Novel Breast Cancer Drug Granted Priority Review

The FDA recently granted LEE011 (ribociclib) Priority Review for the treatment of advanced breast cancer, which currently does not have a cure.

LEE011 is a selective cyclin dependent kinase inhibitor, which slows cancer progression by inhibiting cyclin dependent kinase 4 and 6. Increased expression of these proteins can enable cancer proliferation, and targeting these proteins could potentially prevent cancer cell growth and spread.

The FDA will review the New Drug Application filing for the treatment of postmenopausal patients with hormone-receptor positive, human epidermal growth factor receptor-2 negative (HR+/HER2-) advanced or metastatic breast cancer due to positive results from the MONALEESA-2 trial.

The MONALEESA clinical trial program includes MONALEESA-2, MONALEESA-3, and MONALEESA-7, which all explore the use of LEE011 in endocrine therapy combinations in multiple populations, including men and premenopausal women, according to a press release from Novartis.

In MONALEESA-2, 668 treatment-naïve patients were randomized 1:1 to receive LEE011 600 mg/daily, or placebo, in combination with the chemotherapy letrozole 2.5 mg/daily.

This phase 3 clinical trial demonstrated that LEE011 plus letrozole was able to reduce the risk of progression or death by 44% (HR = 0.556, 95% CI: 0.429-0.720; P = 0.00000329) compared with letrozole monotherapy, according to Novartis. All patients taking LEE011 plus letrozole had a significant extension in progression-free survival, which was the primary endpoint of the clinical trial.

Secondary endpoints for this trial included overall survival, overall response rate, clinical benefit rate, health-related quality of life, safety, and tolerability. The European Medicines Agency has also accepted the marketing authorization application for the drug plus letrozole in these patients.

Being granted Priority Review designation means that the FDA is required to take action within a 6-month period rather than the standard 10 months. The drug is currently not approved in any market, and is still being studied in the MONALEESA clinical trial program.

"These regulatory milestones, along with the FDA Breakthrough Therapy designation granted in August, underscore the need for new treatment options for women living with HR+/HER2- advanced breast cancer," said Bruno Strigini, CEO, Novartis Oncology. "Priority Review allows a shorter review period compared with FDA standard review in the US, helping us to potentially bring LEE011 plus letrozole to patients more quickly. We also are working diligently with the EMA and other Health Authorities to bring this treatment to patients around the world as fast as possible."