FDA Approves Pfizer’s IBRANCE for HR+/HER2+ Metastatic Breast Cancer

The FDA has approved Pfizer‘s IBRANCE (palbociclib) in combination with trastuzumab, with or without pertuzumab, and endocrine therapy for the maintenance treatment of HR+/HER2+ locally advanced or metastatic breast cancer following induction treatment. IBRANCE becomes the only CDK4/6 inhibitor indicated for HR+ metastatic breast cancer regardless of HER2 status.

The approval is based on the Phase 3 PATINA trial, which demonstrated a 24% reduction in the risk of disease progression or death when IBRANCE was added to anti-HER2 and endocrine therapies compared to anti-HER2 and endocrine therapies alone. The trial enrolled 518 patients across an international academic collaboration led by Alliance Foundation Trials with six cancer research groups across the U.S., France, Germany, Italy, Spain, Portugal, Australia, and New Zealand. Results were published in the New England Journal of Medicine.

Approximately 10% of all breast cancers are HR+/HER2+, sometimes called double-positive or triple-positive. This subtype has historically had limited research focus, and PATINA is the first registrational study to explore CDK4/6 inhibition in this population.

“Resistance to dual anti-HER2 and endocrine therapy remains a central clinical challenge for patients with HR+, HER2+ metastatic breast cancer – even after an excellent response to initial treatment,” said principal investigator Dr. Otto Metzger of Dana-Farber Cancer Institute. “The addition of IBRANCE in the maintenance phase can meaningfully extend the time patients go without their disease progressing.”

Since its initial approval in 2015, IBRANCE has been prescribed to more than 900,000 patients and approved in over 100 countries.