Ribociclib-Fulvestrant Combinational Therapy Can Enhance Optimum Survival

Release Date: 27-Sep-2019

Current Study conducted in Barcelona, Spain suggested that addition of ribociclib to fulvestrant provides a synergistic action and significantly extended Overall Survival (OS) among postmenopausal women with hormone receptor-positive, HER2-negative advanced breast cancer. The results of the study were based on the randomized phase 3 MONALEESA-3 trial presented at European Society for Medical Oncology Congress.

The combination of ribociclib (Kisqali, Novartis), which is a cyclin-dependent kinase (CDK) 4/6 inhibitor and fulvestrant, which is an Estrogen Receptor Inhibitor, provide benefit to women who had not previously received hormonal therapy, as well as those who had developed resistance to endocrine therapy. The efficacy of combination is high as compared to the monotherapy.

According to Dennis J. Slamon, MD, PhD, director of clinical/translational research at UCLA Jonsson Comprehensive Cancer Center and chief of the division of hematology/oncology for UCLA’s department of medicine, “these results put to rest the debate about whether this drug should be used in the first-line setting. Many people argued we should hold it in reserve, give hormonal therapy only and wait until recurrence before adding a CDK 4/6 inhibitor. These data clearly show patients have a survival advantage if you give it up front.”

Many of the previously conducted studies showed that the combinations of CDK 4/6 inhibitors and fulvestrant were effective for patients with hormone receptor-positive breast cancer. It is also effective in progression of disease during prior endocrine therapy. However, no study had evaluated the ribociclib-fulvestrant combination for patients with hormone receptor-positive, HER2-negative advanced breast cancer, and no study had evaluated the combination of a CDK 4/6 inhibitor and fulvestrant for patients with hormone receptor-positive, HER2-negative de novo advanced breast cancer or patients who developed relapse more than 1 year after prior endocrine therapy.

Uniquely, MONALEESA-3 is the only trial with a CDK4/6 inhibitor to include patients with endocrine-sensitive as well as those with endocrine-resistant disease. This is the first time when improved overall survival with a combination of a CDK4/6 inhibitor plus fulvestrant in first line treatment is observed. The results of MONALEESA-7 confirmed that HER2-negative advanced breast cancer derived a significant survival benefit from the addition of ribociclib to endocrine therapy.