Ribociclib Offers Improved Overall Survival in Postmenopausal Patients with HR-Positive, HER2-Negative Advanced Breast Cancer

New data from Novartis demonstrate that ribociclib (Kisqali) in combination with fulvestrant offers improved median overall survival (OS) in patients with postmenopausal hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer.

In a follow-up of the MONALEESA-3 trial, researchers found that ribociclib plus fulvestrant achieved a median OS of 67.6 months in the first line setting for postmenopausal women with HR-positive HER2- negative advanced breast cancer. When used in the first line, the combination added nearly 16 months of survival benefit to these patients compared to fulvestrant alone, with a 33% relative reduction in the risk of death.

“MONALEESA-3 results continue to demonstrate the survival benefit of treatment with ribociclib for postmenopausal women with advanced breast cancer,” said Dennis J. Slamon, MD, director of clinical/translational research at the University of California, Los Angeles Jonsson Comprehensive Cancer Center, in a press release. “Whether partnered with fulvestrant or an aromatase inhibitor in the first-line setting, ribociclib offers oncologists a CDK4/6 inhibitor with consistent benefit in providing women with HR-positive/HER2-negative advanced breast cancer more quality time, regardless of their disease characteristics.”

Ribociclib is the only cyclin-dependent kinase (CDK) 4/6 inhibitor and fulvestrant combination to demonstrate an OS benefit in this first line setting, according to the study. It remains the CDK 4/6 inhibitor with the longest median OS reported and with consistent benefit seen across 3 phase 3 trials, regardless of combination partner, line of therapy, menopausal status, or site and number of metastases.

In the MONALEESA-3 exploratory analysis, patients were further evaluated for a median of 71 months, more than 2.5 years of additional follow-up since the final key secondary endpoint OS analysis. The final analysis demonstrated a statistically significant OS benefit for ribociclib in combination with fulvestrant and a relative reduction in the risk of death by 28% compared to fulvestrant alone in the full population.

The new updated analysis has a median follow-up of 5 years and found that in the first-line setting, ribociclib plus fulvestrant achieved 67.6 months median OS as compared to 51.8 months for those treated with fulvestrant alone. Patients treated with ribociclib plus fulvestrant compared to those on fulvestrant alone in the first-line setting experienced more than 18 months of additional delay to subsequent use of chemotherapy.

With this extended follow-up, the estimated survival rate at 5 years was 56.5% for women who received ribociclib and fulvestrant in the first-line setting compared to 42.1% for women who received fulvestrant alone. Furthermore, 16.5% of patients in the ribociclib plus fulvestrant arm were still ongoing on therapy at the longer follow-up, compared to 8.6% of those in the fulvestrant only treatment arm.

“The unique profile of Kisquali continues to be reinforced, with results from MONALEESA-3 pushing the boundaries of how using a Kisqali-combination treatment regimen can extend lives of postmenopausal women living with HR-positive/HER2-negative advanced breast cancer without compromising quality of life,” said Jeff Legos, executive vice president and global head of oncology and hematology development at Novartis, in the press release.

REFERENCE

New Novartis data demonstrate only Kisquali offers more life in the first-line setting for postmenopausal HR+/HER2- advanced breast cancer patients. News release. Novartis; May 4, 2022. Accessed May 16, 2022. https://www.novartis.com/news/media-releases/new-novartis-data-demonstrate-only-kisqali-offers-more-life-first-line-setting-postmenopausal-hrher2-advanced-breast-cancer-patients