Alliance Foundation Trials, LLC announced on June 24 that the U.S. Food and Drug Administration has approved palbociclib in combination with trastuzumab, with or without pertuzumab, and endocrine therapy for adult patients with hormone receptor–positive (HR+), human epidermal growth factor receptor 2–positive (HER2+) locally advanced or metastatic breast cancer following induction treatment.
The approval is based on results from the phase III PATINA trial (AFT-38), which showed that adding the CDK4/6 inhibitor palbociclib to standard first-line maintenance therapy significantly prolongs progression-free survival. The study demonstrated a 24% reduction in the risk of progression or death compared with standard therapy alone.
Approximately 10% of all breast cancers are HR+, HER2+, sometimes referred to as double-positive or triple-positive breast cancer. Despite advances in treatment, resistance to anti-HER2 and endocrine therapies remains a challenge, highlighting the need for new therapeutic approaches.
"PATINA answered an important clinical question and established that the addition of palbociclib to standard maintenance therapy can significantly extend progression-free survival in this patient population," said Otto Metzger, MD, Principal Investigator of PATINA and Associate Medical Director of International Strategic Initiatives at Dana-Farber Cancer Institute. "This approval translates those findings into a new treatment option for patients and provides clinicians with another tool to help manage a complex and challenging disease."
The PATINA trial evaluated whether adding palbociclib after four to eight cycles of induction chemotherapy could delay disease progression when combined with anti-HER2 therapy and endocrine therapy. Results were previously published in the New England Journal of Medicine and presented at the 2024 San Antonio Breast Cancer Symposium. Patients receiving palbociclib experienced an improvement in median progression-free survival from 29.1 months to 44.3 months, with no new safety signals reported.
"The AFT Statistics and Data Center coordinated a centralized clinical database for this international trial, enabling a timely final PFS analysis," said Sumithra Mandrekar, PhD, faculty statistician and AFT SDC program director. From June 2017 through July 2021, the trial enrolled 518 patients across multiple sites worldwide who were randomly assigned either palbociclib plus anti-HER2/endocrine therapy or anti-HER2/endocrine therapy alone.
