The designation aims to expedite the development and review of potential new medicines that treat severe or life-threatening conditions.
It came after positive data from the Phase III MONALEESA-2 trial, involving postmenopausal women who had received no prior therapy for their advanced disease, demonstrating an improvement in progression free survival in those taking the drug.
The trial is continuing to evaluate overall survival data. Full results of the study are to be presented at an upcoming medical congress and it will form the basis of regulatory discussions in the US, Europe and other countries for use in this indication.
Novartis Oncology global head of oncology development and medical affairs Alessandro Riva said: "Despite advancements in treatment, an estimated 40,000 individuals in the United States die each year from advanced breast cancer.
"This designation shows the potential of LEE011, and we look forward to close collaboration with the FDA and the advanced breast cancer community to provide a new treatment option for women living with HR+/HER2- advanced breast cancer as quickly as possible."
LEE011, which has been studied in non-clinical models, is currently being assessed in combination with additional endocrine agents as part of the MONALEESA clinical trial program.
The drug is currently not approved for any indication in any market.
Image: Novartis headquarters in Basel. Photo: courtesy of –Andrew- from Flickr.