Exhibit 23.3 CONSENT OF INDEPENDENT ACCOUNTANTS We hereby consent to the incorporation by reference in this Registration Statement on Form S-8 of our report dated December 23, 2003, relating to the financial statements of Ribopharma AG, which appears in the Registration Statement on Form S-1, as amended as of May 27, 2004. PricewaterhouseCoopers June 3, 2004 Gesellschaft mit beschrankter Haftung Wirtschaftsprufungsgesellschaft Munich, Germany /s/ Price /s/ McMahon Price McMahon