FDA Approves Breast Cancer Treatment for Postmenopausal Women

The FDA today granted accelerated approval to a drug that treats breast cancer in postmenopausal women by attacking molecules that promote cancer cell growth.

Palbociclib (Ibrance) acts by inhibiting cyclin-dependent kinases (CDKs) 4 and 6, which play a role in promoting the growth of cancer cells. The drug is intended for postmenopausal women who have estrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer but have not yet received an endocrine-based therapy.

Palbociclib is used in combination with letrozole, which treats certain types of breast cancer in postmenopausal women.

“The addition of palbociclib to letrozole provides a novel treatment option to women diagnosed with metastatic breast cancer,” said Richard Pazdur, MD, director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research, in a press release. “The FDA is committed to expediting marketing approval of cancer drugs through our accelerated approval regulations.”

In a clinical trial, palbociclib was evaluated in 165 postmenopausal women with ER-positive, HER2-negative advanced breast cancer who did not receive prior treatment for advanced disease. The participants were randomly assigned to receive palbociclib in combination with letrozole or letrozole alone.

Patients in the palbociclib plus letrozole group experienced approximately 20.2 of progression-free survival, compared with approximately 10.2 months in the group who received letrozole alone. Overall survival data was not immediately available.

Common adverse events associated with palbociclib included neutropenia, leukopenia, fatigue, low red anemia, upper respiratory infection, nausea, stomatitis, alopecia, diarrhea, thrombocytopenia, loss of appetite, vomiting, asthenia, peripheral neuropathy, and nosebleeds.