Gilead Statement on Veklury® (Remdesivir) and the SARS-CoV-2 Omicron Variant

Foster City, Calif., December 1, 2021 – Gilead has conducted an analysis of genetic information currently available for the Omicron variant and found no additional prevalent mutations in the viral RNA polymerase compared to previous SARS-CoV-2 variants. This suggests that Veklury® (remdesivir) will continue to be active against the Omicron variant and Gilead will conduct laboratory testing to confirm this analysis.

Veklury directly inhibits the SARS-CoV-2 replication inside infected cells by targeting the viral RNA polymerase. Initial genetic analysis of more than 200 available sequences of the Omicron variant isolates, including those from South Africa, Asia and Europe, has shown that no new mutations are present in the Omicron variant that are expected to alter the SARS-CoV-2 viral RNA polymerase compared to previous variants. This suggests that Veklury will continue to be active against the Omicron variant and Gilead will continue to analyze additional genetic sequences of the Omicron variant as they become available. Gilead conducts these analyses to ensure rapid and transparent updates on the potential effectiveness of Veklury.

In addition to genetic analyses, Gilead continues to experimentally evaluate the activity of Veklury against identified SARS-CoV-2 variants through in vitro antiviral testing. Veklury’s antiviral activity has been confirmed in vitro against all major previously identified variants of SARS-CoV-2 including Alpha, Beta, Gamma, Delta, and Epsilon. Due to the similarities in the viral RNA polymerase, these laboratory findings suggest that Veklury will also continue to be active against the Omicron variant and Gilead will conduct laboratory testing to confirm this analysis.

Gilead is working with experts in governments and academia to obtain viral isolates and conduct in vitro laboratory testing of Veklury’s antiviral activity against the Omicron variant, which requires additional time. As soon as the testing is complete, Gilead will share the data with regulatory agencies, treating physicians and public health authorities.

To date, no major genetic changes have been identified in any of the known SARS-CoV-2 variants of concern and variants of interest that would significantly alter the viral RNA polymerase targeted by Veklury. In contrast, all identified variants show mutations at different locations in the SARS-CoV-2 spike protein, which is on the outer surface of the virus and serves as a target for all neutralizing anti-SARS-CoV-2 antibodies.

Veklury is approved or authorized for temporary use in approximately 50 countries worldwide. Veklury and generic remdesivir have been made available to nine million patients around the world, including 6.5 million people in 127 middle- and low-income countries through our voluntary licensing program.

Veklury is the antiviral standard of care for the treatment of people hospitalized with COVID-19. It can help reduce disease progression across the spectrum of disease severity and enable hospitalized patients to recover faster, freeing up limited hospital resources and saving healthcare systems money. Veklury is contraindicated in patients who are allergic to Veklury or any of its components; please see below for additional Important Safety Information for Veklury.

U.S. Indication for Veklury
Veklury^® (remdesivir 100 mg for injection) is indicated for adults and pediatric patients (12 years of age and older and weighing at least 40 kg) for the treatment of COVID-19 requiring hospitalization. Veklury should only be administered in a hospital or in a healthcare setting capable of providing acute care comparable to inpatient hospital care. Veklury is contraindicated in patients who are allergic to Veklury or any of its components. For more information, please see the U.S. full Prescribing Information available at www.gilead.com

U.S. Important Safety Information for Veklury

Contraindication
Veklury is contraindicated in patients with a history of clinically significant hypersensitivity reactions to Veklury or any of its components.

Warnings and precautions

• Hypersensitivity, including infusion-related and anaphylactic reactions: Hypersensitivity, including infusion-related and anaphylactic reactions, has been observed during and following administration of Veklury. Monitor patients under close medical supervision for hypersensitivity reactions during and following administration of Veklury. Symptoms may include hypotension, hypertension, tachycardia, bradycardia, hypoxia, fever, dyspnea, wheezing, angioedema, rash, nausea, diaphoresis, and shivering. Slower infusion rates (maximum infusion time ≤120 minutes) can potentially prevent these reactions. If a severe infusion-related hypersensitivity reaction occurs, immediately discontinue Veklury and initiate appropriate treatment (see Contraindications).
• Increased risk of transaminase elevations: Transaminase elevations have been observed in healthy volunteers and in patients with COVID-19 who received Veklury; these elevations have also been reported as a clinical feature of COVID-19. Perform hepatic laboratory testing in all patients (see Dosage and administration). Consider discontinuing Veklury if ALT levels increase to >10x ULN. Discontinue Veklury if ALT elevation is accompanied by signs or symptoms of liver inflammation.
• Risk of reduced antiviral activity when coadministered with chloroquine or hydroxychloroquine: Coadministration of Veklury with chloroquine phosphate or hydroxychloroquine sulfate is not recommended based on data from cell culture experiments, demonstrating potential antagonism, which may lead to a decrease in antiviral activity of Veklury.

Adverse reactions

• The most common adverse reaction (≥5% all grades) was nausea.
• The most common lab abnormalities (≥5% all grades) were increases in ALT and AST.

Drug interactions

• Drug interaction trials of Veklury and other concomitant medications have not been conducted in humans.

Dosage and administration

• Dosage: For adults and pediatric patients ≥12 years old and weighing ≥40 kg: 200 mg on Day 1, followed by once-daily maintenance doses of 100 mg from Day 2 administered only via intravenous infusion over 30 to 120 minutes.
• Treatment duration: For patients not requiring invasive mechanical ventilation and/or extracorporeal membrane oxygenation (ECMO): 5 days; may be extended up to 5 additional days (10 days total) if clinical improvement is not observed. For patients requiring invasive mechanical ventilation and/or ECMO: 10 days.
• Testing prior to and during treatment: Perform eGFR, hepatic laboratory, and prothrombin time testing prior to initiating Veklury and during use as clinically appropriate.
• Renal impairment: Veklury is not recommended in individuals with eGFR <30 mL/min.
• Dose preparation and administration: See full Prescribing Information.

Pregnancy and lactation

• Pregnancy: There are insufficient human data on the use of Veklury during pregnancy. Pregnant women hospitalized with COVID-19 are at risk for serious morbidity and mortality. Veklury should be used during pregnancy only if the potential benefit justifies the potential risk for the mother and the fetus.
• Lactation: It is not known whether Veklury can pass into breast milk. Breastfeeding individuals with COVID-19 should follow practices according to clinical guidelines to avoid exposing the infant to COVID-19.

About Gilead Sciences
Gilead Sciences, Inc. is a biopharmaceutical company that has pursued and achieved breakthroughs in medicine for more than three decades, with the goal of creating a healthier world for all people. The company is committed to advancing innovative medicines to prevent and treat life-threatening diseases, including HIV, viral hepatitis and cancer. Gilead operates in more than 35 countries worldwide, with headquarters in Foster City, California.

Forward-Looking Statements
This press release includes forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995 that are subject to risks, uncertainties and other factors, including the pending in vitro testing of the effectiveness of Veklury against the SARS-CoV-2 Omicron variant. There is the possibility that Veklury may not be effective against the Omicron variant or future variants of SARS-CoV-2. In the addition, there is the possibility of unfavorable results from ongoing or additional clinical studies involving Veklury. These and other risks, uncertainties and factors are described in detail in Gilead’s Quarterly Report on Form 10-Q for the quarter ended September 30, 2021, as filed with the U.S. Securities and Exchange Commission. These risks, uncertainties and other factors could cause actual results to differ materially from those referred to in the forward-looking statements. All statements other than statements of historical fact are statements that could be deemed forward-looking statements. The reader is cautioned that any such forward-looking statements are not guarantees of future performance and is cautioned not to place undue reliance on these forward-looking statements. All forward-looking statements are based on information currently available to Gilead, and Gilead assumes no obligation and disclaims any intent to update any such forward-looking statements.

U.S. full Prescribing Information for Veklury is available at www.gilead.com.

Veklury, Gilead and the Gilead logo are registered trademarks of Gilead Sciences, Inc., or its related companies.

For more information about Gilead, please visit the company’s website at www.gilead.com, follow Gilead on Twitter (@Gilead Sciences) or call Gilead Public Affairs at 1-800-GILEAD-5 or 1-650-574-3000.