Otsuka Pharmaceutical Co., Ltd.

October 19, 2016

Positive Phase III Clinical Trial Results for Ribociclib (LEE011), an Investigational Compound for Advanced Breast Cancer in Development by Major Pharmaceutical Company under a Research Collaboration with Otsuka's Subsidiary Astex Pharmaceuticals

Otsuka Pharmaceutical Co., Ltd., which is active in the discovery of new medicines in the fields of cancer and central nervous system diseases announces positive phase III trials results for a drug compound in development by Novartis related to its subsidiary Astex Pharmaceuticals.

Positive clinical trial results on ribociclib (LEE011) plus letrozole as first-line treatment for advanced or metastatic breast cancer, compared to letrozole alone, were presented by Novartis at the European Society for Medical Oncology (ESMO) 2016. (The contents of this press release were announced earlier by Novartis in an October 8 press release. See the press release on the trial results including full safety and efficacy data here.)

In the trial (MONALEESA-2 study), patients with HR+ (hormone receptor positive)/HER2- (human epidermal growth factor receptor 2-negative), advanced or metastatic breast cancer were assigned to treatment with ribociclib (LEE011) and letrozole or to the standard of care: letrozole alone. Progression-free survival (the length of time during which cancer does not progress) was significantly extended in the experimental group treated with ribociclib plus letrozole. Trial results were published simultaneously in an online article in The New England Journal of Medicine.

Ribociclib (LEE011) was developed by the Novartis Institutes for BioMedical Research under a research collaboration with Astex Pharmaceuticals.
Otsuka's subsidiary Astex undertakes drug discovery in the U.K. directed at unmet medical needs in the field of oncology and diseases of the CNS, thereby contributing to the lives of patients and their families.