Study of Efficacy and Safety of Reinfusion of Tisagenlecleucel in Pediatric and Young Adult Patients With Acute Lymphoblastic Leukemia (ALL)

This was a multi-center Phase II study investigating the efficacy and safety of reinfusion of tisagenlecleucel in pediatric and young adult patients with acute lymphoblastic leukemia (ALL) who were treated with tisagenlecleucel and experience B cell recovery.

This trial was a phase II, open label, multi-center trial to determine the efficacy and safety of tisagenlecleucel re-infusion in pediatric and adolescent young adult (AYA) patients with acute lymphoblastic leukemia (ALL) experiencing loss of B cell aplasia. Loss of B-cell aplasia is defined as: peripheral blood (PB) absolute B lymphocyte count ≥ 50/µL, OR PB B lymphocyte ≥ 10% of the total lymphocytes. B-cell aplasia is defined as PB absolute B lymphocyte count \<50/µL. The study had the following phases for all patients: Screening, Treatment and Follow-up. The total duration of the study was about 12 months. After tisagenlecleucel re-infusion, efficacy was assessed at months 1, 3, 6, and End of Study at which time blood samples were obtained. The study stopped early due to slow enrollment into the trial. The rate of enrollment made the trial no longer feasible to continue. The patients were able to voluntarily withdraw from the study for any reason, at any time. Patients who received commercial tisagenlecleucel had to be followed for up to 15 years post-infusion. Patients could have been followed under the Center for International Blood and Marrow Transplant Research (CIBMTR) cellular therapy registry if consented for participation. For patients who do not provide consent for participation in the Center for International Blood and Marrow Transplant Research (CIBMTR) registry, adverse events were to be reported for 15 years or until the patient enrolls in the registry.