Novartis’ CDK4/6 inhibitor Kisqali has picked up Breakthrough status in the US as an initial endocrine-based treatment in certain patients with breast cancer.

The US Food and Drug Administration has awarded the designation for of pre- or perimenopausal women with hormone-receptor positive, human epidermal growth factor receptor-2 negative (HR+/HER2-) advanced or metastatic breast cancer in combination with tamoxifen or an aromatase inhibitor.

The move follows data from the MONALEESA-7 trial, which Novartis says is the first Phase III trial entirely dedicated to evaluating a CDK4/6 inhibitor in premenopausal women with HR+/HER2- advanced breast cancer.

According to the data, Kisqali (ribociclib) in combination with tamoxifen or an aromatase inhibitor as initial endocrine-based therapy significantly prolonged progression-free survival (PFS) compared to endocrine therapy alone, with results showing 23.8 months versus 13.0 months, respectively.

Premenopausal breast cancer is a more aggressive disease than postmenopausal breast cancer, and it is the leading cause of cancer death in women 20-59 years old.

The FDA’s breakthrough designation is designed to speed up development and review of experimental medicines treating serious or life-threatening conditions, when a substantial improvement over an available therapy on at least one clinically significant endpoint has been demonstrated.

The drug was approved in the US in March last year for use in combination with an aromatase inhibitor as initial endocrine-based therapy for treatment of postmenopausal women with the disease, an indication for which it was also previously awarded Breakthrough status.