Gilead to Present New Data on Treatment Response and Long-Term Management of Rare Liver Diseases at The Liver Meeting® 2026

Gilead Sciences, Inc. (Nasdaq: GILD) will present new clinical and real-world evidence across primary biliary cholangitis (PBC) and chronic hepatitis delta virus (HDV) infection at The Liver Meeting^® 2026, hosted by the American Association for the Study of Liver Diseases (AASLD), November 5-9 in Denver, Colorado. The data will examine durability of response, patient-relevant symptoms, and opportunities to better understand long-term disease management across these two rare and serious liver diseases.

Key Highlights

• Gilead’s scientific program includes 21 accepted abstracts, including late-breaking Phase 3 research from the Livdelzi^® (seladelpar) 10 mg development program and new long-term and real-world evidence for Hepcludex^® (bulevirtide-gmod) 2 mg and 8.5 mg in chronic HDV.

• The portfolio of research reflects Gilead’s continued focus on generating evidence that helps broaden understanding of treatment response, patient experience, and long-term management considerations.

• By combining long-term clinical data, real-world insights, and research in patient-centred outcomes, Gilead continues to drive innovation and progress scientific advancements to inform treatment decisions and enhance understanding of rare liver diseases.

Improving Care Across the PBC Journey

Gilead will present analyses from the Livdelzi clinical development program and real-world studies, including late-breaking Phase 3 presentation of the IDEAL study results which evaluate the impact of seladelpar on composite alkaline phosphatase (ALP) normalization in a historically understudied population of adults living with PBC with lower levels of ALP elevation (1-1.67x ULN) who were on or intolerant to ursodeoxycholic acid (UCDA). (LB#5007). ALP normalization is an increasingly recognized treatment goal that continues to be studied in relation to long-term outcomes in PBC. Additional data on safety and efficacy of seladelpar up to five years (#1170) and late-breaking data on fatigue (LB#5040) will also be presented.

Additional real-world studies will examine persistent gaps in care, including factors affecting eligibility for, and escalation to, second-line treatment (#1170 and #1221). Together, the analyses provide a broader understanding of the diverse experiences, unmet needs and challenges faced by people living with PBC, including those at high risk of disease progression.

“As treatment options evolve, our ambitions for people living with rare liver diseases should evolve as well,” said Swati Tole, Senior Vice President, Clinical Development, Inflammation at Gilead. “At The Liver Meeting, we will present late-breaking results from the Phase 3 IDEAL study highlighting composite alkaline phosphatase (ALP) normalization, an important marker of disease activity in people with PBC. We will also share data that look beyond biochemical measures of disease activity to explore durability of response, symptoms and the realities of long-term disease management. Together, these insights can help broaden our understanding of important aspects of care for people living with PBC.”

Advancing Long-Term Disease Outcomes in Chronic HDV

Gilead will also present new long-term and real-world data that deepens the understanding of Hepcludex for the treatment of chronic HDV. Highlights include 96-week efficacy findings on the combined virologic and biochemical response (#3203) and a 48-week analysis of clinically significant portal hypertension prevalence and impact of Hepcludex in people living with chronic HDV (#3243).

U.S. real-world studies will also spotlight low testing rates (#4080) and the burden of advanced liver disease (#3216), underscoring the need for earlier detection and stronger long-term management for people living with HDV.

Gilead’s Commitment to Improving Outcomes for People with Liver Diseases

For people living with PBC and HDV, delayed diagnosis and treatment can mean more time living with burdensome symptoms or progressive liver damage. Gilead’s new data highlight these persistent gaps and showcase opportunities for earlier diagnosis, timely treatment escalation, more patient-centered research, and a better understanding of long-term disease management. Collectively, the data emphasizes the importance of identifying people at risk of progression, optimizing treatment decisions and advancing understanding of long-term outcomes across PBC and HDV.

For more information, including a complete list of abstract titles being presented at the meeting, please visit the AASLD website.

Key Abstracts at AASLD 2026:

About Livdelzi

Livdelzi (seladelpar) is an oral PPAR‑delta agonist, or delpar, for the treatment of primary biliary cholangitis (PBC). PPAR‑delta is known to regulate key metabolic and liver disease pathways. Preclinical and clinical data indicate that Livdelzi has anticholestatic, anti‑inflammatory, antipruritic, and antifibrotic effects.

Clinical trial data demonstrate that Livdelzi supports meaningful improvements in key markers of disease activity, including biochemical response and alkaline phosphatase (ALP) normalization, with sustained effects observed over long‑term follow‑up in multiple studies. These findings are supported by clinical studies evaluating Livdelzi in participants treated for up to 5 years.

Livdelzi has the potential to help address ongoing unmet needs for people living with PBC, including those who remain inadequately controlled on existing therapies. Pruritus is one of the most common and debilitating symptoms of PBC that can significantly impair quality of life. Clinical trial data have demonstrated improvements in pruritus with Livdelzi compared with placebo.

U.S. Indication for Livdelzi

Livdelzi is indicated for the treatment of primary biliary cholangitis (PBC), in combination with ursodeoxycholic acid (UDCA) in adults who have had an inadequate response to UDCA, or as monotherapy in patients unable to tolerate UDCA. This indication is approved under accelerated approval based on a reduction of alkaline phosphatase (ALP). Improvement in survival or prevention of liver decompensation events have not been demonstrated. Continued approval for this indication may be contingent upon verification and description of clinical benefit in confirmatory trial(s).

Limitations of Use:

Use of Livdelzi is not recommended in patients who have or develop decompensated cirrhosis (e.g., ascites, variceal bleeding, hepatic encephalopathy).

U.S. Important Safety Information for LIVDELZI

Warnings and Precautions

• Fractures: Fractures occurred in 4% of LIVDELZI-treated patients compared to no placebo-treated patients. Consider the risk of fracture in the care of patients treated with LIVDELZI and monitor bone health according to current standards of care.

• Liver Test Abnormalities: LIVDELZI has been associated with dose-related increases in serum transaminase (AST and ALT) levels > 3 x ULN in patients receiving 50 mg and 200 mg once daily (5x and 20x higher than the recommended dosage of 10 mg once daily). Perform baseline clinical and laboratory testing when starting LIVDELZI and monitor thereafter according to routine patient management. Interrupt treatment if the liver tests (ALT, AST, total bilirubin, and/or ALP) worsen, or if the patient develops signs and symptoms of clinical hepatitis (e.g., jaundice, right upper quadrant pain, eosinophilia). Consider permanent discontinuation if liver tests worsen after restarting LIVDELZI.

• Biliary Obstruction: Avoid use of LIVDELZI in patients with complete biliary obstruction. If biliary obstruction is suspected, interrupt LIVDELZI and treat as clinically indicated.

Adverse Reactions

• The most common adverse reactions (≥5%) with LIVDELZI were headache (8%), abdominal pain (7%), nausea (6%), abdominal distension (6%), and dizziness (5%).

Drug Interactions

Potential Increased Exposure of LIVDELZI with:

• Probenecid: Avoid coadministration with LIVDELZI.

• Strong CYP2C9 Inhibitors: Monitor for adverse effects during concomitant use.

• Dual Moderate CYP2C9 and Moderate or Strong CYP3A4 Inhibitors (eg, fluconazole): Monitor for adverse effects during concomitant use.

• CYP2C9 Poor Metabolizers Using Moderate or Strong CYP3A4 Inhibitors: Monitor for adverse effects during concomitant use of a moderate or strong CYP3A4 inhibitor in patients who are CYP2C9 poor metabolizers.

• Dual or Multiple Clinical Inhibitors of Drug Transporters OATP1B1, OATP1B3, and BCRP (eg, cyclosporine): Monitor for adverse effects during concomitant use.

Potential Reduction in LIVDELZI Exposure with:

• Rifampin: Concomitant use of LIVDELZI with rifampin, an inducer of metabolizing enzymes, may result in delayed or suboptimal LIVDELZI biochemical response. Monitor biochemical response (eg, ALP and bilirubin) when patients initiate rifampin during LIVDELZI treatment.

• Bile Acid Sequestrants: Administer LIVDELZI at least 4 hours before or 4 hours after taking a bile acid sequestrant, or at as great an interval as possible.

Pregnancy and Lactation

• Pregnancy: There are insufficient data from human pregnancies exposed to LIVDELZI to allow an assessment of a drug-associated risk of major birth defects, miscarriage, or other adverse maternal or fetal outcomes. Report pregnancies to Gilead Sciences, Inc., at 1-800-445-3235.

• Lactation: There are no data on the presence of LIVDELZI in human milk, the effects on the breastfed infant, or the effects on milk production. The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for LIVDELZI and any potential adverse effects on the breastfed infant from LIVDELZI.

About Hepcludex (bulevirtide-gmod) 8.5 mg in the U.S.

Hepcludex (bulevirtide-gmod) is a first-in-class entry inhibitor for the treatment of adults living with chronic hepatitis delta virus (HDV) infection. Chronic HDV infection is a serious liver disease that occurs only as a co-infection in individuals with chronic HBV and is associated with rapid disease progression, liver failure, and increased mortality. Hepcludex is supplied as a vial for once-daily subcutaneous injection. Each vial contains an 8.5 mg dose when prepared according to the Instructions for Use within FDA-approved labeling.

Hepcludex works by blocking the entry of both HDV and HBV into liver cells, addressing a key step in the viral lifecycle. The FDA’s accelerated approval of Hepcludex is supported by data from the Phase 3 MYR301 study demonstrating that Hepcludex was an effective and generally well-tolerated treatment option, with efficacy and safety observed at week 48 through long-term treatment of up to 144 weeks.

Hepcludex is supplied as a once-daily injectable therapy and represents the first and only treatment option for people living with chronic HDV that received FDA accelerated approval in the United States, addressing a long-standing unmet medical need for this historically underserved patient community.

For more information, please visit Hepcludex.com

U.S. Access and Hepcludex Approval Across Markets

The Gilead Support Path^® Program offers information and resources to help patients diagnosed with chronic HBV, HDV and hepatitis C virus (HCV) and primary biliary cholangitis (PBC), as well as healthcare professionals, understand coverage and financial options for prescribed Gilead treatments.

Bulevirtide 2 mg is also approved for use in the European Economic Area (EEA), Canada the United Kingdom and other countries globally to treat people living with chronic HDV.

Please see below for U.S. Indication and Important Safety Information for Hepcludex.

U.S. Indication for Hepcludex

Hepcludex (bulevirtide-gmod) 8.5 mg for injection is indicated for the treatment of chronic hepatitis delta virus infection in adults without cirrhosis or with compensated cirrhosis.

This indication is approved under accelerated approval based on a decrease in HDV RNA and alanine aminotransferase (ALT) normalization. An improvement in disease-related clinical outcomes has not been established. Continued approval for this indication may be contingent upon verification and description of clinical benefit in a confirmatory trial(s).

U.S. Important Safety Information for HEPCLUDEX

IMPORTANT SAFETY INFORMATION

BOXED WARNING: POSTTREATMENT SEVERE ACUTE EXACERBATION OF HEPATITIS D and B

Severe acute exacerbations of hepatitis D and hepatitis B may occur after HEPCLUDEX is discontinued, especially in patients with cirrhosis, who may be at increased risk of more severe flares or progression to hepatic decompensation. Monitor hepatic function closely with both clinical and laboratory follow-up, including hepatitis B virus (HBV) DNA and hepatitis delta virus (HDV) RNA viral load, for at least six months in patients who discontinue HEPCLUDEX. Resumption of antiviral therapy may be warranted.

Warnings and Precautions

Hypersensitivity reactions including anaphylaxis: Hypersensitivity reactions, including anaphylaxis, have been reported with HEPCLUDEX. If signs or symptoms of a clinically significant hypersensitivity reaction or anaphylaxis occur, immediately discontinue HEPCLUDEX and initiate appropriate treatment.

Adverse Reactions

Most common adverse reactions (incidence ≥10%; all grades) in HEPCLUDEX clinical trials were injection site reactions, headache, abdominal pain, fatigue and pruritus.

Dosage and Administration

• Dosage in adults: 8.5 mg once daily administered by subcutaneous injection

• HEPCLUDEX should be continued as long as it is associated with a response to treatment. The optimal treatment duration is unknown.

• In all patients, manage the underlying HBV infection as clinically appropriate.

Pregnancy and Lactation

• Pregnancy: There are insufficient data from human pregnancies exposed to HEPCLUDEX to allow an assessment of a drug-associated risk of major birth defects, miscarriage, or other adverse maternal or fetal outcomes.

• Lactation: There are no data on the presence of HEPCLUDEX in human milk, the effects on the breastfed infant, or the effects on milk production. The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for HEPCLUDEX and any potential adverse effects on the breastfed child from HEPCLUDEX or from the underlying maternal condition.

About Gilead Sciences in Liver Disease

For decades, Gilead has pioneered the way forward to improve the lives of people living with liver disease around the world. We have helped to transform hepatitis C from a chronic condition into one that can be cured for millions of people. For individuals living with hepatitis B or D, Gilead’s focus on advancing medicines drives hope that today’s research will turn into tomorrow’s cures. Beyond viral hepatitis, Gilead is working to deliver advanced treatments for people living with PBC. But our commitment doesn’t stop there. Through ground-breaking science and collaborative partnerships, we strive to create healthier futures for everyone living with liver disease. Gilead remains committed to a future without liver disease.

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 $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 within currently anticipated timelines or at all, and the possibility of unfavorable results from ongoing or additional clinical trials, including those involving Livdelzi/Lyvdelzi (seladelpar) and Hepcludex (bulevirtide) (such as IDEAL); uncertainties relating to regulatory applications and related filing and approval timelines, including additional pending and potential applications for seladelpar and bulevirtide; 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; 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, 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.

Hepcludex, Livdelzi, Lyvdelzi, Gilead and the Gilead logo are trademarks of Gilead Sciences, Inc., or its related companies.

U.S. full Prescribing Information for Livdelzi^® and Hepcludex^® is available at www.gilead.com.

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)

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