Pfizer and partner Avillion have presented data from a late-stage study showing that Bosulif was better than Novartis' Gleevec as a first-line treatment for patients with chronic phase Philadelphia chromosome positive (Ph+) chronic myeloid leukemia.

The Phase III BEFORE study met its primary endpoint of major molecular response at 12 months, and no new or unexpected safety issues were identified, the drug giant noted, but released no specific data at this time.

Based on the findings, Pfizer said it plans to now work with regulatory authorities to seek expanded approval of Bosulif, which is currently approved for the treatment of chronic, accelerated, or blast phase Ph+ CML in patients who are resistant to or who cannot tolerate other therapies including Gleevec (imatinib).

"Since its approval, the efficacy and distinct tolerability profile of Bosulif has provided an important treatment option for patients with Ph+ CML who are resistant or intolerant to prior therapy. The positive outcome of the BFORE study represents a key step in potentially broadening treatment options for patients in the first-line setting," said Mace Rothenberg, MD, chief development officer, Oncology, Pfizer Global Product Development.

"This is an important milestone for Pfizer's emerging haematology portfolio as we work to develop new treatments for patients with acute and chronic haematologic malignancies."

Detailed efficacy and safety data from the study will be submitted for a future congress or peer-reviewed journal.