Single agent subcutaneous blinatumomab for advanced acute lymphoblastic leukemia

Area of Science:

• Oncology
• Immunology
• Pharmacology

Background:

• Blinatumomab is a bispecific T-cell engager (BiTE®) that targets CD19+ B-cells.
• Relapsed/refractory B-cell acute lymphoblastic leukemia (R/R B-ALL) has limited treatment options.
• Subcutaneous (SC) administration offers potential for improved patient convenience.

Purpose of the Study:

• To evaluate the efficacy and safety of SC blinatumomab in adults with R/R B-ALL.
• To assess complete remission/complete hematologic recovery (CR/CRh) and measurable residual disease (MRD) negativity rates.
• To determine the tolerability of SC blinatumomab administration.

Main Methods:

• Phase 1b multi-institutional trial (NCT04521231) in heavily pretreated adults with R/R B-ALL.
• Two SC blinatumomab dosing regimens were evaluated: 250 μg QD/500 μg TIW and 500 μg QD/1000 μg TIW.
• Primary endpoint: CR/CRh within two cycles; secondary endpoints included MRD negativity and safety.

Main Results:

• High CR/CRh rates observed: 85.7% (250/500 μg) and 92.3% (500/1000 μg).
• Excellent MRD-negativity rates: 75.0% (250/500 μg) and 100.0% (500/1000 μg).
• No treatment-related grade 4 cytokine release syndrome (CRS) or neurologic events (NEs); grade 3 events were manageable.

Conclusions:

• SC blinatumomab demonstrates high efficacy in R/R B-ALL patients.
• High rates of MRD negativity achieved with SC blinatumomab.
• SC blinatumomab offers an acceptable safety profile and convenient administration for R/R B-ALL treatment.