Pfizer’s IBRANCE wins FDA approval as a maintenance option in HR+, HER2+ metastatic breast cancer

Pfizer has recently confirmed that the US FDA has cleared IBRANCE, which is used alongside trastuzumab with or without pertuzumab and endocrine therapy, for maintaining treatment in adults with hormone receptor-positive, human epidermal growth factor receptor 2-positive locally advanced or metastatic breast cancer after completing induction treatment. Positive findings from the Alliance Foundation Trials-sponsored Phase 3 PATINA study formed the cornerstone of the submission.

“Over the past decade, IBRANCE has helped transform metastatic breast cancer treatment, establishing CDK4/6 inhibition as a cornerstone of care,” said Aamir Malik, Chief U.S. Commercial Officer and Executive Vice President, Pfizer. “With today’s FDA approval, IBRANCE becomes the first and only CDK4/6 inhibitor indicated for patients with HR+ metastatic breast cancer regardless of HER2 status, extending its impact to patients who continue to face challenges with treatment resistance. This milestone strengthens confidence in IBRANCE as a CDK4/6 inhibitor backbone across combination regimens, reflecting Pfizer’s ongoing leadership in delivering meaningful advances for people with breast cancer.”

Incorporating IBRANCE into a maintenance regimen alongside anti-HER2 treatment and endocrine therapy lowered the chance of disease worsening or death by nearly a quarter compared with anti-HER2 and endocrine therapy given alone. Throughout the PATINA trial, IBRANCE’s tolerability characteristics held consistent with its long-established profile. Haematologic events, notably declines in white blood cell and neutrophil counts, featured most prominently among reported adverse reactions, while diarrhoea, infections, stomatitis, and fatigue also arose, though rarely with severity beyond mild to moderate. Alliance Foundation Trials had previously shared the complete trial data through publication in the New England Journal of Medicine, with a presentation at the 2024 San Antonio Breast Cancer Symposium also forming part of the wider scientific disclosure.

“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 Otto Metzger, M.D., principal investigator of the trial for Alliance Foundation Trials and Medical Oncologist at the Dana-Farber Cancer Institute. “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.”

Around one in ten breast cancer diagnoses present with both hormone receptor positivity and HER2 positivity, a profile sometimes called double-positive or triple-positive breast cancer. This specific subtype has historically attracted comparatively little dedicated research within the metastatic setting, making PATINA the first registrational trial to examine the contribution CDK4/6 inhibition could make here.

Since entering the market in 2015, IBRANCE has established itself as a go-to first-line treatment for HR+, HER2-negative metastatic breast cancer, amassing a prescribing history spanning more than 900,000 patients across upwards of 100 countries.

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Related Topics and Keywords

breast cancer, HER2+ Metastatic Breast Cancer, ibrance, metastatic breast cancer, Pfizer