Positive results from PALOMA-2 trial of Ibrance (palbociclib) + letrozole for estrogen receptor-positive, human epidermal growth factor receptor 2-negative (ER+, HER2-) advanced or metastatic breast cancer- Pfizer

Pfizer announced positive top-line results from the Phase III PALOMA-2 trial for Ibrance (palbociclib), an oral, first-in-class inhibitor of cyclin-dependent kinases (CDKs) 4 and 6.1 The study met its primary endpoint by demonstrating an improvement in progression-free survival (PFS) for the combination of Ibrance plus letrozole compared with letrozole plus placebo in post-menopausal women with estrogen receptor-positive, human epidermal growth factor receptor 2-negative (ER+, HER2-) advanced or metastatic breast cancer who had not received previous systemic treatment for their advanced disease.

The PALOMA-2 trial provides confirmatory evidence for Ibrance in combination with letrozole in the first-line setting, which was first studied in the Phase II PALOMA-1 trial. These data will support additional planned global regulatory submissions and a request for conversion of the accelerated approval for Ibrance to regular approval in the U.S. Detailed efficacy and safety results from PALOMA-2 will be submitted for presentation at the American Society of Clinical Oncology (ASCO) 2016 Annual Meeting.

Comment: in August 2015, Pfizer filed a Marketing Authorization Application (MAA) with the European Medicines Agency (EMA) for Ibrance in combination with endocrine therapy for the treatment of HR+, HER2- advanced or metastatic breast cancer. The MAA was based on the results from the PALOMA-1 and PALOMA-3 trials.