Pfizer (PFE 0.23%) announced today a successful phase 2 trial of its breast cancer drug Palbociclib, which had shares up 2.5% on the news. "We are delighted with the final data, which suggests the potential for Palbociclib to transform the standard of care," Pfizer announced. The company could file for accelerated approval in March, which would potentially mean approval this year.

In this video, Motley Fool health-care analyst David Williamson looks at the competition in this space, the potential market for Pfizer's new drug, and one secret winner that stands to benefit here.