Novartis' experimental selective cyclin dependent kinase inhibitor LEE011 (ribociclib) is now under review on both sides of the Atlantic as a potential treatment for breast cancer.

Both EU and US regulators are considering the drug's use as first-line treatment of postmenopausal women with hormone-receptor positive, human epidermal growth factor receptor-2 negative (HR+/HER2-) advanced or metastatic breast cancer in combination with letrozole.

The filings are based on a comprehensive clinical package, says Novartis, which includes data from the Phase III MONALEESA-2 trial, showing that ribociclib plus letrozole cut the risk of progression or death by 44 percent over the latter drug alone.

In the US the drug, a selective cyclin dependent kinase inhibitor, has been granted a priority review, potentially leading to faster access for patients.

"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, chief executive of 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."

Despite available therapies, around 40,000 people are dying every year in the US from advanced breast cancer.