The US Food and Drug Administration (FDA) has approved Pfizer’s IBRANCE (palbociclib) in combination with trastuzumab, with or without pertuzumab, and endocrine therapy as a maintenance treatment for adults with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-positive (HER2+) locally advanced or metastatic breast cancer following induction treatment.
IBRANCE is an oral inhibitor of CDKs 4 and 6, key proteins involved in regulating the cell cycle that trigger cellular progression.
The approval is supported by results from the Phase 3 PATINA trial, sponsored by Alliance Foundation Trials (AFT).
The study showed that adding IBRANCE to anti-HER2 therapy (trastuzumab alone or with pertuzumab) and endocrine therapy reduced the risk of disease progression or death by 24 per cent compared with anti-HER2 and endocrine therapy alone.
Aamir Malik, chief US commercial officer and executive vice president at Pfizer, said IBRANCE has helped transform metastatic breast cancer treatment over the past decade by establishing CDK4/6 inhibition as a cornerstone of care.
He added that the latest FDA approval makes IBRANCE “the first and only CDK4/6 inhibitor indicated for patients with HR+ metastatic breast cancer regardless of HER2 status,” expanding treatment options for those facing resistance to existing therapies.
Otto Metzger, principal investigator of the PATINA trial for Alliance Foundation Trials and medical oncologist at Dana-Farber Cancer Institute, said resistance to dual anti-HER2 and endocrine therapy remains a major clinical challenge for patients with HR+, HER2+ metastatic breast cancer, even after a strong response to initial treatment.
“Based on the results from the PATINA study, the addition of IBRANCE in the maintenance phase can meaningfully extend the time patients go without their disease progressing. This approval gives oncologists a new, evidence-based option to optimize maintenance therapy for their patients with HR+, HER2+ disease,” he said.
HR+, HER2+ breast cancer—sometimes referred to as double-positive or triple-positive breast cancer—accounts for around 10 per cent of all breast cancer cases. Research in this subtype of metastatic breast cancer has historically been limited, making PATINA the first registrational study to evaluate the role of CDK4/6 inhibition in this patient group.
Since receiving its first approval in 2015, IBRANCE has become a standard first-line treatment for HR+, HER2-negative metastatic breast cancer and has been prescribed to more than 900,000 patients across over 100 countries.
