The US Food and Drug Administration (FDA) has accepted for review a supplemental New Drug Application (sNDA) for Pfizer's first-in-class CDK 4/6 inhibitor, IIbrance (palbociclib). The sNDA supports the conversion of the accelerated approval of Ibrance in combination with letrozole to regular approval and includes data from the phase 3 PALOMA-2 trial, which evaluated Ibrance as initial therapy in combination with letrozole for postmenopausal women with estrogen receptor-positive, human epidermal growth factor receptor 2-negative (ER+, HER2-) metastatic breast cancer. This is the same patient population as the randomized phase 2 PALOMA-1 trial upon which the accelerated approval of Ibrance plus letrozole was granted in February 2015.
The sNDA was granted Priority Review status, which accelerates FDA review time from 10 months to a goal of six months from the day of acceptance of filing. The Prescription Drug User Fee Act (PDUFA) goal date for a decision by the FDA is in April 2017.
“Since its introduction in 2015, more than 45,000 patients have been prescribed Ibrance by more than 9,000 providers in the US,” said Liz Barrett, global president and general manager, Pfizer Oncology. “We are pleased that the PALOMA-2 trial has further demonstrated the significant clinical benefit of Ibrance in the first-line setting, providing additional evidence for its continued use as a standard of care medicine.”
PALOMA-2 is a randomized (2:1), multicenter, double-blind Phase 3 study that evaluated a total of 666 women from 186 global sites in 17 countries. The results of PALOMA-2 were presented at the 52nd American Society of Clinical Oncology (ASCO) Annual Meeting in June and recently published in the November 17, 2016 issue of The New England Journal of Medicine. The study demonstrated that Ibrance in combination with letrozole improved progression-free survival compared to letrozole plus placebo as a first-line treatment for postmenopausal women with ER+, HER2- metastatic breast cancer. The adverse events observed with Ibrance in combination with letrozole in PALOMA-2 were generally consistent with their respective known adverse event profiles.
Ibrance is the first and only FDA approved oral inhibitor of CDKs 4 and 6,2 which are key regulators of the cell cycle that trigger cellular progression. Ibrance is approved in more than 50 countries.
In the US, Ibrance is indicated for the treatment of HR+, HER2- advanced or metastatic breast cancer in combination with letrozole as initial endocrine based therapy in postmenopausal women, or fulvestrant in women with disease progression following endocrine therapy. The indication in combination with letrozole is approved under accelerated approval based on PFS. Continued approval for this indication may be contingent upon verification and description of clinical benefit in a confirmatory trial.