GPC Biotech Announces Partnering Agreement for Satraplatin for Japan with Yakult

* Deal includes $10 million upfront payment * Yakult responsible for all development, marketing and sales costs for Japan Martinsried/Munich (Germany) and Princeton, N.J., June 25, 2007 - GPC Biotech AG (Frankfurt Stock Exchange: GPC; TecDAX index; NASDAQ: GPCB) today announced that the Company has entered into a license agreement with Yakult Honsha Co. Ltd. for satraplatin in Japan. Under the terms of the agreement, Yakult gains exclusive commercialization rights to satraplatin for Japan and will take the lead in developing the drug in Japan. Yakult is to provide an upfront payment of ¥1.2 billion (~$10 million) to GPC Biotech as reimbursement for past satraplatin clinical development expenses. Yakult will also make GPC Biotech additional payments based on the achievement of certain regulatory filing and approval milestones. GPC Biotech will also receive a minimum of 21% royalties on sales of satraplatin in Japan. Bernd R. Seizinger, M.D., Ph.D., Chief Executive Officer of GPC Biotech, said: "We are delighted to have Yakult as our partner for Japan. Yakult's pharmaceutical business specializes in cancer and cancer-related ailments and has expanded its operations in this area. They are the inventor of irinotecan, which is a global standard drug for colorectal cancer, and have a solid track record of successfully commercializing another platinum-based drug, oxaliplatin, in Japan. They also share the development philosophy of GPC Biotech and plan to develop satraplatin for additional cancer indications for Japan. We look forward to a productive working relationship with Yakult." Teruo Yokokura, Ph.D., Head of Pharmaceutical Division of Yakult Honsha Co., Ltd., said: "We are excited to have the opportunity to develop and commercialize satraplatin for the Japanese market. We look forward to building on the solid foundation of the Phase 3 data from the satraplatin SPARC trial conducted by GPC Biotech in second-line hormone-refractory prostate cancer to bring this product through development, the regulatory process and onto the market in Japan. We believe that, if shown to be effective and well-tolerated, satraplatin, which is given as capsules that patients can take at home, could be an important option for cancer patients in Japan." About Satraplatin Satraplatin, an investigational drug, is a member of the platinum family of compounds. Platinum-based drugs are a critical part of modern chemotherapy treatments and are used to treat a wide variety of cancers. All platinum drugs currently on the market require intravenous administration. Satraplatin is an oral compound that clinical trial patients are able to take at home. Satraplatin is not currently approved by the FDA in the United States, by the EMEA in the European Union or any other regulatory authority and no conclusions can or should be drawn regarding its safety and efficacy. A Phase 3 registrational trial, called SPARC, is evaluating satraplatin plus prednisone versus placebo plus prednisone in 950 patients with hormone-refractory prostate cancer whose prior chemotherapy has failed. Data from the trial showing a statistically significant improvement in progression-free survival and data on prostate specific antigen (PSA) have been presented at recent medical conferences. The satraplatin NDA, filed on February 15 2007, is currently under review by the U.S. FDA for hormone-refractory prostate cancer patients whose prior chemotherapy has failed and will be reviewed by the Oncologic Drugs Advisory Committee (ODAC) on July 24, 2007. The FDA has accepted for filing the Company's NDA and granted the NDA priority review status. An action from the FDA on the application is expected in August of this year. GPC Biotech has a co-development and license agreement with Pharmion GmbH, a wholly owned subsidiary of Pharmion Corporation, under which Pharmion has been granted exclusive commercialization rights to satraplatin for Europe and certain other territories. Pharmion has indicated it expects to complete the Marketing Authorization Application (MAA) for satraplatin for Europe in the second quarter of 2007. GPC Biotech in-licensed satraplatin from Spectrum Pharmaceuticals, Inc. in 2002. Satraplatin has been studied in clinical trials involving a range of tumors. Trials evaluating the effects of satraplatin in combination with radiation therapy, in combination with other cancer therapies and in a number of cancer types are underway or planned. About GPC Biotech GPC Biotech AG is a publicly traded biopharmaceutical company focused on discovering, developing and commercializing new anticancer drugs. GPC Biotech's lead product candidate satraplatin is currently under review by the U.S. FDA for hormone-refractory prostate cancer patients whose prior chemotherapy has failed. GPC Biotech is also developing a monoclonal antibody with a novel mechanism-of-action against a variety of lymphoid tumors, currently in Phase 1 clinical development, and has ongoing drug development and discovery programs that leverage its expertise in kinase inhibitors. GPC Biotech AG is headquartered in Martinsried/Munich (Germany), and has a wholly owned U.S. subsidiary headquartered in Princeton, New Jersey. For additional information, please visit GPC Biotech's Web site at www.gpc-biotech.com. This press release contains forward-looking statements, which express the current beliefs and expectations of the management of GPC Biotech AG, including statements relating to results of the SPARC trial and statements relating to the potential efficacy and safety profile of satraplatin. Such statements are based on current expectations and are subject to risks and uncertainties, many of which are beyond our control, that could cause future results, performance or achievements to differ significantly from the results, performance or achievements expressed or implied by such forward-looking statements. Actual results could differ materially depending on a number of factors, and we caution investors not to place undue reliance on the forward-looking statements contained in this press release. In particular, there can be no guarantee that additional information relating to the safety, efficacy or tolerability of satraplatin may be discovered upon further analysis of data from the SPARC trial or analysis of additional data from other ongoing clinical trials for satraplatin. Furthermore, we cannot guarantee that satraplatin will be approved for marketing in a timely manner, if at all, by regulatory authorities nor that, if marketed, satraplatin will be a successful commercial product. We direct you to GPC Biotech's Annual Report on Form 20-F for the fiscal year ended December 31, 2006 and other reports filed with the U.S. Securities and Exchange Commission for additional details on the important factors that may affect the future results, performance and achievements of GPC Biotech. Forward-looking statements speak only as of the date on which they are made and GPC Biotech undertakes no obligation to update these forward-looking statements, even if new information becomes available in the future. For further information, please contact: GPC Biotech AG Fraunhoferstr. 20 82152 Martinsried/Munich, Germany Martin Braendle Director, Investor Relations & Corporate Communications Phone: +49 (0)89 8565-2693 ir@gpc-biotech.com In the U.S.: Laurie Doyle Director, Investor Relations & Corporate Communications Phone: +1 609 524 5884 usinvestors@gpc-biotech.com Additional Media Contacts: In Europe: Maitland Brian Hudspith Phone: +44 (0)20 7379 5151 bhudspith@maitland.co.uk In the U.S.: Russo Partners, LLC David Schull Phone: +1 212 845 4271 david.schull@russopartnersllc.com --- End of Message --- GPC Biotech AG Fraunhoferstr. 20 Martinsried WKN: 585150; ISIN: DE0005851505; Index: CDAX, MIDCAP, Prime All Share, TecDAX, HDAX, TECH All Share; Listed: Prime Standard in Frankfurter Wertpapierbörse, Freiverkehr in Börse Berlin Bremen, Freiverkehr in Bayerische Börse München, Freiverkehr in Börse Düsseldorf, Freiverkehr in Börse Stuttgart, Freiverkehr in Hanseatische Wertpapierbörse zu Hamburg, Geregelter Markt in Frankfurter Wertpapierbörse;