Incyte Genomics Receives Favorable Court Ruling Invalidating Affymetrix Patent Further Court Summary Judgement Decisions Hold Other Affymetrix Patent Claims Not Infringed by Incyte Palo Alto, CA, October 15, 2001 - Incyte Genomics, Inc. (Nasdaq:INCY), the leading genomics information company, announced today that the U.S. District Court for the Northern District of California has granted a victory to Incyte by issuing a summary judgement ruling on October 3, 2001 in favor of Incyte for the remaining two disputed claims of the "two-color" patent presently issued to Affymetrix. Over the past few months, there have been several recent summary judgement decisions in its patent litigation with Affymetrix, Inc. (Nasdaq:AFFX). Two of those decisions invalidate certain patent claims that Affymetrix has asserted against Incyte, and another holds that Incyte's commercially-available cDNA microarrays do not infringe other Affymetrix patent claims. The involved patents are U.S. Patent Nos. 5,800,992 (the '992 patent) 5,445,934 (the '934 patent), and 5,744,305 (the '305 patent). The '992 patent includes various claims to the use of two-color fluorescent labels to conduct various experiments using microarrays, including comparative gene expression analysis. The '934 patent includes claims covering certain types of oligonucleotide microarrays. The '305 patent includes claims to certain types of oligonucleotide arrays and polynucleotide arrays. In two recent decisions, the Federal District Court for the Northern District of California held that all of the claims in the '992 patent are invalid. In separate decisions, the court held that Incyte's cDNA arrays do not infringe any of the claims in either the '934 patent or the claims of the '305 patent that are directed to oligonucleotide arrays. As a consequence, the only remaining claims of the three patents that are potentially relevant to Incyte's commercially-available products are Affymetrix's claims in the '305 patent to specific types of polynucleotide arrays. Incyte has a pending motion for summary judgment that its cDNA arrays do not infringe these remaining claims, which is scheduled to be heard by the court on October 16, 2001, with a decision expected to follow sometime thereafter. In addition, Incyte has asserted several legal bases on which it believes the court should ultimately invalidate the claims of the '934 and '305 patents at trial, should a trial prove necessary. "The Court's ruling is a victory, not only for Incyte, but for the entire medical research community," commented Lee Bendekgey, Incyte's General Counsel. "Affymetrix has continually asserted that it owns the field of DNA arrays regardless of the method of manufacture and regardless of the uses to which those arrays are put. These rulings significantly scale back the scope of the Affymetrix' patent estate. We have maintained from the start that these claims have no merit, and we are confident that the District Court ruling will help to bring the relatively few remaining claims against Incyte to a successful conclusion for Incyte." Incyte Genomics, Inc. has developed one of the leading integrated platforms of genomic technologies designed to aid in the understanding of the molecular basis of disease. Incyte develops and markets genomic databases and partnership programs, genomic data management software, microarray-based gene expression services, related reagents and services. These products, programs and services assist pharmaceutical and biotechnology researchers with all phases of drug discovery and development including gene discovery, understanding disease pathways, identifying new disease targets and the discovery and correlation of gene sequence variation to disease. In addition, Incyte has the largest portfolio of issued United States patents covering human full-length genes and the proteins they encode and is leveraging its intellectual property position to be a leader in therapeutic discoveries. For more information, visit Incyte's web site at www.incyte.com. Except for the historical information contained herein, the matters set forth in this press release, (including without limitation statements as to the implications of the Court's rulings for Affymetrix and for other third parties and statements as to the ultimate outcome of any appeal or litigation in favor of Incyte, are forward-looking statements within the meaning of the "safe harbor" provisions of the Private Securities Litigation Reform Act of 1995. These forward-looking statements are subject to risks and uncertainties that may cause actual results to differ materially, including developments in the appeal process and in litigation. For a discussion of factors that may cause results to differ, see Incyte's SEC reports, including its Quarterly Report on Form 10-Q for the quarter ended June 30, 2001. Incyte disclaims any intent or obligation to update these forward-looking statements.