CORRECTING and REPLACING Gilead Sciences Announces Acceptance of Study 934 Late Breaker Abstract at 44th Annual ICAAC in Washington, DC

FOSTER CITY, Calif.--(BUSINESS WIRE)--Sept. 29, 2004--In BW5872 issued Sept. 29, 2004: First paragraph, first sentence of release should read: 44th Interscience Conference (sted 44th International Conference).

The corrected release reads:

GILEAD SCIENCES ANNOUNCES ACCEPTANCE OF STUDY 934 LATE BREAKER ABSTRACT AT 44TH ANNUAL ICAAC IN WASHINGTON, DC

Twenty-four Week Data Evaluating Viread(R) and Emtriva(R) Versus Combivir(R) in Combination with Efavirenz in Treatment-naive Patients with HIV to be Presented

Gilead Sciences (Nasdaq:GILD) today announced the acceptance of a late breaker presentation of 24-week interim data from the company's ongoing Study 934 at the 44th Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC) to be held in Washington, DC from October 30 to November 2, 2004. Study 934 compares a regimen of Viread(R) (tenofovir disoproxil fumarate), Emtriva(R) (emtricitabine) and efavirenz to Combivir(R) (lamivudine 150 mg/zidovudine 300 mg) and efavirenz in more than 500 treatment-naive patients with HIV. The study was recently extended to 96 weeks, with a 48-week primary endpoint.

Clinical investigator Brian Gazzard, MD, Chelsea and Westminster Hospital and Clinical Research Director, Imperial College, London, will present 24-week safety and efficacy data from Study 934 (Presentation #H-1137c) on Sunday, October 31, 2004 at 4:20 p.m. Eastern. Preliminary results from this study were summarized in a press release issued by Gilead on August 26, 2004. The data also have been accepted for presentation as an oral late breaker at the Seventh International Congress on Drug Therapy in HIV Infection to be held in Glasgow, Scotland from November 14-18, 2004.

A schedule of presentations may be obtained from the ICAAC website at www.ICAAC.org. Late breaker abstracts will be made available to conference participants upon registration at the meeting and will also be available from Gilead upon request at that time.

It is important that patients be aware that HIV medications must be taken as part of combination regimens and do not cure HIV infection, nor do they reduce its transmission.

About Viread

Viread is indicated in combination with other antiretroviral agents for the treatment of HIV-1 infection. This indication is based on analyses of plasma HIV-1 RNA levels and CD4 cell counts in controlled studies of Viread in treatment-naive adults and in treatment-experienced adults. There are no study results demonstrating the effect of Viread on clinical progression of HIV-1. The use of Viread should be considered for treating adult patients with HIV-1 strains that are expected to be susceptible to tenofovir as assessed by laboratory testing or treatment history.

Drug interactions have been observed when didanosine, atazanavir or lopinavir/ritonavir is co-administered with Viread and dose adjustments may be necessary. Data are not available to recommend a dose adjustment of didanosine for patients weighing less than 60 kg. Patients on atazanavir or lopinavir/ritonavir plus Viread should be monitored for Viread-associated adverse events which may require discontinuation.

Adverse events that occurred in more than 5 percent of patients receiving Viread with other antiretroviral agents in clinical trials include headache, nausea, diarrhea, vomiting, rash and depression. Less than 1 percent of patients discontinued participation because of gastrointestinal events. Renal impairment, including serious cases, has been reported. Renal impairment occurred most often in patients with underlying systemic or renal disease or in patients taking concomitant nephrotoxic agents, though some cases have appeared in patients without identified risk factors. Decreases in bone mineral density (BMD) at the lumbar spine and hip have been seen with the use of Viread. The clinical significance of changes in BMD and biochemical markers is unknown and follow-up is continuing to assess long-term impact.

About Emtriva

Emtriva is indicated, in combination with other antiretroviral agents, for the treatment of HIV-1 infection in adults. This indication is based on analyses of plasma HIV-1 RNA levels and CD4 cell counts from controlled studies of 48 weeks duration in antiretroviral treatment-naive patients and treatment-experienced patients who were virologically suppressed on an HIV treatment regimen. In treatment-experienced patients, the use of Emtriva may be considered for adults with HIV strains that are expected to be susceptible to Emtriva as assessed by genotypic or phenotypic testing.

Adverse events that occurred in more than 5 percent of patients receiving Emtriva with other antiretroviral agents in clinical trials include abdominal pain, asthenia (weakness), headache, diarrhea, nausea, vomiting, dizziness and rash. Approximately 1 percent of patients discontinued participation because of these events. All adverse events were reported with similar frequency in Emtriva and control treatment groups with the exception of skin discoloration which was reported with higher frequency in the Emtriva treated group. Skin discoloration, manifested by hyperpigmentation on the palms and/or soles, was generally mild and asymptomatic. The mechanism and clinical significance are unknown.

Important Safety Information

Lactic acidosis and severe hepatomegaly with steatosis, including fatal cases, have been reported with the use of nucleoside analogues alone or in combination with other antiretrovirals. Viread and Emtriva are not indicated for the treatment of chronic hepatitis B virus (HBV) infection and the safety and efficacy of these drugs has not been established in patients co-infected with HBV and HIV. Severe acute exacerbations of hepatitis B have been reported in patients who have discontinued Viread or Emtriva. Hepatic function should be monitored closely with both clinical and laboratory follow-up for at least several months in patients who discontinue Viread or Emtriva and are co-infected with HIV and HBV. If appropriate, initiation of anti-hepatitis B therapy may be warranted.

Changes in body fat have been observed in patients taking Viread, Emtriva and other anti-HIV medicines. The cause and long term health effect of these conditions are unknown.

About Gilead Sciences

Gilead Sciences is a biopharmaceutical company that discovers, develops and commercializes therapeutics to advance the care of patients suffering from life-threatening diseases worldwide. The company has seven marketed products, and focuses its research and clinical programs on anti-infectives. Headquartered in Foster City, CA, Gilead has operations in North America, Europe and Australia.

For full prescribing information, please visit www.Viread.com or www.Emtriva.com.

Viread and Emtriva are registered trademarks of Gilead Sciences, Inc.

For more information on Gilead Sciences, please visit the company's web site at www.gilead.com or call the Gilead Public Affairs Department at 1-800-GILEAD-5 or 1-650-574-3000.

CONTACT: Gilead Sciences, Inc. Susan Hubbard, 650-522-5715 (Investors) James Loduca, 650-522-5908 (Media) SOURCE: Gilead Sciences, Inc.