On February 3, 2015 Pfizer reported that the U.S. Food and Drug Administration (FDA) has granted accelerated approval of IBRANCE (palbociclib), in combination with letrozole, for the treatment of postmenopausal women with estrogen receptor-positive, human epidermal growth factor receptor 2-negative (ER+/HER2-) advanced breast cancer as initial endocrine-based therapy for their metastatic disease (Press release Pfizer, FEB 3, 2015, View Source [SID:1234501455]). This indication is approved under accelerated approval based on progression-free survival (PFS). Continued approval for this indication may be contingent upon verification and description of clinical benefit in a confirmatory trial. The confirmatory Phase 3 trial, PALOMA-2, is fully enrolled.

IBRANCE was reviewed and approved under the FDA’s Breakthrough Therapy designation and Priority Review programs.

The IBRANCE new drug application was based on the final results of the Phase 2 PALOMA-1 trial. The most frequently reported adverse event for IBRANCE plus letrozole in PALOMA-1 was neutropenia. For more information on the serious and most common side effects of IBRANCE plus letrozole, please see Important IBRANCE Safety Information at the end of this release.

“I am proud of the clinical program for IBRANCE, which was discovered in Pfizer laboratories, and the innovation we are able to bring forward to the breast cancer community today. The registration trial showed that, compared to letrozole alone for first-line treatment of ER+/HER2- advanced breast cancer, IBRANCE in combination with letrozole almost doubled the time before tumor progression, delaying the need for later-line therapies including other hormonal agents and chemotherapies,” said Ian Read, chairman and CEO, Pfizer. “Today’s FDA approval of IBRANCE marks a pivotal milestone that demonstrates the strength of our science, provides an important medicine to patients in need, and underscores the contributions our Company can make to society.”

IBRANCE (palbociclib) is available to order immediately through select specialty pharmacies.

The PALOMA-1 trial achieved its primary endpoint by demonstrating that IBRANCE in combination with letrozole prolonged PFS compared with letrozole alone in postmenopausal women with ER+/HER2- locally advanced or metastatic breast cancer who had not received previous systemic treatment for their advanced disease. For women treated with the combination of IBRANCE plus letrozole, the median PFS was 20.2 months (95% CI: 13.8, 27.5), a substantial improvement compared to the 10.2 months (95% CI: 5.7, 12.6) of PFS in women who received letrozole alone (HR=0.488 [95% CI: 0.319, 0.748]). Overall response rate in patients with measurable disease as assessed by the investigator was higher in the IBRANCE plus letrozole compared to the letrozole alone arm (55.4% versus 39.4%). PALOMA-1 was conducted in collaboration with the Jonsson Cancer Center’s Revlon/UCLA Women’s Cancer Research Program, led by Dr. Dennis Slamon.

“The approval of IBRANCE demonstrates how the strength of Pfizer’s innovative core and strong partnerships with academia can combine to translate novel science into meaningful new medicines. We now have a first-line treatment option that has demonstrated substantial improvement over letrozole alone for postmenopausal women with ER+/HER2- metastatic breast cancer,” said Dr. Mace Rothenberg, senior vice president of Clinical Development and Medical Affairs and chief medical officer for Pfizer Oncology. “IBRANCE represents an important scientific advance, as well as the first medicine in a new class of anti-cancer agents, CDK 4/6 inhibitors, to be approved by the FDA.”

“Metastatic breast cancer patients represent a community that is in great need of more meaningful advances and options in the treatment of metastatic disease,” said Shirley Mertz, president, Metastatic Breast Cancer Network (MBCN). “The approval of IBRANCE represents a major step forward. We are thankful that this important medicine is now widely available to patients.”