Bosutinib misses BELA primary endpoint

Pfizer Inc. (NYSE:PFE) said bosutinib missed the primary endpoint but met the secondary endpoint in the Phase III BELA trial to treat newly diagnosed chronic myelogenous leukemia (CML). Bosutinib did not significantly improve complete cytogenetic response (CCyR) rate at one year, the primary endpoint, vs. Gleevec imatinib (70% vs. 68%, p=0.601). However, the dual inhibitor of BCR-ABL and Src kinase did significantly improve major molecular response (MMR) rate at one year vs. Gleevec (39% vs. 26%, p=0.002). The open-label, international trial enrolled 502 patients with newly diagnosed Philadelphia chromosome-positive (Ph+) chronic phase CML.

Pfizer said 25% of bosutinib patients experienced serious adverse events compared to 14% of Gleevec patients. Bosutinib patients also experienced more adverse events leading to discontinuation than those receiving Gleevec (19% vs. 6%). ...