Subcutaneous blinatumomab for relapsed/refractory ALL

At the 2025 American Society of Hematology (ASH) Annual Meeting, Prof Elias Jabbour, hematologist at The University of Texas MD Anderson Cancer Center, presented updated results from a phase 1b study evaluating subcutaneous blinatumomab in patients with relapsed or refractory acute lymphoblastic leukemia (R/R ALL). This dose-escalation study established the recommended phase 2 dose and assessed two expansion cohorts (250/500 mg and 500/1000 mg schedules). Blinatumomab was administered daily during week 1, followed by subcutaneous dosing three times weekly from week 2 onward, with treatment breaks between cycles.

Subcutaneous administration offers improved convenience compared with intravenous delivery and eliminates the need for continuous infusion. Importantly, however, it also demonstrated superior efficacy. Complete remission (CR/CRh) rates exceeded 70% across both dose cohorts, with minimal residual disease (MRD) negativity approaching 100% among responders. With extended follow-up beyond the initial report published in The Lancet Haematology earlier this year, the 12-month overall survival rate approximated 60% in both cohorts. These outcomes are markedly better than historical outcomes with intravenous blinatumomab, which achieves CR rates of approximately 40% and a median survival of approximately 7 months in this setting.

The agent showed robust activity in heavily pretreated patients, including those who had failed multiple other treatments, including CAR T-cell therapy. No new safety signals were observed, with rates of cytokine release syndrome (CRS) and immune effector cell–associated neurotoxicity syndrome (ICANS) consistent with prior reports. Finally, an analysis of overall survival among responders showed that subsequent allogeneic stem cell transplantation did not provide additional survival benefit.