Flu Patients in United States May Now Have Access to Experimental Oral Treatment for Influenza

Eligible Volunteers May Enroll by Calling 1-888-I-GOT-FLU

Foster City, CA -- February 12, 1998

Adults in the United States with flu-like symptoms may now volunteer to participate in a clinical study testing a new experimental drug designed to treat influenza. Approximately 65 study sites across the country are now enrolling volunteers based on reports indicating that the cold and flu season is expected to peak over the next several weeks.

If people experience flu-like symptoms any time this winter, they can immediately call 1-888-I-GOT-FLU (1-888-446-8358) to determine if they are eligible to participate in this study. To be considered for the trial, volunteers must:

enroll within 36 hours of the first appearance of symptoms, including fever of at least 100¡F, one or more respiratory symptoms (cough, sore throat and nasal symptoms) and one or more constitutional symptoms (headache, malaise, aches and pains, chills or fatigue)
be between the ages of 18 and 65
not have had a flu vaccine within the past 12 months

Patients who enroll in the study may have free access to study drug, will receive a kit containing over-the-counter symptom relievers including acetaminophen and throat lozenges, and may be compensated for their time.

The investigational anti-flu drug, known as GS 4104, is an orally administered capsule that, in early human studies, decreased the duration and severity of symptoms associated with experimental influenza infection. GS 4104 is a potent and selective inhibitor of the influenza neuraminidase, an enzyme essential to the replication of all influenza strains.

Influenza infects an estimated 120 million people in the United States, Europe and Japan each year and is a major cause of morbidity and mortality. In periods of flu pandemics, infection rates can be even higher. Mortality is highest in people among high risk groups such as the elderly and those with heart and lung disorders. Currently marketed influenza treatments may be limited due to lack of activity against all influenza strains, adverse side-effect profiles and rapid development of resistance.

This study, which began in December 1997, is sponsored by the pharmaceutical companies Gilead Sciences, Inc. and F. Hoffmann-La Roche and is designed to be conducted at 73 clinics in the U.S. cities listed below.

Gilead Sciences is an independent biopharmaceutical company that seeks to provide accelerated treatment solutions for patients and the people who care for them. The Company discovers, develops and commercializes proprietary therapeutics for important viral diseases, including a currently marketed product, VISTIDE® (cidofovir injection), for the treatment of CMV retinitis, a sight-threatening viral infection in patients with AIDS. In addition, the Company is developing products to treat diseases caused by HIV, hepatitis B virus and influenza virus. Gilead common stock is traded on The Nasdaq Stock Market under the symbol GILD. For more information on Gilead, please visit our web site at www.gilead.com or contact: Lana Lauher, Gilead Sciences Corporate Communications, 650-573-4858.

Hoffmann-La Roche Inc. is a leading research-intensive pharmaceutical company that discovers, develops, manufactures and markets numerous important prescription drugs that improve, prolong and save the lives of patients with serious illnesses. Among the company1s areas of therapeutic interest are virology, including HIV and AIDS, infectious diseases, cardiology, oncology, transplantation, dermatology and obesity. The company provides a wide range of medications in the United States through its marketing and sales subsidiary, Roche Laboratories Inc. Headquartered in Nutley, NJ, both companies are members of the Basel, Switzerland-based Roche Group, a global leader in health care with principal businesses in pharmaceuticals, diagnostics, vitamins, and fragrances and flavors. For more information on Roche contact: Charles Alfaro, Hoffmann- La Roche Public Affairs, 973-562-2212.

Participating GS 4104 study sites are located in the following cities: