Safety and Efficacy of Blinatumomab- Real World Data

Background: Despite improvement in survival of newly diagnosed adult ALL, the results of relapsed/refractory disease are still poor, with long term survival of Methods: Data from adult patients with B-ALL/B-LBL treated with blinatumomab in 4 hospitals in Israel was collected. Blinatumomab was given at the standard dose of 9 mcg/day in the first week of the first cycle, and 28 mcg/day thereafter for 28 days cycles, repeated every 6 weeks. Safety data including cytokine release and neurological symptoms was collected. Efficacy outcome included overall and complete response rates, overall survival, and leukemia free survival. Results: 13 patients are included in this analysis, median age 51.6 years (range 28.9-80.3) 7 male and 6 females. Diagnoses were B-ALL in 10, Ph+ B-ALL in 2, and B-LBL in 1 patient. Median time from diagnosis to blinatumomab treatment was 9.8 months (range 3.4-26.3), and 12/13 patients received blinatumomab for hematological relapse with 1 patient receiving treatment due to severe fungal infection and inability to continue standard chemotherapy or proceeding to SCT. Four patients (30.7%) received blinatumomab after allogeneic SCT. Three patients (23%) had CNS disease at the time of relapse. Blinatumomab was given as first salvage in 7, and after prior salvage in 6 patients. Median number of blinatumomab cycles were 1 (range 1-6), and patients spent on average 18.9 days in-hospital, and 18.8 days as outpatients during the treatment period. Response was evaluable in 12 patients with 5/12 patients achieving CR and 1 patient maintaining a previously achieved CR. CR was achieved in 2/2 Ph+ ALL patients, 1/4 patients relapsing after SCT and 1/3 patients with CNS disease at relapse. Following blinatumomab, 4 patients received allogeneic SCT, 1 in CR, 2 failing blinatumomab and entering CR after CAR-T therapy within a clinical trial and 1 after combination chemotherapy. Non-hematological side effects consisted of neurological symptoms in 1 (grade 2), GI symptoms in 1 (grade 3), infection in 1 (grade 3) and cytokine release syndrome in 3 patients (2-grade 2; 1-grade 4). At a median follow up of 13.3 months (range 1-20.6), 8 (62%) patients are alive, 6 (46%) in CR. Reasons for death included infection in 3 and disease progression in 2 patients. No patient died during blinatumomab administration. Median LFS is 8.7 months and median OS was not reached. Conclusions: The current cohort show a slightly higher CR rate and similar OS compared to the TOWER and ALCANTARA trials. Treatment with blinatumomab was safe, with manageable toxicity profiles. This, however, was achieved at a cost of prolonged hospitalizations in the majority of patients. Disclosures Ofran:Novartis: Other: Served on a Novartis advisory board.