Gilead Donates Remdesivir for Ebola Clinical Trial in the Democratic Republic of the Congo

Foster City, Calif., October 8, 2025 – Gilead Sciences announced today that it will donate 1,100 vials of remdesivir for a clinical trial testing investigational treatments for Ebola disease in the Democratic Republic of the Congo (DRC).

“Gilead’s rapid pandemic response stems from a strong innovation ecosystem in infectious diseases, backed by our commitment to accelerate transformative medicine development. These pillars are critical to building public health resilience,” said Anu Osinusi, Vice President of Clinical Research for Hepatitis, Respiratory and Emerging Viruses at Gilead Sciences. “We are actively collaborating with government agencies, healthcare systems, academic institutions, non-profits, and frontline researchers to share insights and strengthen the public health response to this outbreak. The swift launch of this clinical trial reflects the strength of our strategic global partnerships, our continued commitment to pandemic preparedness and the potential of U.S.-driven innovations like remdesivir to support research efforts.”

Over the past decade, remdesivir has been donated for emergency and compassionate use as a part of numerous responses to filovirus outbreaks in Sub-Saharan Africa, as well as for investigational use in clinical trials. The most recent example are the donations made in response to the Marburg Virus Disease (MVD) outbreaks in Tanzania and Rwanda. The current donation will be directed to the World Health Organization (WHO), which will collaborate on a clinical trial with the government of the DRC and other partners.

Remdesivir is not licensed for the treatment of Ebola anywhere globally, and the safety and efficacy of remdesivir for this use is not known.

Remdesivir is a nucleotide analog prodrug invented and developed by Gilead, building on more than a decade of the company’s antiviral research. Remdesivir has shown broad-spectrum antiviral activity both in vitro and in animal models against multiple viral pathogens, including Ebola virus and Marburg virus, SARS-CoV, MERS and SARS-CoV-2, the virus that causes COVID-19.

Remdesivir, which is sold under the tradename Veklury® has been approved as a COVID-19 treatment in approximately 50 countries worldwide. To date, remdesivir has been made available to more than 14.5 million COVID-19 patients around the world, including more than 8 million people in middle- and low-income countries through Gilead’s voluntary licensing program.

The clinical efficacy of remdesivir for Ebola remains to be established. This donation of remdesivir for use in the clinical trial is based on the preclinical data for Ebola together with extensive clinical safety data from the use of remdesivir for the treatment of COVID-19.

U.S. Indication for Veklury

VEKLURY is indicated for the treatment of COVID-19 in adults and pediatric patients (≥28 days old and weighing ≥3 kg) who are:

• Hospitalized, or
• Not hospitalized, have mild-to-moderate COVID-19, and are at high risk for progression to severe COVID-19, including hospitalization or death.

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; most occurred within one hour. Monitor patients during infusion and observe for at least one hour after infusion is complete for signs and symptoms of hypersensitivity as clinically appropriate. Symptoms may include hypotension, hypertension, tachycardia, bradycardia, hypoxia, fever, dyspnea, wheezing, angioedema, rash, nausea, diaphoresis, and shivering. Slower infusion rates (maximum infusion time up to 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

• Administration should take place under conditions where management of severe hypersensitivity reactions, such as anaphylaxis, is possible.
• Treatment duration:
  • For patients who are hospitalized, Veklury should be initiated as soon as possible after diagnosis of symptomatic COVID-19.
  • For patients who are hospitalized and do not require invasive mechanical ventilation and/or ECMO, the recommended treatment duration is 5 days. If a patient does not demonstrate clinical improvement, treatment may be extended up to 5 additional days, for a total treatment duration of up to 10 days.
  • For patients who are hospitalized and require invasive mechanical ventilation and/or ECMO, the recommended total treatment duration is 10 days.
  • For patients who are not hospitalized, diagnosed with mild-to-moderate COVID-19, and are at high risk for progression to severe COVID-19, including hospitalization or death, the recommended total treatment duration is 3 days. Veklury should be initiated as soon as possible after diagnosis of symptomatic COVID-19 and within 7 days of symptom onset for outpatient use.
• Testing prior to and during treatment: Perform hepatic laboratory and prothrombin time testing prior to initiating Veklury and during use as clinically appropriate.
• Renal impairment: No dosage adjustment of Veklury is recommended in patients with any degree of renal impairment, including patients on dialysis. Veklury may be administered without regard to the timing of dialysis.

Pregnancy and lactation

• Pregnancy: A pregnancy registry has been established for Veklury Available clinical trial data for Veklury in pregnant women have not identified a drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes following second- and third- trimester exposure. There are insufficient data to evaluate the risk of Veklury exposure during the first- trimester. Maternal and fetal risks are associated with untreated COVID-19 in pregnancy.
• Lactation: Veklury can pass into breast milk. The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for Veklury and any potential adverse effects on the breastfed child from Veklury or from an underlying maternal condition. 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, COVID-19, cancer and inflammation. Gilead operates in more than 35 countries worldwide, with headquarters in Foster City, California.

Forward-Looking Statements

This company statement 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 Gilead’s ability to effectively manage the supply and distribution of Veklury (remdesivir); Gilead’s ability to initiate, progress or complete clinical trials within currently anticipated timelines or at all, and the possibility of unfavorable results from ongoing or additional clinical trials, including those involving Veklury; and any assumptions underlying any of the foregoing. These and other risks, uncertainties and factors are described in detail in Gilead’s Quarterly Report on Form 10-Q for the quarter ended June 30, 2025, 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 involve risks and uncertainties 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 X/Twitter (@Gilead Sciences) and LinkedIn (@Gilead-Sciences).