation in the FELIX study: Summary of Findings: This is an encore presentation of the findings presented at ASCO 2024. The overall response rate in all patients who received obe-cel in the FELIX study was 78%. At the February 7, 2024, data cut-off date, the majority of ongoing responders showed durable responses. Among the responding patients, at a median follow up of 21.5 months, 40% were in ongoing remission without subsequent stem cell therapy or other non-protocol specified therapy, while 18% proceeded to subsequent SCT while in remission, 5% started new anti-cancer therapy while in remission and 36% relapsed or died. The median event-free survival was 11.9 months and median overall survival was 23.8 months and the estimated 12-month EFS and OS rates were 49.5% and 61.1% respectively. These data support the potential of a long-term plateau of survival outcomes in patients receiving obe-cel. Ongoing CAR T persistence and B-cell aplasia were associated with improved EFS. This pattern is consistent with the Phase 1 ALLCAR19 data. Furthermore, SCT consolidation in remission following obe-cel did not appear to improve EFS or OS. Title: obecabtagene autoleucel for relapsed/refractory adult B-cell acute lymphoblastic leukemia: The impact of inotuzumab-containing bridging therapy on treatment outcomes: Summary of Findings: INO-containing bridging therapies were effective in reducing BM disease prior to lymphodepletion and administration of obe-cel. Our data suggests that reducing BM blasts as much as possible prior to lymphodepletion predicts EFS and OS outcomes; however, patients with high disease burden at screening are still at higher risk of relapse overall. Bridging therapy with INO was utilized in patients with higher disease burden and helped minimize the risk of CRS and ICANS without increasing liver toxicity. Choice of bridging therapy prior to obe-cel treatment, though influenced by clinical care variables, may impact outcomes for patients with R/R B-ALL. Further studies comparing bridging with INO-containing therapies or chemotherapy are warranted. Title: Droplet digital PCR and flow cytometry sensitivity for measuring CAR T-cell kinetics in adult patients with relapsed/refractory B-cell acute lymphoblastic leukemia treated with obecabtagene autoleucel: Summary of Findings: A strong correlation was observed between flow cytometry and ddPCR assays for assessment of CAR T levels in peripheral blood. ddPCR is a more sensitive technology than flow cytometry for monitoring CAR T persistence. Flow cytometry assays developed specifically for CAR T monitoring may be sufficiently sensitive to be of clinical relevance. Our data suggest that loss of CAR T persistence is associated with shorter EFS and may be taken into consideration, together with other parameters such as measurable residual disease, to help inform clinical monitoring post-obe-cel infusion. A validation cohort using an appropriately developed CAR T marking flow cytometry assay versus a ddPCR assay would be required to conclude on the most appropriate methods to inform clinical outcomes.