Bosutinib: Phase III data

The ongoing, open-label, international Phase III BELA trial in 502 patients with newly diagnosed Philadelphia chromosome-positive (Ph+) chronic phase CML showed that daily oral bosutinib missed the primary endpoint of significantly improving CCyR rate at 1 year vs. Gleevec imatinib (70% vs. 68%, p=0.601). Bosutinib did meet the secondary endpoint of significantly improving MMR rate at 1 year vs. Gleevec (39% vs. 26%, p=0.002). Additionally, 1.6% of patients treated with bosutinib progressed to an advanced phase of CML compared to 4% for Gleevec. Patients responding to bosutinib also achieved a CCyR faster than patients responding to Gleevec (13 vs. 25 weeks, p<0.001). The most common grade 3/4 adverse events were diarrhea and rash. Additionally, 25.4% of patients treated with bosutinib experienced serious adverse events compared to 13.5% for Gleevec. Bosutinib-treated patients also experienced more adverse events leading to discontinuation vs. Gleevec (19.4% vs. 5.6%). Patients received once-daily 500 mg oral bosutinib or 400 mg Gleevec. Data were presented at the American Society of Hematology meeting in Orlando. ...