GPC Biotech Announces Achievement of Target Enrollment in Satraplatin Phase 3 Registrational Trial (SPARC) for Second-Line Chemotherapy of Hormone Refractory Prostate Cancer

Martinsried/Munich (Germany) and U.S. Research and Development
Facilities in Waltham/Boston, Mass. and Princeton, N.J., December 5,
2005 - GPC Biotech AG (Frankfurt Stock Exchange: GPC; TecDAX index;
NASDAQ: GPCB) today announced the achievement of target enrollment in
the Phase 3 registrational trial of its lead drug candidate
satraplatin, the only orally bioavailable platinum-based compound in
advanced clinical development. More than 200 clinical sites in
fifteen countries on four continents have now achieved the goal of
accruing 912 patients to the SPARC (Satraplatin and Prednisone
Against Refractory Cancer) trial. A number of additional patients are
in screening, and the Company will allow those patients to complete
the process and either be randomized into the trial or disqualified,
in accordance with the trial protocol. The SPARC trial is a
multicenter, multinational, double blind, randomized study that is
assessing the safety and efficacy of satraplatin in combination with
prednisone as a second-line chemotherapy in patients with
hormone-refractory prostate cancer (HRPC).

"We are excited to have achieved this major milestone in the
development of satraplatin. This is indeed a significant
accomplishment for GPC Biotech," said Bernd R. Seizinger, M.D.,
Ph.D., Chief Executive Officer. "The rapid accrual rate of the SPARC
trial supports the need for effective second-line chemotherapy
treatments for hormone-refractory prostate cancer patients. We are
thus committed to completing the study and moving forward in the
registration process as expeditiously as possible."

"The accrual goal of 912 patients was reached in just over 26 months,
making the SPARC trial one of the fastest accrued Phase 3 clinical
trials for chemotherapy drugs in prostate cancer. This rapid
enrollment was made possible by the dedication and hard work of the
clinical investigators, the study site personnel and our own drug
development team," said Marcel Rozencweig, M.D., Senior Vice
President, Drug Development. "I would like to thank them, as well as
all of the patients who participated in the trial."

About Prostate Cancer
Prostate cancer is the most common cancer among men in the U.S. and
Europe. Approximately 232,000 men in the U.S. are expected to be
diagnosed with the disease in 2005. With over 30,000 U.S. deaths
estimated for 2005, prostate cancer is the second leading cause of
cancer-related death in men - second only to lung cancer. In the
European Union, 138,000 new cases are expected to be diagnosed, and
45,000 patients to die within the same time period. Since the
incidence of prostate cancer increases with age, the aging of the
overall population is expected to further increase the number of
prostate cancer patients.

Most patients diagnosed with prostate cancer initially receive
surgery or radiation therapy, and some of these patients are cured.
For many others, though, the disease recurs. At this point, the
recurrent disease is treated with hormone therapy, and most patients
initially respond well to this treatment. Eventually, however, the
tumor cells become resistant to the hormones - or
"hormone-refractory" - and the tumor again progresses. Increasingly,
chemotherapy is being used as an effective first-line treatment for
HRPC. However, it is not a cure, and so this is creating a need for
effective therapeutic options as second-line chemotherapy treatments
for these patients once they have progressed.

About Satraplatin
Satraplatin, an investigational drug, is a member of the platinum
family of compounds. Over the past two decades, platinum-based drugs
have become a critical part of modern chemotherapy treatments and are
used to treat a wide variety of cancers. Worldwide sales of these
drugs exceeded $2.2 billion in 2004. Unlike the platinum drugs
currently on the market, all of which require intravenous
administration, satraplatin is an orally bioavailable compound and is
given as capsules that patients can take at home. An oral platinum
drug could offer key advantages, including ease of administration and
patient convenience, in a variety of applications. Satraplatin is in
a Phase 3 registrational trial - the SPARC trial - as a second-line
chemotherapy treatment for HRPC. GPC Biotech has completed a Special
Protocol Assessment with the U.S. FDA and has received a Scientific
Advice letter from the European regulatory authority, the European
Medicines Agency (EMEA). The FDA has also granted fast track
designation to satraplatin for this indication.

Phase 2 trials have been completed in HRPC, ovarian cancer and small
cell lung cancer. Promising early clinical results have also been
shown when satraplatin is combined with radiation therapy, and a
Phase 1/2 study evaluating this combination in patients with
non-small cell lung cancer has been initiated. Several other studies
evaluating satraplatin in combination with other therapies and in
various cancers are underway or planned. Further information on
satraplatin can be found in the Anticancer Programs section of the
Company's Web site at www.gpc-biotech.com.

GPC Biotech AG is a biopharmaceutical company discovering and
developing new anticancer drugs. The Company's lead product candidate
- satraplatin - is currently in a Phase 3 registrational trial as a
second-line chemotherapy treatment in hormone-refractory prostate
cancer following completion of a Special Protocol Assessment by the
U.S. FDA and receipt of a Scientific Advice letter from the European
central regulatory authority, EMEA. The FDA has also granted fast
track designation to satraplatin for this indication. The Company 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 has a multi-year alliance with ALTANA Pharma AG working
with the ALTANA Research Institute in the U.S., which provides GPC
Biotech with revenues through mid-2007. GPC Biotech AG is
headquartered in Martinsried/Munich (Germany). The Company's wholly
owned U.S. subsidiary has research and development sites in Waltham,
Massachusetts and Princeton, New Jersey. For additional information,
please visit the Company's Web site at www.gpc-biotech.com.


This press release may contain projections or estimates about plans
and objectives relating to our future operations, products, or
services; future financial results; or assumptions underlying or
relating to any such statements. These statements are forward-looking
and are subject to risks and uncertainties, many of which are beyond
our control. Actual results could differ materially depending on a
number of factors, including the timing and effects of regulatory
actions, the results of clinical trials, the Company's relative
success developing and gaining market acceptance for any new
products, and the effectiveness of patent protection. There can be
no guarantee regarding the results of the SPARC trial or other
ongoing studies with satraplatin nor that satraplatin will be
approved for marketing in a timely manner, if at all. We direct you
to the Company's Annual Report on Form 20-F, as amended, for the
fiscal year ended December 31, 2004 and other reports filed with the
U.S. Securities and Exchange Commission for additional details on the
important factors that may affect the Company's future results,
performance and achievements. The Company disclaims any intent or
obligation to update these forward-looking statements or the factors
that may affect the Company's future results, performance or
achievements, 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
Associate Director, Investor Relations & Corporate
Communications
Phone: +49 (0)89 8565-2693
ir@gpc-biotech.com

Additional Media Contacts:
In Europe:
Maitland Noonan Russo
Brian
Hudspith
Phone: +44 (0)20 7379 5151
bhudspith@maitland.co.uk

In the U.S.:
Laurie Doyle
Associate Director, Investor Relations &
Corporate Communications
Phone: +1 781 890 9007 X267
usinvestors@gpc-biotech.com

In the U.S.:
Euro RSCG Life NRP
Matt Haines
Phone: +1 212 845
4235
matthew.haines@eurorscg.com
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