- Medical Updates

Updated median overall survival ( OS ) results for Ribociclib ( Kisqali ) in combination with Fulvestrant ( Faslodex ) in postmenopausal women with hormone receptor positive, human epidermal growth factor receptor-2 negative ( HR+/HER2- ) metastatic breast cancer were announced.

The exploratory analysis of overall survival after an additional 16.9 months of follow-up of the phase III MONALEESA-3 trial has evaluated Ribociclib plus Fulvestrant as first- or second-line treatment compared to Fulvestrant alone in postmenopausal women with HR+/HER2- metastatic breast cancer. The analysis found that with extended follow-up of more than four years, Ribociclib in combination with Fulvestrant continued to demonstrate a clinically relevant overall survival benefit of more than a year compared with Fulvestrant alone.

After a median follow-up of 56.3 months, median overall survival for patients taking Ribociclib in combination with Fulvestrant was 53.7 months versus 41.5 months for Fulvestrant alone ( hazard ratio, HR=0.73; 95% CI: 0.59-0.90 ).
Additionally, Ribociclib plus Fulvestrant had prolonged overall survival in the first-line ( median, not reached vs 51.8 months; HR=0.64; 95% CI: 0.46-0.88 ) and second-line ( median, 39.7 vs 33.7 months; HR=0.78; 95% CI: 0.59-1.04 ) treatment subgroups.

This exploratory ad hoc analysis follows the previously reported MONALEESA-3 overall survival analysis presented at the European Society of Medical Oncology ( ESMO ) Congress 2019 and published in the New England Journal of Medicine, which demonstrated statistically significant overall survival results for Ribociclib in combination with Fulvestrant with a 28% reduction in the risk of death ( HR=0.72; 95% CI: 0.568-0.924; p=0.00455 ).
Results from the subgroup analyses were consistent with the survival data seen with the intent-to-treat ( ITT ) population.

The need for chemotherapy was delayed to 4 years ( 48.1 months ) in patients taking Ribociclib in combination with Fulvestrant and 28.8 months in the patients taking Fulvestrant alone ( HR=0.70; 95% CI: 0.57-0.88 ).

Adverse events were consistent with previously reported phase III trial results.

Kisqali was initially approved by the US Food and Drug Administration ( FDA ) in March 2017 and by the European Commission ( EC ) in August 2017, as initial endocrine-based therapy for postmenopausal women with HR+/HER2- locally advanced or metastatic breast cancer in combination with an aromatase inhibitor based on findings from the pivotal MONALEESA-2 trial.
Kisqali in combination with an aromatase inhibitor was approved for the treatment of pre-, peri- or postmenopausal women as initial endocrine-based therapy, and is also indicated for use in combination with Fulvestrant as both first- or second-line therapy in postmenopausal women by the FDA in July 2018 and by the EC in December 2018. ( Xagena )

Source: Novartis, 2021