US-based pharmaceutical company Pfizer has submitted a new drug application (NDA) for palbociclib to the US Food and Drug Administration (FDA).

Palbociclib is an investigational oral targeted agent, which selectively inhibits cyclin-dependent kinases (CDKs) four and six to regain cell cycle control and block tumour cell proliferation.

The company is seeking approval for palbociclib, in combination with letrozole, to treat post-menopausal women with estrogen receptor positive (ER+) and human epidermal growth factor receptor two negative (HER2-) advanced breast cancer.

"Today’s submission marks an important milestone for Pfizer and palbociclib."

Pfizer Oncology president Garry Nicholson said: "Today’s submission marks an important milestone for Pfizer and palbociclib, and a potential advance for women with advanced breast cancer."

Pfizer has submitted the application based on the final results of PALOMA-1, a randomised, phase II trial comparing palbociclib plus letrozole with just letrozole.

PALOMA-1 was designed to assess progression-free survival in post-menopausal women with ER+, HER2- advanced breast cancer who were receiving palbociclib in combination with letrozole rather than just letrozole.

The company has presented the PALOMA-1 final results at the American Association for Cancer Research (AACR) Annual Meeting 2014.

In addition, the company has started two phase III studies of palbociclib in advanced / metastatic breast cancer.

In April 2013, Palbociclib received Breakthrough Therapy designation from the FDA to treat women with advanced or metastatic ER+, HER2- breast cancer.

Pfizer noted that palbociclib is not approved for any indication in any market.