Otsuka Pharmaceutical Co., Ltd. (Otsuka) announces that its U.K.-based subsidiary Astex Pharmaceuticals ("Astex"), a pharmaceutical company dedicated to the discovery and development of novel small molecule therapeutics for oncology and diseases of the central nervous system, today announces that it has entered into an exclusive, worldwide research collaboration and license agreement with Genentech, a member of the Roche Group, to identify small molecule drug candidates with selective inhibitory activity as potential treatments for breast cancer.

Under the terms of the agreement, Astex will grant Genentech an exclusive licence to compounds from Astex's existing drug discovery program for breast cancer and will collaborate with Genentech to accelerate the further optimisation and development of lead compounds towards the identification of preclinical candidates. Genentech will be solely responsible for pre-clinical and clinical development of lead candidates as well as commercialisation of all medicines arising from the collaboration globally. Astex will receive an upfront payment of $25 million and is eligible to receive further payments on the achievement of preclinical, clinical, regulatory and sales milestones, potentially totalling more than $490 million, as well as tiered royalties on net sales of medicines arising from the collaboration.

Astex's drug discovery program originated from an earlier collaborative project under Astex's strategic alliance agreement with the Newcastle University and Cancer Research Horizons.

Michelle Jones, president of Astex Pharmaceuticals, said, "Working together with colleagues from Newcastle University, Astex's fragment-based drug discovery expertise has led to the discovery of a novel and innovative approach to selectively inhibit this key oncology target for breast cancer therapy. Genentech's focus on embracing innovation, its expertise in oncology and its longstanding dedication to innovation for breast cancer patients makes Genentech an excellent partner for this collaboration. We are delighted to be working together in this important drug discovery alliance with the aim to build on our progress and accelerate compounds into development in a rapidly emerging area of need which, as yet, remains unmet."

"We are committed to pushing the boundaries of scientific innovation and turning breakthroughs into better outcomes for people with breast cancer," said Boris L. Zaïtra, Head of Roche Corporate Business Development. "Working alongside partners like Astex Pharmaceuticals in pursuit of precision therapies against cell-cycle regulators, we follow the science to focus our innovation on the areas of the highest unmet need."

About Astex Pharmaceuticals

Astex is a leader in innovative drug discovery and development, committed to the fight against cancer and diseases of the central nervous system. Astex is developing a proprietary pipeline of novel therapies and has a number of partnered products that are approved or are being developed under collaborations with leading pharmaceutical companies. Astex is a wholly owned subsidiary of Otsuka Pharmaceutical Co. Ltd., based in Tokyo, Japan. For more information about Astex Pharmaceuticals please visit: http://www.astx.com

About Otsuka

Otsuka Pharmaceutical Co., Ltd. is a total healthcare company that focuses on each individual's potential to enhance their well-being. Our medical-related business provides treatments and diagnostics for both physical and mental health. Our nutraceutical business supports daily health maintenance and improvement. Otsuka's unique products and services are based on scientific evidence, under the guidance of our corporate philosophy: Otsuka-people creating new products for better health worldwide. For further information, please visit www.otsuka.co.jp/en/