GPC Biotech Announces Initiation of NCI-Sponsored Phase 2 Trial of Satraplatin in Patients With Metastatic Hormone-Refractory Prostate Cancer Previously Treated With Docetaxel

Study seeks to determine if presence of certain gene impacts patient outcome

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GPC Biotech AG (Frankfurt Stock Exchange: GPC, NASDAQ: GPCB) today announced the initiation of a Phase 2 study evaluating satraplatin in combination with the steroid, prednisone, in patients with metastatic hormone-refractory prostate cancer (HRPC) who previously have been treated with docetaxel (Taxotere(R)). The study is being sponsored by the U.S. National Cancer Institute (NCI), and the principal investigator is William L. Dahut, MD, Chief, Genitourinary Research Section, Medical Oncology Branch, Center for Cancer Research, NCI.

The trial is a single-arm study with a planned enrollment of 66 patients with metastatic HRPC who have been previously treated with docetaxel therapy and with no more than one other previous cytotoxic chemotherapy regimen. The primary objective of the trial is to determine if the presence of certain variants of the gene, ERCC1, affects progression-free survival in this patient population. ERCC1 is involved in DNA damage repair. Satraplatin, like other platinum agents, has been shown to work via targeting the DNA in tumor cells.

“The results of this trial may provide important information in determining which hormone-refractory prostate cancer patients are more likely to benefit from treatment with satraplatin,” said Martine George, MD, Senior Vice President, Drug Development and Chief Medical Officer at GPC Biotech. “We are pleased to be working with the NCI to conduct this potentially ground-breaking study.”

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. A Marketing Authorization Application for satraplatin in combination with prednisone is currently under review in Europe for the treatment of hormone-refractory prostate cancer patients whose prior chemotherapy has failed. A decision on the filing by the European regulators is expected in the second half of 2008.

About GPC Biotech

GPC Biotech AG is a publicly traded biopharmaceutical company focused on 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 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, including statements about the efficacy and safety 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. Satraplatin may not be approved for marketing in a timely manner, if at all. 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.

Satraplatin has not been approved by the FDA in the U.S., the EMEA in Europe or any other regulatory authority and no conclusions can or should be drawn regarding its safety or effectiveness. Only the relevant regulatory authorities can determine whether satraplatin is safe and effective for the use(s) being investigated.

Taxotere(R) is a registered trademark of Aventis Pharma S.A.

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