Pfizer Inc. reports that its new drug application (NDA) for palbociclib has been accepted for filing and granted priority review by the US Food and Drug Administration (FDA). The NDA requests FDA approval of palbociclib, in combination with letrozole, as a first-line treatment for postmenopausal women with estrogen receptor positive (ER+), human epidermal growth factor receptor 2 negative (HER2-) advanced breast cancer who have not received previous systemic treatment for their advanced disease. The submission is based on the final results of a Phase II trial comparing palbociclib plus letrozole versus letrozole alone in this population of patients.

The FDA's priority review status accelerates the review time from 10 months to a goal of six months from the day of acceptance of filing and is given to drugs that may offer major advances in treatment or may provide a treatment where no adequate therapy exists. The Prescription Drug User Fee Act goal date for a decision by the FDA is April 13, 2015.

Palbociclib received breakthrough therapy designation from the FDA in April 2013 for the first-line systemic treatment of women with advanced or metastatic ER+, HER2- breast cancer.

Palbociclib is an investigational oral targeted agent that selectively inhibits cyclin-dependent kinases (CDKs) 4 and 6 to regain cell cycle control and block tumor cell proliferation. Loss of cell cycle control is a hallmark of cancer and CDK 4/6 are overactivated in numerous cancers, leading to loss of proliferative control.

Source: Pfizer