On February 19th, 2016, the U.S. Food and Drug Administration (FDA) approved palbociclib (Ibrance, Pfizer) for use in combination with fulvestrant (Faslodex, AstraZeneca) for the treatment of women with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced or metastatic breast cancer (MBC) with disease progression following endocrine therapy. The approval was based on the results of a randomized, double-blind, placebo-controlled trial conducted in 521 pre- and postmenopausal women with HR-positive, HER2-negative advanced or MBC. Patients were randomized (2:1) to receive palbociclib plus fulvestrant (n=347) or placebo plus fulvestrant (n=174). The primary endpoint was investigator assessed progression-free survival (PFS). A statistically significant and clinically meaningful improvement in PFS (9.5 vs. 4.6 months) was observed in patients receiving palbociclib plus fulvestrant [HR 0.46; 95% CI: 0.36-0.59; p<0.0001]. Safety data confirmed the known adverse reaction profile of palbociclib. The most common adverse reactions (>20%) in patients treated with palbociclib were neutropenia, leukopenia, infections, fatigue, nausea, anemia, stomatitis, headache, diarrhea, and thrombocytopenia. This approval was granted in the context of a prior accelerated approval for palbociclib in combination with letrozole in patients with HR-positive, HER2-negative advanced breast cancer as initial endocrine based therapy.
- Received April 20, 2016.
- Revision received June 1, 2016.
- Accepted June 7, 2016.
- Copyright ©2016, American Association for Cancer Research.