GPC Biotech Announces Favorable Ruling in Arbitration with Spectrum Pharmaceuticals

* Arbitration panel unanimously rejects all of Spectrum's claims and finds no violations of contract by GPC Biotech Martinsried/Munich (Germany) and Princeton, N.J., November 5, 2007 - GPC Biotech AG (Frankfurt Stock Exchange: GPC; TecDAX index; NASDAQ: GPCB) today announced that a three-arbitrator panel of the American Arbitration Association, which was appointed to resolve a dispute over claims raised by Spectrum Pharmaceuticals, Inc. against GPC Biotech regarding their co-development and license agreement for satraplatin, has issued its decision in favor of GPC Biotech. The panel unanimously rejected all of Spectrum's claims and found no violations of the agreement by GPC Biotech. The decision of the panel included the following key rulings: * Spectrum Pharmaceuticals is not entitled to any portion of the up-front payments that GPC Biotech received from Pharmion Corporation or from Yakult Honsha Co. Ltd.; * Spectrum does not have a contractual right to co-promote satraplatin in the United States and GPC Biotech did not violate any obligation to negotiate in good faith a co-promotion agreement; and * GPC Biotech did not violate its obligation to use commercially reasonable efforts to commercialize satraplatin in Japan. Bernd R. Seizinger, M.D., Ph.D., Chief Executive Officer, said: "GPC Biotech takes its contractual obligations to its partners very seriously. We are pleased that the panel unanimously agreed that all of Spectrum's allegations were without merit and that we committed no violations of the agreement." Although the panel ruled for GPC Biotech on the merits, it did not award GPC Biotech re-imbursement of attorneys' fees and costs. Background on Arbitration In December 2006, GPC Biotech was notified by Spectrum Pharmaceuticals that Spectrum had initiated an arbitration proceeding with the American Arbitration Association in the United States to resolve a dispute between the companies under the co-development and license agreement for satraplatin. In the course of the arbitration proceedings, Spectrum made several claims of breach of contract, including (1) an assertion that it is entitled to a payment from GPC Biotech of approximately ¤ 9.0 million relating to payments received by GPC Biotech under the co-development and license agreement between GPC Biotech and Pharmion GmbH entered on December 19, 2005, later expanded to also include a claim to a portion of the payments GPC Biotech was entitled to from Yakult Honsha Co. Ltd. under their license agreement for Japan; (2) a claim that GPC Biotech had not used commercially reasonable efforts to obtain regulatory approval and to promote the distribution of satraplatin in Japan; and (3) a claim that GPC Biotech had not negotiated with Spectrum in good faith regarding the co-promotion of satraplatin in the United States. Spectrum was also seeking a declaration that GPC Biotech's alleged breaches of contract provided a basis for termination of the co-development and license agreement. The hearing was completed on July 13, 2007 and closing arguments were heard on August 21, 2007. 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 is satraplatin, an oral platinum compound. The Company has various anti-cancer programs in research and development 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. 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 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 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, Freiverkehr in Bayerische Börse München, Freiverkehr in Börse Düsseldorf, Freiverkehr in Börse Stuttgart, Freiverkehr in Hanseatische Wertpapierbörse zu Hamburg, Geregelter Markt in Frankfurter Wertpapierbörse;