Pfizer issued the following announcement on June 25.
Pfizer today announced overall survival (OS) results from the Phase 3 PALOMA-3 trial, which evaluated IBRANCE® (palbociclib) in combination with fulvestrant compared to placebo plus fulvestrant in women with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) metastatic breast cancer whose disease has progressed after prior endocrine therapy. The results demonstrated a positive trend in the hazard ratio favoring the IBRANCE combination, although this trend did not reach statistical significance. Overall survival is a secondary endpoint of the PALOMA-3 trial and, as such, the trial design was not optimized to detect a statistically significant difference in OS.
“While the difference in overall survival narrowly missed the threshold for statistical significance – a high bar for any trial in this patient population – it is similar, in absolute terms, to the improvement in median progression-free survival previously demonstrated in this trial. We are encouraged by these results, which build on the compelling clinical benefit delivered by IBRANCE,” said Mace Rothenberg, M.D., chief development officer, Oncology, Pfizer Global Product Development. “IBRANCE in combination with endocrine therapy has transformed the treatment landscape for patients with HR+, HER2- metastatic breast cancer.”
PALOMA-3 met its primary endpoint of progression-free survival (PFS) at interim analysis and results were published in The New England Journal of Medicine in June 2015; updated PFS data were later presented at the 2016 San Antonio Breast Cancer Symposium. The trial demonstrated a statistically significant and clinically meaningful improvement in PFS for IBRANCE plus fulvestrant compared to placebo plus fulvestrant. PFS is a well-established measure of clinical benefit in metastatic breast cancer trials. IBRANCE in combination with fulvestrant has been approved in more than 80 countries around the world based on the PFS demonstrated in PALOMA-3.
“The duration of the survival in hormone receptor-positive metastatic breast cancer patients, and the potential for subsequent therapies to confound overall survival outcomes, make demonstrating statistically significant improvement in overall survival extremely difficult,” said Nicholas Turner, M.D., Ph.D., professor of molecular oncology at The Institute of Cancer Research, London, and consultant medical oncologist at The Royal Marsden NHS Foundation Trust, as well as principal investigator of the PALOMA-3 trial. “The results from this overall survival analysis support the strong progression-free survival results from PALOMA-3 and, while not statistically significant, are encouraging for physicians and patients. We look forward to presenting the detailed data at an upcoming medical meeting.”
The most common adverse reactions in PALOMA-3 included neutropenia, leukopenia, infections, fatigue and nausea; no new safety signals were identified as part of this final OS analysis.
IBRANCE in combination with endocrine therapy is a standard of care for HR+, HER2- metastatic breast cancer. IBRANCE has been prescribed to more than 120,000 patients globally to date.
The full prescribing information for IBRANCE can be found at www.pfizer.com.
Original source can be found here.