Evaluating ribociclib plus hormonal therapy in breast cancer

This study wanted to find out how well patients with hormone-receptor-positive breast cancer survived when treated with ribociclib (Kisqali) added to endocrine therapy. The study found that patients treated with this treatment combination had longer survival compared to endocrine therapy alone.

Advanced breast cancer can be difficult to treat. Breast cancer that is positive for hormone receptors can be treated with specific medicines, which is called endocrine (hormonal) therapy. Adding other drugs to this may help treatment work better. Ribociclib is a medication used to treat breast cancer. It works by stopping the cancer cells from growing. It is not known if adding ribociclib to endocrine therapy will increase the length of survival of patients with hormone receptor-positive breast cancer.

This study had 672 patients. All the patients had advanced breast cancer. The cancer was positive for hormone receptors and HER2-negative. The patients were randomly split into two groups. The first group had 335 patients. These patients were treated with ribociclib and endocrine therapy. The second group had 337 patients. These patients were treated with endocrine therapy only. The patients were followed for 42 months after treatment.

After 42 months, overall survival was 70.2% in the ribociclib group and 46.0% in the endocrine therapy alone group. Patients treated with ribociclib and endocrine therapy had a 29% higher chance of a better survival compared to endocrine therapy alone.

63.5% of the patients who were treated with ribociclib had low white blood cell levels noted during treatment. 4.5% of the patients treated with endocrine therapy only had low white blood cell levels noted during treatment.

The study concluded that adding ribociclib to endocrine therapy in patients with hormone receptor-positive breast cancer increased overall survival.

This study was funded by Novartis, the manufacturer of ribociclib.