Subcutaneous blinatumomab in patients with R/R Ph+ B-ALL: Phase I/II study results

Results from a phase I/II study (NCT04521231) evaluating subcutaneous (SC) blinatumomab in 16 patients with relapsed/refractory (R/R) Philadelphia chromosome-positive (Ph+) B-cell acute lymphoblastic leukemia (B-ALL) were presented by Elias Jabbour at the European Hematology Association (EHA) 2026 Congress, June 11–14, 2026, Stockholm, SE. The primary endpoint was complete remission (CR) / CR with partial hematologic recovery (CRh). Secondary endpoints included CR with incomplete hematologic recovery (CRi), measurable residual disease response (MRD), hematopoietic stem cell transplantation (HSCT) status, overall survival (OS), and safety and tolerability.

Key data: With a median of 2.0 blinatumomab cycles, the overall CR/CRh rate was 81.3%, with MRD negativity achieved in 76.9% of patients. CR/CRh rates in the 250 μg / 500 μg (n = 8) and 500 μg / 1,000 μg (n = 8) cohorts were 75.0% and 87.5%, respectively. The overall CR/CRh/CRi rate was 93.8%, with MRD negativity achieved in 80.0% of patients. At a median follow-up of 16.3 months, median OS was 19.4 months (95% confidence interval [CI], 3.9–not estimable [NE]). Following blinatumomab treatment, 31.3% of patients proceeded to HSCT. No new safety signals were observed.

Key learning: Blinatumomab SC demonstrated high response rates and encouraging survival outcomes in heavily pretreated patients with R/R Ph+ B-ALL.