Press Release April 28, 2003

4SC and ProQinase collaborate on the discovery of new protein kinase inhibitors for cancer treatment

Martinsried and Freiburg, Germany, April 28, 2003
4SC AG and ProQinase GmbH announced today a research collaboration to identify a new generation of protein kinase inhibitors as the basis for the development of new anticancer drugs. Protein kinases are key components of the signaling pathways of cells, including those pathways implicated in the development of tumors.

“ProQinase’s expertise in protein kinase research will provide an excellent starting point for the discovery process,” stated Dr. Ulrich Dauer, CEO of 4SC. “Because of these existing validated targets, we believe that this collaboration will quickly advance potential drug candidates through research into clinical trials.”

ProQinase will provide disease relevant protein kinase targets using its proprietary integrated technology platform, including cell based assays and in vivo models. 4SC will apply its virtual High Throughput Screening technology, 4SCan® in combination with its medicinal chemistry capabilities. Identified lead candidate drugs will be synthesized and provided to ProQinase for biological screening and pharmacological testing.

“4SC, with its cost and time saving discovery process, represents an ideal partner to rapidly deliver validated lead drug candidates,’’ said Dr. Christoph Schächtele, Managing Director of ProQinase. “Our close proximity to the Tumor Biology Center in Freiburg will greatly facilitate taking these potential new cancer drugs into clinical trials.”

Under the terms of the agreement both collaboration partners will equally share resulting project rights from this collaboration.

About ProQinase

ProQinase is a biotech company focusing on the development of next-generation protein kinase inhibitors for cancer treatment. ProQinase developed the Integrated Technology Platform Protein Kinases and is using its platform for internal drug development programs as well as marketing parts of the platform to pharmaceutical and biotech companies worldwide.
The Integrated Technology Platform Protein Kinases features technologies for the identification and validation of protein kinases as novel targets for tumor therapy, more than 50 recombinant protein kinases, a robotic system for high-throughput screening and selectivity profiling of chemical substances, cellular test systems and in vivo tumor models.
ProQinase was founded in 2001 by the Tumor Biology Center, a privately owned Oncology Hospital in Freiburg, Germany. Currently 27 people work for ProQinase.

About 4SC

4SC is a drug discovery and development company that uses its cheminformatic based technological platform for the development of new drug candidates. By combining the disciplines of chemistry and biology with the proprietary virtual High Throughput Screening technology, 4SCan®, the time and cost of advancing a drug candidate to the development phase can be significantly reduced. The company’s therapeutic focus centers on infectious and hyperproliferative diseases. Five projects for the treatment of rheumatoid arthritis, cancer, transplantation, cystic fibrosis and ophthalmology are currently in preclinical evaluation and pharmacokinetics studies. 4SC, which was founded in 1997, today employs 80 people and is located in Martinsried, near Munich, Germany. For further information please visit www.4sc.com.