Palbociclib's Role in Endocrine-Resistant Breast Cancer

“Palbociclib (Ibrance, Pfizer), the first CDK4/6 inhibitor to be approved for the treatment of breast cancer, has been welcomed by experts for its role in improving outcomes in patients with endocrine-resistant breast cancer.

“The drug should a significant improvement in progression-free survival (PFS) when it was added to fulvestrant (Faslodex, AstraZeneca) in the phase 3 PALOMA 3 trial, as reported recently by Medscape Medical News. The addition of palbociclib to fulvestrant increased median PFS to 9.2 months in patients with estrogen receptor (ER)–positive/HER2-negative endocrine-resistant breast cancer compared with 3.8 months in the placebo-fulvestrant group (P < .001).

“The overall survival data are still immature.

“The full results have now been published in print in the July 16 issue of the New England Journal of Medicine.