Additional Relevant Details In the Phase I study, presented by lead investigator Jae H. Park, M.D., of Memorial Sloan Kettering Cancer Center, 51 adult patients with relapsed or refractory (r/r) acute lymphoblastic leukemia (ALL) were treated with either cyclophosphamide or fludarabine/cyclophosphamide followed by an infusion of JCAR015. At the time of treatment, 31 patients had morphologic disease burden and 20 patients had minimal disease burden. Median study follow-up was 8.5 months. Key results include:

• Complete response (CR) was observed in 23/30 (77%) patients with morphologic disease and in 18/20 (90%) patients with minimal disease.
• In patients who achieved a CR and had adequate evaluation for minimal residual disease by flow cytometry or polymerase chain reaction, complete molecular remission was observed in 19/21 (90%) patients with morphologic disease and in 14/18 (78%) patients with minimal disease.
• Median overall survival (OS) for patients with minimal disease treated with JCAR015 was not reached, and that for morphologic patients treated with JCAR015 was 9 months; median OS follow-up for all patients was 13 months.
• Durable responses and survival observed in patients who received JCAR015 were comparable between groups that received a subsequent stem cell transplant and those that did not.
• Severe cytokine release syndrome (sCRS) was observed in 14/51 (27%) patients and Grade 3 or higher neurotoxicity was observed in 15/51 (29%) patients. For patients with minimal disease, 1/20 (5%) patients experienced sCRS and 4/20 (20%) patients had Grade 3 or higher neurotoxicity.