– Long-Term Data from the PURPOSE 1 and PURPOSE 2 Trials Demonstrate Continued High Efficacy, High Adherence and Consistent Safety Profile of Twice-Yearly Lenacapavir for PrEP –

– Detailed Phase 3 Results from the ISLEND-1 and ISLEND-2 Trials Highlight the Potential of Weekly HIV Treatment with Long-Acting Oral Islatravir/Lenacapavir –

– Global Access Momentum Continues for Twice-Yearly Lenacapavir for HIV Prevention, Including Discussions in Latin America –

FOSTER CITY, Calif.--(BUSINESS WIRE)-- Gilead Sciences, Inc. (Nasdaq: GILD) today announced its upcoming participation in the 26th International AIDS Conference (AIDS 2026) taking place in Rio de Janeiro, Brazil, from July 26-31. As a leader in HIV innovation, Gilead will share new scientific data from its HIV research and development programs and provide updates on its strategic initiatives and key collaborations. The data to be presented, together with Gilead-led symposia and community forums, reflect the company’s person-centered approach to advancing scientific discovery and the importance of partnership to help end the HIV epidemic.

“Progress against the HIV epidemic requires both scientific innovation and enduring partnerships with communities around the world,” said Jared Baeten, MD, PhD, Senior Vice President, Clinical Development, Virology Therapeutic Area Head, Gilead Sciences. “The data Gilead is presenting at AIDS 2026 reflect our ongoing commitment to advancing HIV prevention, treatment and cure research, with the goal of expanding meaningful choices that can help support the diverse needs, preferences and experiences of people and communities affected by HIV.”

Gilead’s AIDS 2026 program highlights include:

HIV Prevention

Featured as part of the AIDS 2026 press program are new long-term follow-up data from the 52-week open-label extension (OLE) phases of the Phase 3 PURPOSE 1 (NCT04994509) and PURPOSE 2 (NCT04925752) trials, evaluating twice-yearly lenacapavir for HIV prevention as pre-exposure prophylaxis (PrEP) across broad and geographically diverse populations. Following completion of the randomized blinded phases, participants in both studies had the option to receive lenacapavir in the OLE phase. More than 95% of eligible participants across the two trials elected to continue receiving lenacapavir or switch to lenacapavir from once-daily oral PrEP (either Truvada® [emtricitabine 200mg and tenofovir disoproxil fumarate 300mg; F/TDF] or Descovy® [emtricitabine 200mg and tenofovir alafenamide 25mg; F/TAF] in PURPOSE 1, or Truvada in PURPOSE 2).

More than 7,178 person-years of follow-up in PURPOSE 1 and 5,295 person-years in PURPOSE 2 demonstrated continued high efficacy among participants receiving lenacapavir. In PURPOSE 1, no new HIV infections were observed among participants during the OLE phase, including among participants who switched to lenacapavir from once-daily oral PrEP. In the PURPOSE 2 OLE phase, there was one HIV infection among participants who continued on lenacapavir, and no infections among participants who switched to lenacapavir from once-daily oral PrEP. Adherence to lenacapavir injections remained high, defined as participants receiving lenacapavir injections twice yearly as scheduled, with 96% of those in PURPOSE 1 and 92% in PURPOSE 2 continuing lenacapavir through 52 weeks.

The new long-term follow-up data also show that the safety profile of lenacapavir was consistent with prior findings from the randomized blinded phases of both studies, with no new safety signals identified and no differences in safety signals between participants continuing on lenacapavir and those who switched from once-daily oral PrEP to lenacapavir.

Additional Gilead HIV prevention data to be presented at AIDS 2026 will include qualitative insights into why participants in PURPOSE 1 and PURPOSE 2 chose lenacapavir in the trials’ OLE phases. Other data will explore options in lenacapavir administration, including alternative injection sites, and highlight survey results about PrEP awareness and potential opportunities to expand uptake across multiple countries.

HIV Treatment

For the first time, full results from the joint Gilead and Merck (NYSE: MRK) Phase 3 ISLEND trials evaluating a novel investigational long-acting oral single-tablet HIV treatment regimen will be presented in late-breaking oral sessions, and featured in the AIDS 2026 press program. The first potential once-weekly combination regimen pairs Merck’s islatravir, a next-generation nucleoside analog with multiple mechanisms of action, including reverse transcriptase translocation inhibition, with Gilead’s lenacapavir, a first-in-class capsid inhibitor that disrupts HIV at multiple stages of its lifecycle. The findings build on the positive topline results announced in June.

Additional data from Gilead’s HIV treatment program includes an oral presentation of five-year results from a study (NCT02881320) evaluating Biktarvy® (bictegravir 30 mg/emtricitabine 120 mg/tenofovir alafenamide 15 mg tablets, B/F/TAF) in pediatric populations. Two-year outcomes from the BICSTaR study (NCT03580668), evaluating the real-world effectiveness of once-daily Biktarvy® (bictegravir 50 mg/emtricitabine 200 mg/tenofovir alafenamide 25 mg tablets, B/F/TAF) in people living with HIV, will also be presented. The analysis includes treatment outcomes and patient-reported experiences among individuals with detectable viremia who switched to the single-tablet regimen.

HIV treatment pipeline research includes an oral presentation of Week 104 outcomes from a Phase 2 open-label study (NCT05729568) evaluating the investigational combination of lenacapavir in combination with broadly neutralizing antibodies (bNAbs) (teropavimab [GS-5423, TAB] and zinlirvimab [GS-2872, ZAB]). The first potential complete twice-yearly regimen is being evaluated in two Phase 3 trials: Daybreak 1 (NCT07682961) and Daybreak 2 (NCT07683000). Additional long-acting HIV treatment pipeline data presented at AIDS 2026 will characterize the resistance profile of GS-3242, an investigational integrase inhibitor being studied as a component of a potential twice-yearly injectable HIV treatment. GS-3242 in combination with lenacapavir is being evaluated in two phase 2 studies: Pulsar 1 (NCT07645287) and Pulsar 2 (NCT07708727).

HIV Cure

Gilead will also present updates from its HIV cure research program, reflecting the company’s continued commitment to advancing research across the HIV continuum and, ultimately, helping to end the HIV epidemic.

Gilead Symposia and Community Programming at AIDS 2026

In addition to its scientific presentations, Gilead will host two symposia focused on HIV prevention and treatment: Prevention Through Partnership: How Can We Collaborate to Help End New HIV Transmissions? and Living Fully with HIV: A Person-Centered Approach to Health and Well-Being. The sessions will bring together healthcare professionals, researchers, advocates and people affected by HIV to discuss the role of community partnerships, person-centered care and shared decision-making in advancing prevention, supporting long-term health and improving HIV care.

Gilead will also host a range of community-based programming, including the pre-conference Women Know What Works, which will focus on the issues specifically affecting women and girls in relation to HIV prevention, treatment and care.

Gilead’s Global Access Strategy for Twice-Yearly Lenacapavir for HIV Prevention

Gilead continues to make progress on its strategy to expand access to twice-yearly lenacapavir for HIV prevention as PrEP. The company recently expanded its partnership commitments with PEPFAR and the Global Fund, increasing the planned reach of its no-profit supply program by 50% – from 2 million people to up to 3 million people through 2028. Lenacapavir is now available in 10 priority countries across sub-Saharan Africa.

At the same time, licensed manufacturers, governments and implementation partners are actively preparing for upcoming generic availability, reflecting continued momentum toward making twice-yearly HIV prevention medicine, if approved, available to more people in the regions with the greatest unmet need.

Gilead is also engaged in ongoing discussions with the Pan American Health Organization (PAHO) to explore pathways to expand access in Latin America while advancing regulatory filings across the region.

Overview of Scientific Presentations

Key abstracts will include:

For more information about Gilead at AIDS 2026, including a complete list of abstracts and their corresponding oral and poster sessions, please visit: https://programme.aids2026.org/

Islatravir and lenacapavir in combination are investigational and not approved for use.

Teropavimab and zinlirvimab are investigational compounds. The use of these compounds in combination with lenacapavir are investigational, are not approved by any regulatory authority, and their safety and efficacy has not been established. The use of lenacapavir in virologically suppressed people with HIV is investigational and the safety and efficacy of this use have not been established.

GS-3242 is an investigational compound, and alone or in combination with lenacapavir, is not approved by any regulatory authority. Its safety and efficacy are unknown.

Please see below for U.S. Indications and Important Safety Information, including Boxed Warning, for Biktarvy and Yeztugo®.

There is currently no cure for HIV or AIDS.

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 approved classes of antiretroviral agents. While most antiretrovirals act on one stage of viral replication, lenacapavir is designed to inhibit HIV at multiple stages of its lifecycle and has no known exhibited cross-resistance 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 treatment and prevention research program. Lenacapavir is being developed as a foundation for potential future HIV therapies to offer both long-acting oral and injectable options with several dosing frequencies, in combination or as a mono agent, that help address the individual needs and preferences of people and communities affected by HIV.

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.

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 single-tablet regimen (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.

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. For patients weighing ≥14 kg to <25 kg, not recommended in patients with CrCl <30 mL/min.
• Hepatic impairment: Not recommended in patients with severe hepatic impairment.
• Prior to or when initiating: Test patients for HBV infection.
• Prior to or when initiating, and during treatment: As clinically appropriate, assess serum creatinine, CrCl, urine glucose, and urine protein in all patients. In patients with chronic kidney disease, assess serum phosphorus.

Pregnancy and lactation

• Pregnancy: BIKTARVY is recommended in pregnant individuals who are virologically suppressed on a stable ARV regimen with no known substitutions associated with resistance to any of the individual components of BIKTARVY. Lower plasma exposures of BIKTARVY were observed during pregnancy; therefore, viral load should be monitored closely during pregnancy. An Antiretroviral Pregnancy Registry (APR) has been established. Available data from the APR for BIC, FTC, or TAF show no difference in the rates of birth defects compared with a US reference population.
• Lactation: Individuals infected with HIV-1 should be informed of the potential risks of breastfeeding.

About Gilead HIV

For almost 40 years, Gilead has been a leading innovator in the field of HIV, driving advances in treatment, prevention and cure research. Gilead researchers have developed 13 HIV medications, including the first single-tablet regimen to treat HIV, the first antiretroviral for pre-exposure prophylaxis (PrEP) to help reduce new HIV infections, and the first long-acting injectable HIV prevention medication administered twice yearly. Our advances in medical research have helped to transform HIV into a treatable, preventable, chronic condition for millions of people.

Gilead is committed to continued scientific innovation to provide solutions for the evolving needs of people affected by HIV around the world. Through partnerships, collaborations and charitable giving, the company also aims to improve education, expand access and address barriers to care, with the goal of ending the HIV epidemic worldwide. Gilead has been repeatedly recognized as one of the top two leading philanthropic funders of HIV-related programs in a report released by Funders Concerned About AIDS.

Discover more about Gilead’s unique collaborations worldwide and the work to help end the HIV epidemic.

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. In 2025, Gilead announced a planned $32 billion investment to further strengthen its U.S. footprint to power the next era of discovery, job creation and public health preparedness – while continuing to invest globally to ensure patients everywhere benefit from its scientific innovation. Gilead operates in more than 35 countries worldwide, with headquarters in Foster City, Calif.

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 Gilead’s ability to initiate, progress or complete clinical trials or studies within currently anticipated timelines or at all, and the possibility of unfavorable results from ongoing and additional clinical trials or studies, including those involving Biktarvy, bictegravir, lenacapavir, teropavimab, zinlirvimab and GS-3242 (such as BICSTaR, Daybreak 1, Daybreak 2, ISLEND-1, ISLEND-2, Pulsar 1, Pulsar 2, PURPOSE 1 and PURPOSE 2); uncertainties relating to regulatory applications and related filing and approval timelines, including potential applications for programs and/or indications currently under evaluation, and the risk that any regulatory approvals, if granted, may be subject to significant limitations on use or subject to withdrawal or other adverse actions by the applicable regulatory authority; the possibility that Gilead may make a strategic decision to discontinue development of these programs and, as a result, these programs may never be successfully commercialized for the indications currently under evaluation; Gilead’s ability to effectively manage the access strategy relating to lenacapavir, subject to necessary regulatory approvals; Gilead’s ability to realize the anticipated benefits from the collaboration with PEPFAR and The Global Fund; difficulties or unanticipated expenses in connection with the collaboration; 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 March 31, 2026, 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 Biktarvy, Descovy, Truvada, and Yeztugo, including Boxed Warning, are available at www.gilead.com.

Biktarvy, Descovy, Truvada, Yeztugo, Gilead and the Gilead logo are 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 (@Gilead Sciences) and LinkedIn, or contact Gilead Public Affairs.

View source version on businesswire.com: https://www.businesswire.com/news/home/20260720642268/en/

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Jacquie Ross, Investors

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Source: Gilead Sciences, Inc.