Pfizer’s IBRANCE (palbociclib) now approved for use in women with HR+, HER2- metastatic breast cancer

Pfizer Inc. (NYSE:PFE) today announced that the U.S. Food and Drug Administration (FDA) has approved a new indication expanding the use of IBRANCE^® (palbociclib) 125mg capsules, Pfizer’s metastatic breast cancer therapy. Now IBRANCE also is approved for the treatment of hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) advanced or metastatic breast cancer in combination with fulvestrant in women with disease progression following endocrine therapy. Pfizer’s supplemental New Drug Application (sNDA) for IBRANCE was reviewed and approved under the FDA’s Breakthrough Therapy designation and Priority Review programs based on results from the Phase 3 PALOMA-3 trial in pre-, peri- and post-menopausal women with HR+, HER2- metastatic breast cancer whose disease progressed on or after prior endocrine therapy in the adjuvant or metastatic setting.

IBRANCE first was approved in February 2015 and also is indicated for the treatment of HR+, HER2- advanced or metastatic breast cancer in combination with letrozole as initial endocrine-based therapy in postmenopausal women. The indication in combination with letrozole 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 is the first and only cyclin-dependent kinase 4/6 (CDK 4/6) inhibitor approved by the FDA.

“Today's news gives more women with metastatic breast cancer the opportunity to benefit from this first-in-class medicine," said Liz Barrett, global president and general manager, Pfizer Oncology. “Since IBRANCE was approved just over one year ago, physicians across the U.S. have embraced it as a standard of care in the first-line setting. The expanded approval of IBRANCE is supported by a robust body of evidence and underscores Pfizer's continued commitment to addressing the needs of the metastatic breast cancer community. Pfizer is proud to bring forward innovative therapies like IBRANCE that make a meaningful difference in patients' lives.”

The Phase 3 PALOMA-3 trial enrolled 521 women, regardless of menopausal status, randomized 2:1 to receive IBRANCE plus fulvestrant or placebo plus fulvestrant. This trial demonstrated that IBRANCE in combination with fulvestrant, a standard of care hormonal therapy, prolonged PFS compared with placebo plus fulvestrant in women with HR+, HER2- metastatic breast cancer whose disease progressed on or after prior endocrine therapy. Women in the IBRANCE plus fulvestrant arm had a median PFS of 9.5 months (95% CI: 9.2, 11.0), a substantial improvement compared with 4.6 months (95% CI: 3.5, 5.6) in the group treated with placebo plus fulvestrant [HR 0.461 (95% CI: 0.360, 0.591), p <0.0001]. Confirmed overall response rate in patients with measurable disease as assessed by the investigator was 24.6% for the IBRANCE plus fulvestrant arm compared to 10.9% for the placebo plus fulvestrant arm. Duration of response was 9.3 months in the IBRANCE plus fulvestrant arm compared with 7.6 months in the placebo plus fulvestrant arm.

The warnings and precautions of IBRANCE include neutropenia, pulmonary embolism and embryo-fetal toxicity. The most common adverse reactions (≥10%) of any grade reported in PALOMA-3 of IBRANCE plus fulvestrant vs fulvestrant plus placebo included neutropenia (83% vs 4%), leukopenia (53% vs 5%), infections (47% vs 31%), fatigue (41% vs 29%), nausea (34% vs 28%), anemia (30% vs 13%), stomatitis (28% vs 13%), headache (26% vs 20%), diarrhea (24% vs 19%), thrombocytopenia (23% vs 0%), constipation (20% vs 16%), vomiting (19% vs 15%), alopecia (18% vs 6%), rash (17% vs 6%), decreased appetite (16% vs 8%), and pyrexia (13% vs 5%). For more information, please see Important Safety Information for IBRANCE below.

“There currently is no cure for metastatic breast cancer, so ongoing treatment is usually needed to control the spread of the disease,” said Marisa Weiss, M.D., chief medical officer and founder, Breastcancer.org. “That's why the availability of a first-of-its-kind treatment option like IBRANCE for women dealing with HR+, HER2- metastatic disease represents a very important advance.”

Both palbociclib (IBRANCE) combination options are recommended by the National Comprehensive Cancer Network. Palbociclib plus letrozole is recommended (category 2A) as a first-line treatment for postmenopausal women with HR+, HER2- metastatic breast cancer. Palbociclib plus fulvestrant is recommended (category 1) for postmenopausal women with HR+, HER2- metastatic breast cancer who have progressed on endocrine therapy or premenopausal women receiving a luteinizing hormone-releasing hormone (LHRH) agonist.