Gilead Sciences and GlaxoSmithKline Modify Terms of License Agreement for NX 211, Gilead's Investigational Compound for the Treatment of Cancer

Foster City, CA -- January 16, 2001

Gilead Sciences, Inc. (Nasdaq: GILD) today announced that the company and GlaxoSmithKline (NYSE: GSK) have modified their license agreement for NX 211, Gilead’s investigational compound for the treatment of cancer. Under the revised terms of the agreement, GlaxoSmithKline has waived its right to participate in the development and commercialization of NX 211, giving Gilead exclusive rights to the compound. Gilead and GlaxoSmithKline have also modified the financial terms of the license agreement by eliminating Gilead’s royalty obligations on product sales in exchange for one-time milestone payments that Gilead would pay to GlaxoSmithKline upon certain regulatory approvals of the product. The modification of the agreement between Gilead and GlaxoSmithKline was required for U.S. Federal Trade Commission clearance of the merger between Glaxo Wellcome and SmithKline Beecham.

NX 211 is a liposomal formulation of the anti-cancer agent lurtotecan. Gilead is currently evaluating NX 211 as a potential treatment for patients with recurrent ovarian cancer and small cell lung cancer. Three Phase II clinical trials have been initiated in these target indications. Gilead licensed worldwide rights to lurtotecan from Glaxo Wellcome in 1998. Lurtotecan functions by inhibiting topoisomerase I, an enzyme in the cell nucleus involved in the unwinding of DNA segments. By inhibiting topoisomerase I, NX 211 may prevent DNA from unwinding, thereby preventing cell replication.

Gilead Sciences, Inc., headquartered in Foster City, CA, is an independent biopharmaceutical company that seeks to provide accelerated solutions for patients and the people who care for them. Gilead discovers, develops, manufactures and commercializes proprietary therapeutics for challenging infectious diseases (viral, fungal and bacterial infections) and cancer. Gilead maintains research, development or manufacturing facilities in Foster City, CA; Boulder, CO; San Dimas, CA; Cambridge, UK and Dublin, Ireland and sales and marketing organizations in the United States, Europe and Australia. For more information about Gilead, please visit www.gilead.com.

GlaxoSmithKline – one of the world’s leading research-based pharmaceutical and healthcare companies – is committed to improving the quality of human life by enabling people to do more, feel better and live longer.

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For more information on Gilead Sciences, please call the Gilead Corporate Communications Department at 1-800-GILEAD-5 (1-800-445-3235).