Pfizer Inc. has announced that the company has initiated a multi-center, open-label expanded access program (EAP) in the United States for the investigational CDK 4/6 inhibitor, palbociclib. Through the program, palbociclib is being made available for use in combination with letrozole for post-menopausal women with hormone receptor positive (HR+), human epidermal growth factor receptor 2 negative (HER2-) advanced breast cancer for whom letrozole is considered appropriate therapy. Healthcare professionals and patients can learn more about the palbociclib EAP by visiting www.clinicaltrials.gov (trial number: NCT02142868).

Under its expanded access programs, the U.S. Food and Drug Administration (FDA) works with companies to allow access to investigational therapies to patients with serious or life-threatening illnesses who do not otherwise qualify for participation in a clinical trial and for whom there are no comparable or satisfactory alternate therapies.

"Palbociclib is being evaluated as a potential new treatment for women with HR+, HER2- advanced breast cancer, who represent the largest subgroup of women with this disease," said Dr. Mace Rothenberg, senior vice president, Clinical Development and Medical Affairs, and chief medical officer, Pfizer Oncology. "As announced this week, we have completed the submission of a New Drug Application for palbociclib in the U.S. based on the results of our Phase 2, PALOMA-1 study. With recruitment of new patients to our Phase 3 PALOMA-2 and PALOMA-3 trials now complete, Pfizer is initiating the Palbociclib Expanded Access Program. This program will provide a mechanism by which eligible women who may benefit from treatment with palbociclib can gain access to this investigational therapy at this time."

About the Palbociclib EAP

The palbociclib EAP is a U.S.-only, single-arm, open label study for post-menopausal women with HR+, HER2- advanced breast cancer. Women enrolled to the study will receive palbociclib for use in combination with letrozole, and therefore must be deemed appropriate for letrozole therapy. Additional enrollment criteria are available at www.clinicaltrials.gov (trial number: NCT02142868).

U.S.-based health care professionals seeking more information about the palbociclib EAP can call 1-800-420-6755 or e-mail Palbociclib-EAP@parexel.com for further details.

Patients who are interested in enrolling to the palbociclib EAP should speak with their physician to understand if palbociclib is an appropriate treatment option.

Palbociclib is an investigational therapy and is not approved for any indication in any markets.

About Palbociclib

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. CDK 4/6 are key regulators of the cell cycle that trigger cellular progression from growth phase (G1) into phases associated with DNA replication (S). CDK 4/6, whose increased activity is frequent in estrogen receptor-positive (ER+) breast cancer (BC), are key downstream targets of ER signaling in ER+ BC. Preclinical data suggest that dual inhibition of CDK 4/6 and ER signaling is synergistic and has been shown to stop growth of ER+ BC cell lines in the G1 phase.