Palbociclib remains a bright spot in Pfizer's ($PFE) pipeline. The pharma giant reported today that it had cut short a Phase III study of the drug, recently approved under an accelerated pathway as Ibrance, after clearly demonstrating that it had met its primary endpoint: progression-free survival with a combination of Ibrance plus fulvestrant in women with hormone receptor positive, human epidermal growth factor receptor 2 negative metastatic breast cancer. "The results of this trial are especially important because they help us understand the potential of Ibrance to improve outcomes in patients with this difficult to treat cancer. We're gratified to be able to stop the trial early and are engaging in discussions with health authorities regarding a regulatory path forward," said Dr. Mace Rothenberg, chief medical officer for Pfizer Oncology. Release | More from FiercePharma