Pfizer Announces Phase 3 Results of Investigational Compound Bosutinib

Pfizer Inc.announced that a significantly higher proportion of patients with newly diagnosed chronic myeloid leukemia who were treated with bosutinib (39 percent) experienced a major molecular response (MMR), a secondary endpoint, compared with patients treated with imatinib (26 percent) in the intent-to-treat (ITT) population (p=0.002). However, the study did not meet its primary endpoint of superior complete cytogenetic response (CCyR) rate at one year versus imatinib (70 percent vs. 68 percent, respectively, [p=0.601]), in the ITT population. These results are from a Phase 3 study of the investigational compound bosutinib as a first-line treatment in patients with Philadelphia chromosome positive (Ph+) chronic myeloid leukemia (CML), called the Bosutinib Efficacy and safety in chronic myeloid LeukemiA [BELA] study. These data were presented at an oral presentation at the 52nd Annual Meeting of the American Society of Hematology