Shorter Duration of Blinatumomab Administration to 14 Days Has Same Efficacy and Safety Profile in Treatment of Relapsed/Refractory B-Cell Precursor Acute Lymphoblastic Leukemia: A Retrospective Single-Center Study.

Introduction: Treatment of patients with relapsed/refractory B-cell precursor acute lymphoblastic leukemia (r/r BCP-ALL) remains a significant clinical challenge. Many new strategies are changing the treatment landscape of r/r BCP-ALL in recent years. Blinatumomab has improved outcomes in r/r BCP-ALL, though high treatment costs and extended hospital stays are significant concerns. We considered that shortening the duration of blinatumomab administration during induction therapy might solve these problems.

Methods: We retrospectively analyzed 19 patients with r/r BCP-ALL treated with different durations of blinatumomab, where 10 patients received blinatumomab for 14 days (Bli 14D group) and 9 received it for a longer duration (LT group, 21-28 days).

Results: The overall response rate (ORR) was 63.2% (12/19) of patients in total, and the ORRs in 14D and LT groups were almost the same (60% and 66.6%, respectively). The median overall survival was not reached in either groups. The median event-free survival time was 4.1 months in LT group and not reached in D14 group. The most common adverse events were consistent with previous reports, including cytokine release syndrome, neurologic toxicity, and hematological toxicity.

Conclusion: A 14-day blinatumomab administration may be a promising and well-tolerated regimen in r/r BCP-ALL, offering the same ORR and survival rates.