PS955 FEASIBLE OUTCOME OF BLINATUMOMAB FOLLOWED BY ALLOGENEIC HEMATOPOIETIC CELL TRANSPLANTATION FOR ADULTS WITH RELAPSED OR REFRACTORY PHILADELPHIA-NEGATIVE ACUTE LYMPHOBLASTIC LEUKEMIA

Abstract

Background: Additional salvage regimens are burdensome for relapsed/refractory acute lymphoblastic leukemia (ALL) patients (pts) due to therapy-associated toxicities, which may affect quality of life with poor efficacy. In INO-VATE (Kantarjian et al, NEJM 2016), pts receiving inotuzumab ozogamicin (InO) vs standard chemotherapy (SC) had significantly greater remission rates and longer overall survival; after study treatment discontinuation, overall fewer subsequent induction/salvage therapies (STs, mainly burdensome chemotherapies) were used in the InO group vs SC. Aims: To investigate the treatment of InO on the time to the first ST (TST) in the INO-VATE trial. Methods: Study design was published. Adults with CD22+ ALL who were due to receive 1st or 2nd salvage treatment were randomized 1:1 to InO (n = 164) or SC (n = 162). TST was time from randomization to the start of the first ST. Pts who did not receive any ST were censored. Data cutoff: Jan 4, 2017. Results: Fewer InO pts had ST vs SC pts (Table). Among the censored pts, 83/108 (76.9%) in the InO vs 54/69 (78.3%) in the SC group died, 23/108 (21.3%) vs 5/69 (7.2%) were alive at the end of the study, and 2/108 (1.9%) vs 10/69 (14.5%) were no longer being followed for survival. TST was longer in pts receiving InO vs SC. Overall median (95% CI) TST was 18.8 (14.7–NA) vs 3.9 (2.4–5.1) months; hazard ratio (HR) = 0.34, 97.5% CI: 0.23–0.49, 1-sided P < 0.0001. For pts (InO: 85, SC: 126) who never received hematopoietic stem cell transplantation (HSCT) on study, fewer InO pts had ST vs SC pts; TST was significantly longer in InO vs SC. For pts (InO: 70, SC: 18) who had HSCT directly after salvage, TST was extended in InO vs SC.Summary/Conclusion: In this study, treatment with InO provided the benefit of extended TST, effectively allowing patients a longer time period until an ST was needed in both patients who proceeded to as well as those who did not proceed to HSCT.