The following is a summary of “Single agent subcutaneous blinatumomab for advanced acute lymphoblastic leukemia,” published in the February 2024 issue of Hematology by Jabbour et al.

Researchers conducted a retrospective study to assess whether subcutaneous  (SC)  administration of blinatumomab, a BiTE ^® (bispecific T-cell engager) molecule engaging CD3⁺ T-cells to lyse CD19⁺ target cells, offers comparable efficacy with enhanced convenience.

They conducted an expansion phase within a multi-institutional phase 1b trial, where heavily pretreated adults with relapsed/refractory B-cell acute lymphoblastic leukemia (R/R B-ALL) were administered SC blinatumomab at two dosing regimens, 250 μg once daily (QD) during week 1 and 500 μg three times weekly (TIW) thereafter (250 μg/500 μg), or500 μg QD during week 1 and 1000 μg TIW thereafter (500 μg/1000 μg). Within two cycles, the primary endpoint achieved complete remission/complete remission with partial hematologic recovery (CR/CRh).

The results showed 29 patients (September 15, 2023), 14 at the 250 μg/500 μg dose and 13 at the 500 μg/1000 μg dose, with excluded data from two ineligible patients. Following two cycles, CR/CRh was achieved by 85.7% (12 /14) of patients on the 250 μg/500 μg dose, with 75.0% (9 patients) testing MRD-negative (MRD; <10 ^-4 leukemic blasts). Among those on the 500 μg/1000 μg dose, 92.3% (12 /13) attained CR/CRh, with all 12 patients (100.0%) being MRD-negative. No treatment-related grade 4 cytokine release syndrome (CRS) or neurologic events (NEs) were reported; all instances of grade 3 CRS and NEs responded well to standard-of-care management, interruption, or discontinuation.

Investigators concluded that SC blinatumomab demonstrated potent efficacy, achieving minimal residual disease negativity and a tolerable safety profile in pretreated adults with R/R B-ALL.

Source: onlinelibrary.wiley.com/doi/full/10.1002/ajh.27227