Tisagenlecleucel CAR-T Therapy Achieves 81% Remission in Paediatric Relapsed ALL
This global phase 2 study of tisagenlecleucel in paediatric and young adult patients with relapsed or refractory B-cell ALL reported an 81% overall remission rate, with all responders achieving MRD negativity by flow cytometry. Overall survival was 76% at 12 months with durable CAR-T cell persistence up to 20 months. The study established flow cytometric MRD assessment as the standard response measure for CAR-T therapy in ALL and led to the first FDA-approved CAR-T product.
The original study
Tisagenlecleucel in Children and Young Adults with B-Cell Lymphoblastic Leukemia.
- Authors
- Maude SL, Laetsch TW, Buechner J, Rives S, Boyer M, Bittencourt H, et al.
- Journal
- The New England journal of medicine
- Type
- Clinical Trial, Phase II, Journal Article, Multicenter Study, Research Support, Non-U.S. Gov't
- PMID
- 29385370
Original abstract
BACKGROUND: In a single-center phase 1-2a study, the anti-CD19 chimeric antigen receptor (CAR) T-cell therapy tisagenlecleucel produced high rates of complete remission and was associated with serious but mainly reversible toxic effects in children and young adults with relapsed or refractory B-cell acute lymphoblastic leukemia (ALL). METHODS: We conducted a phase 2, single-cohort, 25-center, global study of tisagenlecleucel in pediatric and young adult patients with CD19+ relapsed or refractory B-cell ALL. The primary end point was the overall remission rate (the rate of complete remission or complete remission with incomplete hematologic recovery) within 3 months. RESULTS: For this planned analysis, 75 patients received an infusion of tisagenlecleucel and could be evaluated for efficacy. The overall remission rate within 3 months was 81%, with all patients who had a response to treatment found to be negative for minimal residual disease, as assessed by means of flow cytometry. The rates of event-free survival and overall survival were 73% (95% confidence interval [CI], 60 to 82) and 90% (95% CI, 81 to 95), respectively, at 6 months and 50% (95% CI, 35 to 64) and 76% (95% CI, 63 to 86) at 12 months. The median duration of remission was not reached. Persistence of tisagenlecleucel in the blood was observed for as long as 20 months. Grade 3 or 4 adverse events that were suspected to be related to tisagenlecleucel occurred in 73% of patients. The cytokine release syndrome occurred in 77% of patients, 48% of whom received tocilizumab. Neurologic events occurred in 40% of patients and were managed with supportive care, and no cerebral edema was reported. CONCLUSIONS: In this global study of CAR T-cell therapy, a single infusion of tisagenlecleucel provided durable remission with long-term persistence in pediatric and young adult patients with relapsed or refractory B-cell ALL, with transient high-grade toxic effects. (Funded by Novartis Pharmaceuticals; ClinicalTrials.gov number, NCT02435849 .).