GPC Biotech Opens Enrollment in Phase 1 Trial Evaluating RGB-286638 Multi-Targeted Protein Kinase Inhibitor in Patients with Advanced Solid Tumors

GPC Biotech AG (Frankfurt Stock Exchange: GPC; NASDAQ: GPCB) today announced that enrollment has opened in a Phase 1 study evaluating RGB-286638 in patients with advanced solid tumors. This is the first time that this novel drug candidate is being studied in human clinical trials.

The Phase 1 trial is an open label study being conducted at Erasmus University Medical Center, Rotterdam, The Netherlands under the direction of M.J.A. de Jonge, M.D., Ph.D. The objectives of this study are to evaluate the safety and tolerability and to determine the maximum tolerated dose and recommended Phase 2 dose and schedule for RGB-286638 in patients with advanced solid tumors. The trial is expected to enroll up to approximately 48 patients.

Dr. de Jonge said: “We are pleased to have the opportunity to be the first site to test RGB-286638 in the clinic. Patients in the advanced stages of cancer are in urgent need of new treatments. The pre-clinical profile of RGB-286638 is compelling and justifies clinical testing.”

“We are excited to move RGB-286638 into clinical development,” said Martine George, M.D., Senior Vice President, Drug Development and Chief Medical Officer of GPC Biotech. “Dr. de Jonge and her colleagues at Erasmus University are highly respected for their excellent work in cancer research, and we are pleased to have the opportunity to work with them.”

About RGB-286638

RGB-286638 is a multi-targeted protein kinase inhibitor entering Phase 1 clinical testing. The RGB-286638 compound has been shown in cancer cells to lead to the inhibition of cell cycle progression, the process that controls cell division and ensures the accurate duplication of genetic material, by targeting all relevant cyclin-dependent kinases, which are proteins involved in regulating the cell cycle. RGB-286638 has also been shown to induce apoptosis (programmed cell death) and to inhibit other major protein kinases that are important for the proliferation of cancer cells. In a range of pre-clinical models of solid and hematological tumors, RGB-286638 treatment results in tumor regression and increased survival.

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. 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. There can be no guarantee that RGB-286638 will be successfully developed. We direct you to GPC Biotech’s Annual Report on Form 20-F for the fiscal year ended December 31, 2007 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.