"Three anticancer therapeutics that target cell-cycle mediators CDK4 and CDK6, so-called CDK4/6 inhibitors, have been approved by the FDA for use in combination with hormonal drugs, either aromatase inhibitors or fulvestrant, for treating postmenopausal women with HR-positive, HER2-negative advanced breast cancer", said Debu Tripathy, MD, Professor of Medicine and Chair of the Department of Breast Medical Oncology at The University of Texas MD Anderson Cancer Center in Houston.
The MONALEESA-7 trial met its primary endpoint of progression-free survival in premenopausal women with hormone-receptor positive, human epidermal growth factor receptor-2 negative advanced breast cancer. A total of 672 patients with HR+, HER2- ABC were randomized in a 1:1 ratio to ribociclib or placebo combined with tamoxifen or letrozole/anastrozole + goserelin. The overall response rate was 51 percent for ribociclib versus 36 percent for placebo, and clinical benefit rate was 80 versus 67 percent in patients with measurable disease at baseline. All tumours in the study cohort were centrally assessed for HER2 positivity, PD-1 ligand (PD-L1) status, and quantity of tumour-infiltrating lymphocytes (TILs). Other adverse events included hot flashes, nausea, leukopenia, and joint pain/stiffness. Results of MONALEESA-7 trial will be presented at the 40th annual San Antonio Breast Cancer Symposium in December.
"Longer follow-up is needed to determine whether the trial will meet its secondary end point of overall survival", Tripathy said in a statement.