The FDA has approved the use of Ibrance (palbociclib) together with trastuzumab, with or without pertuzumab, plus hormone therapy as a maintenance treatment for adults with hormone receptor–positive, HER2-positive advanced or metastatic breast cancer after initial treatment.
The approval is based on results from the phase 3 PATINA Trial, which enrolled 518 patients. The study showed that adding palbociclib significantly delayed disease progression compared with standard maintenance therapy alone. At 24 months, 65.2% of patients receiving palbociclib remained progression-free, compared with 55.3% in the standard treatment group. Patients receiving palbociclib also experienced longer-lasting treatment responses, with a median response duration of 44.9 months versus 30.8 months. Overall survival results are still being evaluated.
The recommended dose of palbociclib is 125 mg once daily for 21 days, followed by a 7-day break. Common side effects include low white blood cell counts (neutropenia), diarrhea, and fatigue. The drug label also carries warnings about serious lung problems and potential harm to an unborn baby.