Updated data from Phase 3 trial of Ibrance (palbociclib) plus letrozole in ER+, HER2- metastatic breast cancer confirm improvement in progression-free survival.
Pfizer Inc. today announced updated progression-free survival (PFS) results from the Phase 3 PALOMA-2 trial reinforcing the clinical benefit of Ibrance (palbociclib) combined with letrozole.
The data, which will be presented at the 2017 San Antonio Breast Cancer Symposium (SABCS) on December 8 [abstract #P5-21-03], demonstrate that the combination of Ibrance plus letrozole reduced the risk of disease progression by 44 percent and improved median PFS by more than one year compared to letrozole plus placebo (27.6 months [95 percent CI: 22.4, 30.3] vs 14.5 months [95 percent CI: 12.3, 17.1]) when used as the initial treatment for postmenopausal women with estrogen receptor-positive, human epidermal growth factor receptor 2-negative (ER+, HER2-) metastatic breast cancer (HR=0.56 [95percent CI: 0.46, 0.69]).
This updated, post-hoc analysis included a median follow-up of more than three years, which is the longest to date of any Phase 3 study of a CDK 4/6 inhibitor.
The updated data are consistent with results from the primary analysis for PALOMA-2, which showed a median PFS for women treated with Ibrance plus letrozole of 24.8 months (95 percent CI: 22.1, NE) compared with 14.5 months (95 percent CI: 12.9, 17.1) for women treated with letrozole plus placebo (HR=0.58 [95 percent CI: 0.46,0.72], p<0.0001).
Consistent with findings from the primary analysis, the updated data demonstrate that clinical benefit was observed across all patient subgroups receiving the combination of Ibrance and letrozole. Overall survival data were not yet mature at the time of this updated PFS analysis.
“There currently is no cure for metastatic breast cancer, so prolonging progression-free survival and delaying the need for additional anticancer therapies are critical factors in treating these patients,” said Hope Rugo, M.D., lead author and professor of medicine and director of Breast Oncology and Clinical Trials Education at the University of California San Francisco Helen Diller Family Comprehensive Cancer Center. “The updated findings from PALOMA-2 provide additional evidence to support the use of palbociclib with an aromatase inhibitor as a standard of care in the first-line setting for postmenopausal patients with hormone receptor-positive (HR+), HER2- metastatic breast cancer across all patient subgroups.”
At SABCS, 10 additional Pfizer-sponsored abstracts will be presented evaluating Ibrance, several of which explore further analysis of PALOMA-2 along with three real-world studies of patients treated with Ibrance in clinical practice. These real-world data include patients who have received Ibrance in combination with endocrine therapy in various settings and across age groups, including young women (aged 50 years and under, which functioned as a surrogate for premenopausal status in the analysis).
Ibrance was the first CDK 4/6 inhibitor approved by any regulatory authority, and now is approved in more than 75 countries. To date, Ibrance has been prescribed to more than 90,000 patients worldwide.
(Source: Pfizer, Inc.)
Filed Under: Drug Discovery