press release archive

Rigel Acquires Technology From Leading Research Institutions to Advance Genomic Target Discovery Programs

South San Francisco, Calif. - February 21, 2002

Rigel Pharmaceuticals, Inc. (Nasdaq: RIGL) today announced that the Company has signed agreements with The Pennsylvania State University and Oklahoma Medical Research Foundation to license from these institutions new intellectual property and technology complementary to the Company’s current research and development programs.

Rigel has in-licensed the SICLOPPS, or cyclic peptide, technology from Penn State that will help enable the Company to develop intracellular cyclic peptide libraries. Peptide libraries are key sources of diversity for identifying and developing new therapeutics such as peptides or small molecule drugs. Rigel plans to incorporate this technology into its existing functional genomics and target discovery and validation infrastructure.

Rigel has also in-licensed the patent estate to the RBX, or ROC1, protein from the Oklahoma Medical Research Foundation. This protein is an ubiquitin ligase target with potential therapeutic importance in both oncology and inflammatory disease – two areas in which Rigel is already developing product candidates. Ubiquitin ligases comprise a new class of targets with roles in most disease states. Rigel has already initiated high-throughput screening with this ubiquitin ligase target.

“We believe that both of these agreements enhance Rigel’s position as a leader in target discovery and development,” said Brian C. Cunningham, Rigel’s president and chief operating officer. “The new ligase intellectual property strengthens our growing leadership in the ubiquitin ligase area, a field that we believe holds tremendous potential as a source for regulating cell function across a variety of disease states.”

About Rigel Pharmaceuticals, Inc.
Rigel Pharmaceuticals (www.rigel.com) is a drug discovery and development company that uses advanced functional genomics tools to discover novel drug targets that can be used to develop orally administered small molecule drugs. Rigel's technology is designed to identify molecules that play an important role in regulating a human cell's response to disease by testing a very large number of proteins in a very large number of cells to determine which proteins will change the cell's response to the disease. Rigel expects to begin clinical trials during 2002 with one or more new drug candidates identified from the ten current product development programs in the areas of asthma/allergy, autoimmunity, transplant rejection, rheumatoid arthritis, inflammatory bowel disease, chronic bronchitis, cancerous tumor growth and hepatitis C. Rigel has collaborations with Pfizer Inc., Cell Genesys, Inc., Johnson & Johnson Pharmaceutical Research & Development, L.L.C. and Novartis Pharma A.G. Rigel is based in South San Francisco, California.

This press release contains "forward-looking" statements, including statements related to anticipated use of in-licensed technologies, anticipated development and success of target discovery and validation efforts and the Company's plans to commence clinical trials in 2002. Any statements contained in this press release that are not statements of historical fact may be deemed to be forward-looking statements. Words such as "believes," "anticipates," "plans," "expects," "will" and similar expressions are intended to identify forward-looking statements. There are a number of important factors that could cause the results of the Company to differ materially from those indicated by these forward-looking statements, including the risks detailed from time to time in the Company's SEC reports, including its Annual Report on Form 10-K for the year ended December 31, 2000, as amended, and its most recent Quarterly Report on Form 10-Q. The Company does not undertake any obligation to update forward-looking statements