FDA grants priority review to Pfizer’s breast cancer drug palbociclib

Palbociclib selectively inhibits cyclin-dependent kinases (CDKs) 4 and 6 to regain cell cycle control and block tumor cell proliferation.

Under the new drug application (NDA), the company is seeking FDA approval of palbociclib, a first-line therapy in combination with letrozole, 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 NDA submission is based on data from a randomized Phase II trial PALOMA-1, comparing palbociclib plus letrozole versus letrozole alone in these patients.

PALOMA-1 is designed to evaluate progression-free survival in post-menopausal women with ER+, HER2- advanced breast cancer receiving palbociclib 125mg once daily for three out of four weeks in repeated cycles, in combination with letrozole versus letrozole alone 2.5mg once daily on a continuous regimen.

Pfizer Oncology president Garry Nicholson said if approved as a first-line therapy in combination with letrozole, palbociclib will be an important new option for the thousands of women in the US who are living with metastatic breast cancer.

"We look forward to continuing to work closely with the FDA through the review process," Nicholson said.

In April 2013, the FDA granted breakthrough therapy designation for palbociclib for the first-line systemic treatment of women with advanced or metastatic ER+, HER2- breast cancer.

Recently, the company has also started a multi-center, open-label expanded access program (EAP) in the US for palbociclib.

Image: Pfizer world headquarters. Photo: courtesy of Jim.henderson.