Bosulif Superior to Imatinib for First-line Chronic Phase Ph+ CML Therapy

New data from the phase 3 BFORE trial suggests Bosulif (bosutinib; Pfizer Inc) is superior to imatinib as a first-line treatment for patients with chronic phase Philadelphia chromosome positive (Ph+) chronic myeloid leukemia (CML).

Based on the results of the BFORE trial, Pfizer announced in a press release that it will now pursue action with the FDA and other regulatory authorities to make Bosulif available for Ph+ CML patients as a first-line treatment option.

“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,” Mace Rothenberg, MD, chief development officer of Oncology at Pfizer Global Product Development, said in a press release. “The positive outcome of the BFORE study represents a key step in potentially broadening treatment options for patients in the first-line setting.” 

Bosulif is an oral, once-daily tyrosine kinase inhibitor taken at 500 mg with food. It was approved in the United States in September 2012 to treat adult patients with Ph+ CML who are resistant or intolerant of prior therapy. In Europe, Bosulif was granted conditional marketing authorization in March 2013.

In the BFORE study, investigators randomly assigned first-line Bosulif or imatinib to 536 study particpants recruited at multiple sites in North America, Asia, and Europe. At 12 months, the major molecular response rate of Bosulif was superior to that of imatinib, and no new or unexpected adverse safety issues were identified by the investigators, according to the press release.

“This is an important milestone for Pfizer’s emerging hematology portfolio as we work to develop new treatments for patients with acute and chronic hematologic malignancies,” Dr Rothenberg said.

Funding and conduct for the clinical trial was provided by Avillion LLP under an exclusive, collaborative development agreement signed with Pfizer in 2014. In the press release, Allison Jeynes-Ellis, MD, CEO of Avillion, praised the partnership between the two companies, noting that their success “is good news for CML patients because additional first-line treatment options allow physicians to tailor therapy based on individual patient considerations.” —Dave Muoio