FDA Approves Ibrance (Palbociclib) for Breast Cancer

The US Food and Drug Administration (FDA) has approved a new drug for women with a certain type of breast cancer that has metastasized – spread to other parts of the body. Ibrance (palbociclib) is for postmenopausal women who have not already had drug treatment, whose breast cancer is estrogen receptor (ER)-positive and human epidermal growth factor receptor 2 (HER2)-negative. It’s meant to be taken along with another drug, letrozole.

Ibrance works by blocking 2 enzymes involved in helping cancer cells grow. It was approved under the FDA’s accelerated approval program for drugs that show promise against a serious disease.

The approval is based on a study of 165 postmenopausal women with ER-positive, HER2-negative, metastasized breast cancer who had not received any previous treatment. About half the women received Ibrance and letrozole and the other half received letrozole alone. The women who received both Ibrance and letrozole lived about 20 months without their cancer getting worse, compared to about 10 months for the women who received letrozole alone.

Both Ibrance and letrozole are pills taken by mouth once a day.

The most common side effects of Ibrance were infection, low white blood counts, anemia, fatigue, weakness, nausea, mouth sores, hair loss, diarrhea, poor appetite, nerve damage, and nosebleed.

Ibrance is marketed by Pfizer, Inc.

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