Tisagenlecleucel leads to high rates of durable remission among pediatric and young adult patients with relapsed or refractory (R/R) B-cell acute lymphoblastic leukemia (ALL), according to a study published in The New England Journal of Medicine.
A previous single-site trial showed that patients with R/R B-cell ALL treated with tisagenlecleucel achieved complete remission rates of 93%, leading investigators to further expand the scope of the study.
For this multisite, nonrandomized phase 2 study, researchers assigned 92 patients between the ages of 3 and 21 years to receive a single infusion of tisagenlecleucel. Eligible patients had at least 5% lymphoblasts in bone marrow at screening, and patients previously treated with anti-CD19 therapies were excluded. The median follow-up was 13.1 months.
At time of interim analysis, 75 patients had evaluable data. The 3-month overall remission rate was 81%, and all patients responsive to therapy were negative for minimal residue disease as confirmed by flow cytometry.
Event-free survival was 73% and 50% at 6 months and 12 months, respectively, and overall survival rates were 90% at 6 months and 76% at 12 months. The median duration of remission was not evaluable at the time of analysis.
Seventy-three percent of patients experienced grade 3 to 4 suspected treatment-related adverse events, most notably cytokine release syndrome (CRS), which occurred in 77% of patients. Of the patients who developed CRS, 48% were treated with tocilizumab. Forty percent of patients experienced neurologic events and were managed with supportive care; no cases of cerebral edema were observed.
The authors concluded that “tisagenlecleucel produced high remission rates and durable remissions without additional therapy in high-risk pediatric and young adult patients with relapsed or refractory B-cell ALL. The risks associated with tisagenlecleucel are substantial, leading to ICU-level care in some cases, but were mitigated in most patients with supportive measures and cytokine blockade.”
Maude SL, Laetsch TW, Buechner J, et al. Tisagenlecleucel in children and young adults with B-cell lymphoblastic leukemia [published online February 1, 2018]. N Eng J Med. doi: 10.1056/NEJMoa1709866