Gilead to Spotlight New Virology Data Across HIV, Viral Hepatitis and Respiratory Diseases at IDWeek 2025

– Additional Phase 3 PURPOSE Data Reinforce the Safety Profile of Twice-Yearly Yeztugo® as an Effective HIV Prevention Option Across Diverse Populations –

– New Data Show Higher Treatment Satisfaction After Switching from IM CAB+RPV to Biktarvy^® –

– New Research Reaffirms Veklury^® in High-Risk COVID-19 Populations and Obeldesivir in Emerging Pathogens –

FOSTER CITY, Calif.–(BUSINESS WIRE)–Gilead Sciences, Inc. (Nasdaq: GILD) will present new findings from its antiviral research and development programs at IDWeek, taking place October 19-22 in Atlanta, GA. Data from 34 presentations across HIV, respiratory viruses, viral hepatitis, and viruses of pandemic potential including six oral presentations underscore Gilead’s leadership in advancing antiviral science and its ongoing efforts to bring forward innovative solutions for people and communities most affected by infectious diseases.

“At IDWeek 2025, we look forward to presenting new data that reflect our ongoing commitment to developing transformational medicines for hepatitis, as well as HIV prevention and treatment, and to expanding that goal to respiratory and other viruses causing serious disease,” said Jared Baeten, MD, PhD, Senior Vice President, Virology Therapeutic Area Head, Gilead Sciences. “These studies highlight the strength and depth of our antiviral portfolio and expanding pipeline, and our focus on person-centered innovation to help address the diverse and evolving needs of people and communities affected by serious viral diseases in the U.S. and around the world.”

HIV Prevention Research

New pivotal PURPOSE 1 (NCT04994509) and PURPOSE 2 (NCT04925752) data provided further insight into the safety of twice-yearly Yeztugo^® (lenacapavir – or LEN) for pre-exposure prophylaxis (PrEP). Sub-analyses among PURPOSE 1 trial participants using progestin-type long-acting (LA) hormonal contraceptives (implants or injections) and PURPOSE 2 trial participants using gender-affirming hormone therapy (GAHT) showed no clinically significant drug-drug interactions between Yeztugo and these commonly-used products.

Findings from PURPOSE 2 also assessed Yeztugo adherence and safety among individuals who reported using stimulants and opioids. These data – from the most gender-diverse HIV prevention trial to date – underscore Yeztugo’s potential as an inclusive PrEP option for populations disproportionately affected by substance use, which can influence adherence.

HIV Treatment Research

As part of Gilead’s ongoing mission to help end the HIV epidemic through innovation, partnership, and equitable access, new data presented at IDWeek underscore the company’s deep commitment to delivering person-centered solutions that meet the evolving needs of people living with HIV. These include new findings that further reinforce the strong clinical profile of Biktarvy^® (bictegravir/emtricitabine/tenofovir alafenamide, B/F/TAF) as a leading standard of care for people with HIV, with data showing greater patient preference for Biktarvy over intramuscular cabotegravir + rilpivirine (IM CAB+RPV).

• In a 12-week interim analysis of the Phase 4 EMPOWER study (NCT06104306), individuals who switched from IM CAB+RPV to once-daily Biktarvy maintained viral suppression with no treatment-related serious adverse events and reported an increase in treatment satisfaction scores, citing higher satisfaction with side effects of their treatment.

Other treatment data include:

• Complementary findings from a large, multicountry HIV treatment survey (Canada, Mexico, U.S.) highlighted that while most people on antiretroviral therapy report satisfaction with durability, safety, and tolerability, a substantial proportion delay initiating or re-engaging in treatment due to fear of side effects, needing time to accept their diagnosis, or physician guidance.
• An analysis of IQVIA data revealed persistent geographic disparities in HIV specialist availability, with the U.S. requiring an additional 1,565 providers to meet UNAIDS’ 90-90-90 targets, particularly in the South where shortages are most acute. Achieving these targets – which call for 90% of people with HIV to be diagnosed, 90% of those diagnosed to receive treatment, and 90% of those treated to achieve viral suppression – will depend on addressing these gaps. These findings highlight the need for equitable access to care alongside therapeutic innovation.

Respiratory Viruses / COVID-19 Research

Gilead will present a comprehensive set of data across respiratory viruses, emphasizing the needs of populations most vulnerable to SARS-CoV-2 and respiratory syncytial virus (RSV). Key findings include:

• New analyses of Veklury^® (remdesivir) from the Phase 3 REDPINE (NCT04745351) study, which investigated viral load dynamics in individuals hospitalized with COVID-19 who have severely impaired renal function or have undergone solid organ transplantation – two groups at elevated risk for prolonged infection.
• Complementary real-world evidence will further illuminate treatment patterns among older adults with compromised health and immunocompromised individuals hospitalized with COVID-19 in the U.S., highlighting persistent gaps in care and areas of unmet needs.

Overview of Scientific Presentations

HIV Prevention Research
Presentation 392	Favorable Adherence and Safety of Twice-Yearly Subcutaneous Lenacapavir for PrEP Among PURPOSE 2 Participants Who Used Substances
Presentation 390	Lenacapavir Adherence and Effectiveness Over 2 Years of Use in the OPERA Cohort
P-299	No Clinically Significant Drug-Drug Interactions Between Lenacapavir and Hormonal Contraceptives in PURPOSE 1
P-305	No Clinically Significant Drug-Drug Interactions with Co-administration of Feminizing or Masculinizing Hormone Therapy and Twice-yearly Lenacapavir PrEP in Gender-Diverse Persons
P-382	PrEP Utilization Patterns and Indications in a Cohort of HIV-Negative Individuals
P-326	Barriers to Oral HIV Pre-Exposure Prophylaxis (PrEP) Perceived by Those Receiving an Initial Prescription: US Survey Analysis
P-287	Real-World Sexually Transmitted Infection (STI) Testing Patterns Among Individuals Using PrEP for HIV-1 Prevention in the United States
HIV Treatment Research
P-357	Geographic Variations of HIV Specialist Shortages: An Observational Study to Support the 90-90-90 HIV Treatment Goals in the US
P-382	Characteristics and Outcomes of People with HIV (PWH) with Suboptimal Adherence on B/F/TAF or Dolutegravir Single-Tablet Regimens (STRs)
P-386	A Phase 4 Study to Evaluate the Safety and Efficacy of Oral B/F/TAF After Discontinuing Injectable CAB + RPV
P-387	Evaluation of Treatment Satisfaction and Experiences Among People With HIV When Switching to Bictegravir/Emtricitabine/Tenofovir Alafenamide From Cabotegravir + Rilpivirine: Results From the Phase 4 EMPOWER Study
P-390	Persistence and Adherence of PWH and Mental Health Disorder Diagnosis who Restart Antiretroviral Therapy (ART)
P-391	Impact of Rapid Antiretroviral Therapy Initiation on Retention in Care and Viral Suppression in an urban HIV clinic in Louisville, Kentucky
P-393	Treatment Switch among Medicare-insured People with HIV and Gaps in Care
P-394	Antiretroviral Therapy Persistence Following a Change or Restart in Regimen Among People with HIV
P-2034	Evaluation of Implementing Text-Messaging Based Medication Reminders to Improve Adherence to Antiretrovirals in People Living with HIV
P-2043	Improving Access and Adherence to Antiretroviral Therapy Through Coordinated Outreach and Care Linkage Model: A Collaborative Program Evaluation
P-2071	Reaching the Hard-to-Reach ACCELERATE Model of HIV Care: Telehealth, Rapid Restart, Follow-up
P-2084	HIV Viewpoints: Survey on the Experiences of People Living with HIV in North America
Respiratory, Hepatitis, and Pandemic Viruses
P-1276	Remdesivir And Obeldesivir Retain Potent Activity Against SARS-CoV-2 Omicron Variants
P-1625	SARS-CoV-2 Viral Load Dynamics in Participants With Solid Organ Transplantation and Severely Reduced Kidney Function From the Remdesivir Phase 3 REDPINE Study Who Were Hospitalized for COVID-19
P-1632	Effectiveness of Remdesivir in Patients With Underlying Hepatic or Renal Comorbidity Hospitalized For SARS-CoV-2 Infection
P-661	Treatment Patterns Observed Among Immunocompromised and Frail Hospitalized COVID-19 Patients in the US
P-1232	Dose Selection of Obeldesivir for Clinical Evaluation in Treatment of Adult Participants with Respiratory Syncytial Virus Infection
P-1231	A Phase 1 Open-label, Parallel-group, Single-dose Study to Evaluate the Pharmacokinetics and Safety of Obeldesivir in Participants with Normal Renal Function and Renal Impairment
P-1169	Obeldesivir and GS-441524 Antiviral Activity against L Protein Mutants in Respiratory Syncytial Virus (RSV) Minigenome and Recombinant Infectious Virus Systems
P-686	Evolving Patterns Of Testing For Respiratory Syncytial Virus In The United States: Who Is Getting Tested?
P-1166	Obeldesivir Clinical Dose Projection for Marburg Virus Disease Post-Exposure Prophylaxis
P-2195	Influence of Nucleos(t)ide Analogue Use With Bulevirtide on Treatment Outcomes in Chronic Hepatitis Delta

For more information about Gilead’s presence at IDWeek 2025, including a complete list of abstracts and their corresponding oral and poster sessions, please visit https://idweek.org/program/.

Lenacapavir for HIV prevention is not approved by any regulatory authority outside of U.S. or EU.

Please see below for U.S. Indication and Important Safety Information, including Boxed Warning, for Biktarvy and Yeztugo. Please also see below for the U.S. Indication and Important Safety Information for Veklury.

There is currently no cure for HIV or AIDS.

The use of obeldesivir is investigational and has not been determined to be safe or efficacious and is not approved by the FDA.

Bulevirtide 2 mg remains the only approved treatment for adults with chronic HDV and compensated liver disease in the European Economic Area (EEA), the UK, Canada, Australia and is not approved in the U.S. Bulevirtide 10 mg is an investigational product and is not approved anywhere.

About Lenacapavir

Lenacapavir is approved in multiple countries as pre-exposure prophylaxis (PrEP) to reduce the risk of sexually acquired HIV in adults and adolescents who are at risk of HIV acquisition. Lenacapavir is also approved in multiple countries for the treatment of multi-drug-resistant HIV in adults, in combination with other antiretrovirals.

The multi-stage mechanism of action of lenacapavir is distinguishable from other currently approved classes of antiviral agents. While most antivirals act on just one stage of viral replication, lenacapavir is designed to inhibit HIV at multiple stages of its lifecycle and has no known cross resistance exhibited in vitro to other existing drug classes.

Lenacapavir is being evaluated as a long-acting option in multiple ongoing and planned early and late-stage clinical studies in Gilead’s HIV prevention and treatment research program. Lenacapavir is being developed as a foundation for potential future HIV therapies with the goal of offering both long-acting oral and injectable options with several dosing frequencies, in combination or as a mono agent, that help address individual needs and preferences of people and communities affected by HIV. The journal Science named lenacapavir its 2024 “Breakthrough of the Year.”

About Biktarvy

Biktarvy is a complete HIV treatment that combines three powerful medicines to form the smallest 3-drug, integrase strand transfer inhibitor (INSTI)-based STR available, offering simple once-daily dosing with or without food, with a limited drug interaction potential and a high barrier to resistance. Biktarvy combines the novel, unboosted INSTI bictegravir, with the F/TAF backbone. Biktarvy is a complete STR and should not be taken with other HIV medicines.

About Veklury

Veklury (remdesivir) is a nucleotide analog prodrug invented by Gilead, building on more than a decade of the company’s antiviral research. Veklury is the antiviral standard of care for the treatment of hospitalized patients with COVID-19 and is a recommended treatment for reducing disease progression in non-hospitalized patients at high risk of disease progression. Veklury is the only antiviral studied in hospitalized COVID-19 patients in clinical trials and large real-world analyses that has demonstrated reduced time to recovery, as well as disease progression, mortality and readmission.

Veklury directly inhibits viral replication inside of the cell by targeting the SARS-CoV-2 viral RNA polymerase. Based on in vitro analyses, Veklury retains antiviral activity against recent Omicron subvariants of concern, including XBF, XBB.1.16, FL.22, E.G.5.1 and BA.2.86. Veklury continues to be evaluated against emerging variants of interest and concern.

Veklury is approved in more than 50 countries worldwide. To date, Veklury and generic remdesivir have been made available to approximately 14.5 million patients around the world, including more than 8.1 million people in middle- and low-income countries through Gilead’s voluntary licensing program.

U.S. Indication for Yeztugo

Yeztugo (lenacapavir) injection, 463.5 mg/1.5 mL, is indicated for pre‑exposure prophylaxis (PrEP) to reduce the risk of sexually acquired HIV-1 in adults and adolescents ( ≥ 35kg) who are at risk for HIV-1 acquisition. Individuals must have a negative HIV-1 test prior to initiating Yeztugo.

U.S. Important Safety Information for Yeztugo

BOXED WARNING: RISK OF DRUG RESISTANCE WITH USE OF YEZTUGO IN UNDIAGNOSED HIV-1 INFECTION

• Individuals must be tested for HIV-1 infection prior to initiating Yeztugo, and with each subsequent injection of Yeztugo, using a test approved or cleared by the FDA for the diagnosis of acute or primary HIV-1 infection. Drug-resistant HIV-1 variants have been identified with use of Yeztugo by individuals with undiagnosed HIV-1 infection. Do not initiate Yeztugo unless negative infection status is confirmed. Individuals who acquire HIV-1 while receiving Yeztugo must transition to a complete HIV-1 treatment regimen.

Contraindications

• Yeztugo is contraindicated in individuals with unknown or positive HIV-1 status.

Warnings and precautions

• Comprehensive risk management:
  • Use Yeztugo to reduce the risk of HIV-1 acquisition as part of a comprehensive prevention strategy including adherence to the administration schedule and safer sex practices, including condoms, to reduce the risk of sexually transmitted infections (STIs).
  • HIV-1 acquisition risk includes behavioral, biological, or epidemiologic factors including, but not limited to, condomless sex, past or present STIs, self-identified HIV risk, having sexual partners of unknown HIV-1 viremic status, or sexual activity in a high-prevalence area or network. Counsel individuals on the use of other prevention methods to help reduce their risk.
  • Use Yeztugo only in individuals confirmed to be HIV-1 negative. Evaluate for current or recent signs or symptoms consistent with HIV-1 infection. Confirm HIV-1 negative status prior to initiating, prior to each subsequent injection, and as clinically appropriate.
• Potential risk of resistance:
  • There is a potential risk of developing resistance to Yeztugo if an individual acquires HIV-1 before or when receiving Yeztugo, or following discontinuation. HIV- 1 resistance substitutions may emerge in individuals with undiagnosed HIV-1 infection taking only Yeztugo, because Yeztugo alone is not a complete regimen for HIV-1 treatment.
  • To minimize this risk, it is essential to test before each injection and additionally as clinically appropriate. Individuals confirmed to have HIV-1 must immediately begin a complete HIV-1 treatment regimen.
  • Alternative forms of PrEP should be considered after discontinuation of Yeztugo for those who are at continuing risk of HIV-1 acquisition and should be initiated within 28 weeks of the last Yeztugo injection.
• Long-acting properties and potential associated risks:
  • Residual concentrations of Yeztugo may remain in systemic circulation for up to 12 months or longer after the last injection.
  • Select individuals who agree to the required injection dosing schedule because nonadherence or missed doses could lead to HIV-1 acquisition and development of resistance.
• Serious injection site reactions: Improper administration (intradermal injection) has been associated with serious injection site reactions, including necrosis and ulcer. Only administer Yeztugo subcutaneously.

Adverse reactions

• Most common adverse reactions (≥5%) in Yeztugo clinical trials were injection site reactions, headache, and nausea.

Drug interactions

• Strong or moderate CYP3A inducers may significantly decrease Yeztugo concentrations. Dosage modifications are recommended when initiating these inducers.
• It is not recommended to use Yeztugo with combined P-gp, UGT1A1, and strong CYP3A inhibitors.
• Coadministration of Yeztugo with sensitive substrates of CYP3A or P-gp may increase their concentrations and result in the increased risk of their adverse events. Yeztugo may increase the exposure of drugs primarily metabolized by CYP3A initiated within 9 months after the last injection of Yeztugo.

Dosage and administration

• HIV screening: Test for HIV-1 infection prior to initiating, prior to each subsequent injection, and as clinically appropriate using an approved or cleared test for the diagnosis of acute or primary HIV-1 infection.
• Dosage: Initiation dosing (injections and tablets) followed by once-every-6-months continuation injection dosing. Tablets may be taken with or without food.
  • Initiation: Day 1: 927 mg by subcutaneous injection (2 x 1.5-mL injections) and 600 mg orally (2 x 300-mg tablets). Day 2: 600 mg orally.
  • Continuation: 927 mg by subcutaneous injection every 6 months (26 weeks) from date of last injection ±2 weeks.
• Anticipated delayed injections: If scheduled 6-month injection is anticipated to be delayed by more than 2 weeks, Yeztugo tablets may be taken on an interim basis (for up to 6 months) until injections resume. Dosage is 300 mg orally (1 x 300-mg tablet) once every 7 days. Resume continuation injections within 7 days of the last oral dose.
• Missed injections: If more than 28 weeks have elapsed since the last injection and Yeztugo tablets have not been taken, restart with initiation dosing if clinically appropriate.
• Dosage modifications of Yeztugo are recommended when initiating with strong or moderate CYP3A inducers. Consult the full Prescribing Information for recommendations.

U.S. Indication for Biktarvy

BIKTARVY is indicated as a complete regimen for the treatment of HIV-1 infection in adult and pediatric patients weighing ≥14 kg with no antiretroviral treatment history; or with an ARV treatment history and not virologically suppressed, with no known or suspected substitutions associated with resistance to the integrase strand inhibitor class, emtricitabine, or tenofovir; or to replace the current ARV regimen in those who are virologically suppressed (HIV-1 RNA <50 copies per mL) on a stable ARV regimen with no known or suspected substitutions associated with resistance to bictegravir or tenofovir.

U.S. Important Safety Information for Biktarvy

BOXED WARNING: POST TREATMENT ACUTE EXACERBATION OF HEPATITIS B

• Severe acute exacerbations of hepatitis B have been reported in patients who are coinfected with HIV-1 and HBV and have discontinued products containing emtricitabine (FTC) and/or tenofovir disoproxil fumarate (TDF), and may occur with discontinuation of BIKTARVY. Closely monitor hepatic function with both clinical and laboratory follow-up for at least several months in patients who are coinfected with HIV-1 and HBV and discontinue BIKTARVY. If appropriate, anti-hepatitis B therapy may be warranted.

Contraindications

• Coadministration: Do not use BIKTARVY with dofetilide or rifampin.

Warnings and precautions

• Drug interactions: See Contraindications and Drug Interactions sections. Consider the potential for drug interactions prior to and during BIKTARVY therapy and monitor for adverse reactions.
• Immune reconstitution syndrome, including the occurrence of autoimmune disorders with variable time to onset, has been reported.
• New onset or worsening renal impairment: Postmarketing cases of renal impairment, including acute renal failure, proximal renal tubulopathy (PRT), and Fanconi syndrome have been reported with tenofovir alafenamide (TAF)–containing products. Do not initiate BIKTARVY in patients with estimated creatinine clearance (CrCl) <30 mL/min except in virologically suppressed adults <15 mL/min who are receiving chronic hemodialysis. Patients with impaired renal function and/or taking nephrotoxic agents (including NSAIDs) are at increased risk of renal-related adverse reactions. Discontinue BIKTARVY in patients who develop clinically significant decreases in renal function or evidence of Fanconi syndrome.
  
  Renal monitoring: Prior to or when initiating BIKTARVY and during therapy, assess serum creatinine, CrCl, urine glucose, and urine protein in all patients as clinically appropriate. In patients with chronic kidney disease, assess serum phosphorus.
• Lactic acidosis and severe hepatomegaly with steatosis: Fatal cases have been reported with the use of nucleoside analogs, including FTC and TDF. Discontinue BIKTARVY if clinical or laboratory findings suggestive of lactic acidosis or pronounced hepatotoxicity develop, including hepatomegaly and steatosis in the absence of marked transaminase elevations.

Adverse reactions

• Most common adverse reactions (incidence ≥5%; all grades) in clinical studies through week 144 were diarrhea (6%), nausea (6%), and headache (5%).

Drug interactions

• Prescribing information: Consult the full prescribing information for BIKTARVY for more information on Contraindications, Warnings, and potentially significant drug interactions, including clinical comments.
• Enzymes/transporters: Drugs that induce P-gp or induce both CYP3A and UGT1A1 can substantially decrease the concentration of components of BIKTARVY. Drugs that inhibit P-gp, BCRP, or inhibit both CYP3A and UGT1A1 may significantly increase the concentrations of components of BIKTARVY. BIKTARVY can increase the concentration of drugs that are substrates of OCT2 or MATE1.
• Drugs affecting renal function: Coadministration of BIKTARVY with drugs that reduce renal function or compete for active tubular secretion may increase concentrations of FTC and tenofovir and the risk of adverse reactions.

Dosage and administration

• Dosage: Adult and pediatric patients weighing ≥25 kg: 1 tablet containing 50 mg bictegravir (BIC), 200 mg emtricitabine (FTC), and 25 mg tenofovir alafenamide (TAF) taken once daily with or without food. Pediatric patients weighing ≥14 kg to <25 kg: 1 tablet containing 30 mg BIC, 120 mg FTC, and 15 mg TAF taken once daily with or without food. For children unable to swallow a whole tablet, the tablet can be split and each part taken separately as long as all parts are ingested within approximately 10 minutes.
• Renal impairment: For patients weighing ≥25 kg, not recommended in patients with CrCl 15 to <30 mL/min, or <15 mL/min who are not receiving chronic hemodialysis, or <15 mL/min who are receiving chronic hemodialysis and have no antiretroviral treatment history.

Contacts

Blair Baumwell, Media

public_affairs@gilead.com

Jacquie Ross, Investors

investor_relations@gilead.com

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