Real-World Outcomes of Adult B-Cell Acute Lymphocytic Leukemia Patients Treated With Inotuzumab Ozogamicin

A real-world analysis of relapsed/refractory (RR) B-cell acute lymphocytic leukemia (ALL) patients who received inotuzumab ozogamicin has further endorsed its effectiveness, resulting in high response rates and good survival in RR B-cell ALL. patients. Although hepatotoxicity was the most common adverse event observed, a small proportion of patients had grade 3 or higher adverse events, most of which were effectively treated with supportive care. Background: Inotuzumab ozogamicin (InO) is an anti-CD22 monoclonal antibody-drug (calicheamicin) conjugate that has shown superior efficacy compared to conventional chemotherapy in relapsed/refractory (RR) B-cell acute lymphocytic leukemia (ALL) patients. We sought to find the safety and efficacy of InO in a real-world setting. Patients and Methods: A multicenter cohort analysis on 84 RR ALL patients who received InO outside of clinical trials was conducted to evaluate response and toxicity. Results: The median (range) age of patients at InO initiation was 50 (20-87) years. Forty patients (48%) had >= 3 therapies and 23 patients (27%) underwent allogeneic hematopoietic stem-cell transplantation (allo-HCT) before InO. The median (range) number of cycles of InO provided was 2 (1-6), and cumulative dose was 3.3 (1.8-9.3) mg/m(2) . Overall response rate (complete remission/complete remission with incomplete count recovery) was 63%; 44% had complete remission with minimal residual disease negativity. Twenty-three patients (27%) with response received allo-HCT. The median duration of response was 11.5 months and when censored at allo-HCT was not reached (51% in remission at 2 years). The median overall survival after InO was 11.6 months and when censored at time of allo-HCT was 13.6 months. The most common grade 3 or higher adverse events observed were transaminitis (16%), hyperbilirubinemia (5%), bleeding (4%), veno-occlusive disease (2%), and hyperglycemia (2%). In multivariate analysis, allo-HCT after InO did not retain favorable significance for duration of response (hazard ratio = 1.27; 95% confidence interval, 0.89-1.61; P = .2) or overall survival (hazard ratio = 1.10; 95% confidence interval, 0.37-3.25; P = .85). Conclusion: InO was well tolerated and had significant efficacy in RR B-cell ALL patients. (C) 2020 Elsevier Inc. All rights reserved.