On December 3, 2014, the U. S. Food and Drug Administration granted accelerated approval for blinatumomab for the treatment of Philadelphia chromosome-negative relapsed or refractory B-cell precursor acute lymphoblastic leukaemia (R/R ALL).

The approval was based on the achievement of durable complete remission and response with a reduction in minimal residual disease to less than 10-4 in a multicentre single-arm trial (Protocol MT103-211) that enrolled 185 patients with R/R ALL. Blinatumomab was administered by continuous infusion for 4 weeks of a 6-week cycle. 

In Protocol MT103-211, one in three patients with R/R ALL attained complete remission with two cycles of treatment with single-agent blinatumomab, and the response was durable. 

Furthermore, 31% of the patients in the study had a complete remission, with or without complete haematological recovery, but with reduction in minimal residual disease to <10-4.

Safety was evaluated in 212 patients with R/R ALL treated with blinatumomab. 

Blinatumomab is a bispecific CD19-directed CD3 T-cell engager that activates endogenous T cells when bound to the CD19-expressing target cell.  

Activation of the immune system results in release of inflammatory cytokines. Cytokine release syndrome, including life-threatening or fatal events, was reported in 11% of the patients.  

For patients weighing at least 45 kg, the recommended dose and schedule for blinatumomab is 9 mcg/day on days 1-7 and at 28 mcg/day on days 8-28 of the first 42-day cycle, and 28 mcg/day on days 1-28 in later cycles.

Full prescribing information, including clinical trial information, safety, dosing, drug-drug interactions, and contraindications is available from the FDA.

Source: Food and Drugs Administration.