The U.S. Food and Drug Administration (FDA) approved blinatumomab for pediatric and adolescent patients with Philadelphia chromosome-negative relapsed/refractory B-cell precursor acute lymphocytic leukemia (ALL).
The approval was based on the results of a single-arm, open-label, multicenter, dose-finding phase I/II study, in which patients receiving blinatumomab achieved complete remission (CR) within the first two cycles of treatment (the study's primary endpoint).
A total of 93 pediatric and adolescent patients (<18 years) who had refractory disease relapsed at least twice, or relapsed after an allogeneic hematopoietic cell transplantation were included in the study. During phase I, the researchers proposed a stepwise dosing of 5/15 Î¼g/m2 per day.
During phase I, the CR rate was approximately 32 percent among 41 patients who were enrolled. Of those patients, 77 percent reached a minimum residual disease (MRD)-negative state.
The median relapse-free survival (RFS) was 8.3 months, and the median overall survival (OS) was 5.7 months.
Among 39 patients enrolled in the phase II study, the CR rate was 31 percent (n=12). Of those patients, 42 percent were MRD-negative. The median RFS was 5.6 months, and the median OS was 4.3 months.
The most common treatment-related grade â‰¥3 adverse events included anemia, thrombocytopenia, febrile neutropenia, hypokalemia, and neutropenia.
Patients are undergoing continued assessment for long-term efficacy outcomes.
Source: Amgen news release, September 1, 2016.