Astex Pharmaceuticals Urges Shareholders to Tender Shares into Otsuka Offer

The Board of Directors of Astex Pharmaceuticals

today issued a letter to Astex stockholders addressing recent mischaracterizations of the pending acquisition of the Company by Otsuka Pharmaceutical Co., Ltd.

. The full text of the letter follows: October 2, 2013 Dear Fellow Stockholder, A number of misstatements and falsehoods have recently been circulated regarding the current tender offer from Otsuka to acquire Astex. Our public statements and SEC filings have been consistent as to the thoroughness of the sale process and the resulting merger agreement. The purpose of this letter is to set the record straight. To understand why we, the Astex Board of Directors, have unanimously determined that the Otsuka transaction is in the best interest of Astex stockholders, consider the following: The Otsuka transaction is the culmination of a comprehensive process to maximize value for Astex stockholders. As part of that process, 33 pharmaceutical companies worldwide were contacted to gauge their interest in exploring a potential strategic transaction with Astex. All companies contacted