Chronic Myelogenous Leukemia Drug Gains Accelerated Approval

Yesterday, the FDA granted accelerated approval to bosutinib (Bosulif) for the treatment of patients with newly-diagnosed chronic phase (CP) Philadelphia chromosome positive (Ph+) chronic myelogenous leukemia (CML), according to a press release.

The approval was based on positive findings from a clinical trial that included 487 patients with Ph+ newly-diagnosed CP CML. Patients were randomized to receive bosutinib 400-mg or imatinib 400-mg once per day.

The primary efficacy outcome was major molecular response (MMR) at 1 year, which was defined ≤0.1% BCR ABL ratio—an oncogenic gene fusion—on international scale with a minimum of 3000 ABL transcripts, according to the release.

The researchers found that MMR at 1 year was 47.2% among patients treated with bosutinib and 36.9% among those treated with imatinib, according to the FDA.

The most common adverse reactions among newly-diagnosed patients are diarrhea, nausea, thrombocytopenia, rash, increased alanine aminotransferase, abdominal pain, and increased aspartate aminotransferase.

In 2012, the FDA granted approval to bosutinib for the treatment of patients with chronic, accelerated, or blast phase Ph+ CML that is resistant or intolerant to prior treatment, according to the FDA.

The application for CP Ph+ CML was previously granted priority review and orphan drug designation. Under these approval pathways, post-approval studies are required, according to the FDA.