Predictors of prolonged benefit from palbociclib plus fulvestrant in women with endocrine-resistant hormone receptor-positive/human epidermal growth factor receptor 2-negative metastatic breast cancer in PALOMA-3

This exploratory analysis demonstrates that some patients with endocrine-resistant MBC derive significant and prolonged benefit when treated with palbociclib-fulvestrant, with fewer patients experiencing similar efficacy with placebo-fulvestrant. The current analysis did not identify specific molecular or clinical factors prognostic of long-term benefit with palbociclib-fulvestrant (ClinicalTrials.gov, NCT01942135).