AARP Hearing Center
Breast cancer can be particularly deadly in younger, premenopausal women, especially when they are diagnosed with advanced metastatic disease. Now a new study shows that adding a newer drug, Kisqali (ribociclib), to standard hormone therapy dramatically increases their survival rates.
The study, published today in the New England Journal of Medicine, looked at 672 premenopausal and perimenopausal women under the age of 59 who received ribociclib in combination with a form of hormone therapy often used to treat breast cancer. At the end of the 42-month study, 70 percent of women on the combination therapy were alive, compared with 46 percent of those treated with only hormone therapy. Women on ribociclib lived on average around 24 months, almost double the length of time (13 months) for those on a placebo.
While past research has shown that the class of drugs that includes ribociclib has prevented metastatic breast cancer from progressing, this is the first study to show that it clearly improves survival rates. “It represents a new standard of care for younger women with advanced-stage breast cancer, in whom cancer can be very aggressive,” says Charles Shapiro, director for translational breast cancer research and director of cancer survivorship at the Icahn School of Medicine at Mount Sinai in New York City.
Most cases of breast cancer are hormone receptor positive, which means they're fueled by estrogen. Up until recently, the mainstay of treatment for these types of advanced cancers was hormone, or endocrine, therapy, which blocks estrogen production so cancer cells can't grow. But a few years ago, three new drugs — ribociclib (Kisqali), abemaciclib (Verzenio) and palbociclib (Ibrance) — were approved to help treat these types of breast cancers. These medicines, a class of drugs known as CDK4/6 inhibitors, work by blocking two proteins that help cancer cells multiply and spread.
Ribociclib had been shown to successfully treat postmenopausal women with advanced-stage, hormone receptor positive breast cancer when used in combination with hormone therapy. A 2016 study published in the New England Journal of Medicine of 668 postmenopausal women found that it prevented cancer from progressing in over 60 percent of women after 18 months, compared with only 42 percent in a placebo group. As a result, it was first approved by the FDA to treat postmenopausal women with advanced breast cancer in 2017, and then in 2018 for pre/perimenopausal women.