Pfizer's bosutinib fails head-to-head showdown with Gleevec

With investors still digesting the news of Jeff Kindler's quick exit, Pfizer ($PFE) had yet another pivotal trial failure on its hands. This time around the bad news was about bosutinib, a cancer drug being studied in a head-to-head study with Gleevec as a treatment for chronic myeloid leukemia. Bosutinib failed to demonstrate a superior complete cytogenetic response when compared with Gleevec after a year of treatment. But researchers were happy to tout a better major molecular response profile, a secondary endpoint. And Pfizer says that despite the Phase III primary endpoint setback, it still has enough data in hand to head to regulators to seek an approval.

"We are encouraged by these data, as they demonstrate early and meaningful response to bosutinib in patients with newly diagnosed CML. Given the length of time these patients are treated for CML, we need more therapeutic options to choose from since each patient is different and has different needs," said Dr. Carlo Gambacorti-Passerini, a lead investigator of the BELA study. "Based on my experience with bosutinib, I feel it would be an important option for patients with CML."

Pfizer singled out bosutinib at the beginning of this year as one of its most promising late-stage oncology programs following the big merger with Wyeth. And it's determined to capitalize on the work.

"Based on the totality of evidence from the bosutinib clinical development program, we are actively engaged in discussions with regulatory authorities which we hope will enable Pfizer to offer a new treatment option for patients with CML," said Dr. Mace Rothenberg, senior vice president of clinical development and medical affairs for Pfizer's Oncology Business Unit.

- read the Pfizer release
- see the Bloomberg story