Overview

Gilead Sciences is an American biopharmaceutical company headquartered in Foster City, California. Founded in 1987 by physician and investor Michael L. Riordan, the company began as Oligogen, a name reflecting its early interest in oligonucleotides and antisense approaches to targeting genetic sequences. It later adopted the Gilead Sciences name and concentrated increasingly on small-molecule antiviral medicines. That decision shaped the company’s identity and ultimately made it one of the most influential specialist pharmaceutical companies in HIV, hepatitis, and infectious disease. Gilead’s early development work included nucleotide analogues licensed from European academic institutions. These compounds led to medicines such as cidofovir, tenofovir, and adefovir, marketed respectively as Vistide, Viread, and Hepsera. The company went public on NASDAQ in 1992. Its acquisition of NeXstar Pharmaceuticals in 1999 added commercial infrastructure, AmBisome, and DaunoXome, while also giving Gilead a larger international sales organization. Gilead’s discovery of oseltamivir and its licensing arrangement with Roche produced Tamiflu, which became an important influenza medicine and generated substantial demand during avian-influenza and pandemic-preparedness periods. During the 2000s, Gilead developed from a venture-backed biotechnology start-up into a vertically broader pharmaceutical business. Viread, Emtriva, and combination products helped establish a major HIV franchise. In 2002 the company refocused its corporate strategy on antiviral medicines and sold certain cancer assets, but later returned to oncology and other therapeutic areas through acquisitions and internal research. Acquisitions of Triangle Pharmaceuticals, Corus Pharma, Myogen, CV Therapeutics, and other companies expanded its positions in HIV, respiratory disease, pulmonary hypertension, cardiovascular medicine, and research chemistry. The acquisition of Pharmasset in 2011 was a decisive turning point. It brought sofosbuvir into Gilead’s portfolio, leading to Sovaldi and Harvoni, direct-acting antiviral medicines that transformed treatment of hepatitis C and achieved very high cure rates in many patients. Their launch also generated intense public and political criticism over United States pricing, access, and the gap between list prices and manufacturing costs. Gilead subsequently broadened its portfolio through acquisitions and partnerships in oncology, inflammation, liver disease, and cell therapy. The 2017 purchase of Kite Pharma marked Gilead’s major entry into cellular immunotherapy. Kite’s Yescarta became one of the first commercially available CAR-T therapies in the United States for certain blood cancers. Gilead has since combined its antiviral base with oncology and cell-therapy research, including medicines and programs associated with Kite and Immunomedics. Its portfolio includes HIV treatments and prevention products such as Biktarvy and Truvada, hepatitis therapies, oncology products, cell therapies, and treatments for selected inflammatory, pulmonary, and liver disorders. During the COVID-19 pandemic, remdesivir, marketed as Veklury, became a prominent Gilead product after regulatory authorization for specified hospitalized patients. Gilead operates through research, clinical development, regulatory, manufacturing, licensing, and commercial activities. It continues to rely in part on external manufacturing partners while maintaining internal scientific, development, and commercial capabilities. The company’s stated public-health priorities include HIV prevention and treatment, viral hepatitis elimination, oncology, cell therapy, and addressing diseases with substantial unmet medical need. Its record combines major therapeutic breakthroughs with continuing debate about drug pricing, patent rights, access programs, and corporate responsibility.

History

Gilead Sciences was established in 1987 in Foster City, California, by Michael L. Riordan. Its early research centered on antiviral chemistry and nucleotide-based medicines. The company’s first major commercial products included Vistide, approved in 1996 for cytomegalovirus retinitis in certain patients with AIDS, and the influenza medicine Tamiflu, which Gilead discovered and later licensed to Roche for development and commercialization. Gilead’s 1992 initial public offering provided capital for research and development. In 1999, it acquired NeXstar Pharmaceuticals, gaining products including AmBisome and DaunoXome as well as a broader international commercial infrastructure. During the early 2000s, Gilead narrowed its strategic emphasis toward antivirals and sold its cancer assets to OSI Pharmaceuticals. It acquired Triangle Pharmaceuticals in 2002, obtaining emtricitabine, an important component of subsequent HIV combination products. The HIV franchise became the company’s central growth engine. Gilead developed or commercialized combinations containing tenofovir and emtricitabine, including Truvada and later single-tablet regimens. Products such as Atripla, Complera, Stribild and Genvoya simplified treatment for many patients. In 2012, Truvada received U.S. approval for HIV pre-exposure prophylaxis, creating a second major use and making the product important in public-health prevention programs. Descovy was subsequently approved for treatment and, in 2019, for PrEP in specified populations. Gilead entered a transformative phase in hepatitis C with the acquisition of Pharmasset in 2012. Sovaldi, followed by Harvoni and Epclusa, helped establish short-course, all-oral hepatitis C treatment as a new standard for many patients. The clinical impact was substantial, but high list prices led to disputes involving governments, insurers, patient advocates and public-health organizations. Gilead responded through access programs, licensing arrangements and commercial changes, while competition and generic entry later altered the market. The company expanded its scientific and commercial base through acquisitions and partnerships. The 2017 acquisition of Kite Pharma brought Yescarta, a CAR-T therapy, into Gilead and made cell therapy a core strategic area. Gilead also developed remdesivir, marketed as Veklury, which received emergency and later regulatory authorizations for eligible patients with COVID-19. In 2020, Gilead acquired Immunomedics for approximately $21 billion, adding Trodelvy and accelerating its move into oncology. In the 2020s, Gilead’s portfolio combined a mature but durable HIV business with oncology, cell therapy and immunology research. The company continued marketing medicines such as Biktarvy, Descovy, Yescarta, Tecartus, Trodelvy and Veklury while investing in clinical-stage programs and external collaborations. Its history illustrates the evolution of a specialist antiviral biotechnology company into a diversified global biopharmaceutical business.

2020
Immunomedics acquisition completed
[3]Gilead Sciences completes acquisition of Immunomedicsgilead.com
Gilead completed the acquisition of Immunomedics and added Trodelvy to its oncology portfolio.
2017
Kite acquisition
[1]Gilead Sciencesen.wikipedia.org
Gilead acquired Kite Pharma and entered commercial CAR-T cell therapy through Yescarta.
2012
Truvada approved for PrEP
[4]Gilead launches PrEP awareness advertisingnbcnews.com
The U.S. FDA approved Truvada to reduce the risk of sexually acquired HIV infection in eligible individuals.
2012
Pharmasset acquisition
[1]Gilead Sciencesen.wikipedia.org
Gilead acquired Pharmasset, obtaining the hepatitis C program that led to Sovaldi and related therapies.
2002
Antiviral strategy sharpened
[1]Gilead Sciencesen.wikipedia.org
Gilead adopted an exclusive antiviral focus and sold its cancer assets to OSI Pharmaceuticals.
1999
NeXstar acquisition
[1]Gilead Sciencesen.wikipedia.org
The acquisition expanded Gilead’s product portfolio and international commercial capabilities.
1996
Vistide launch
[1]Gilead Sciencesen.wikipedia.org
Vistide was launched for cytomegalovirus retinitis in certain patients with AIDS.
1992
Initial public offering
[1]Gilead Sciencesen.wikipedia.org
Gilead began trading publicly on Nasdaq.
1987
Company founded
[1]Gilead Sciencesen.wikipedia.org
Michael L. Riordan founded Gilead Sciences in California to develop antiviral medicines.

Products and positioning

A research-driven global biopharmaceutical company with historic leadership in HIV and hepatitis therapeutics and an expanding oncology and cell-therapy platform.

HIV treatment · 2018
Biktarvy
Biktarvy is a once-daily single-tablet HIV treatment combining bictegravir, emtricitabine and tenofovir alafenamide. Gilead has marketed it as a modern treatment option and used patient-centered campaigns emphasizing that people living with HIV can continue pursuing ordinary relationships, work and personal goals.
HIV treatment and prevention · 2016
Descovy
Descovy combines emtricitabine and tenofovir alafenamide. It is used for HIV treatment in combination with other antiretroviral agents and was later approved for PrEP in specified populations. Its prevention marketing positioned it as a newer option from the makers of Truvada.
HIV treatment and PrEP · 2004
Truvada
Truvada combines emtricitabine and tenofovir disoproxil fumarate. It became a foundational Gilead HIV product and, after its 2012 PrEP approval, one of the best-known medicines for preventing sexual transmission of HIV in eligible people.
Hepatitis C treatment · 2014
Harvoni
Harvoni is an oral fixed-dose combination of ledipasvir and sofosbuvir for hepatitis C. Gilead promoted it through campaigns focused on patients seeking treatment and the possibility of cure after years of living with infection.
Hepatitis C treatment · 2016
Epclusa
Epclusa combines sofosbuvir and velpatasvir and was designed to treat chronic hepatitis C across genotypes. Gilead’s Your Kind of Cure campaign highlighted the medicine’s broad genotype coverage and different patient circumstances.
CAR-T cell therapy · 2017
Yescarta
Yescarta is an autologous CAR-T cell therapy developed through Gilead’s Kite subsidiary. It reprograms a patient’s T cells to recognize certain blood-cancer targets and represents Gilead’s major commercial entry into cellular immunotherapy.
Oncology antibody-drug conjugate · 2020
Trodelvy
Trodelvy is an antibody-drug conjugate added through the Immunomedics acquisition. It delivers a cytotoxic payload to cells expressing Trop-2 and became a central asset in Gilead’s effort to build a broader oncology business.
COVID-19 antiviral · 2020
Veklury
Veklury is the commercial name for remdesivir, an intravenous antiviral used for eligible patients with COVID-19 under applicable regulatory guidance. It became Gilead’s most prominent respiratory-virus product during the COVID-19 pandemic.

Controversies

2022
Dispute over 340B contract-pharmacy restrictions
AIDS Healthcare Foundation publicly accused Gilead of unlawfully restricting access to certain medicines through 340B contract pharmacies and used the term “Greediad” in advocacy advertising. The supplied source documents the organization’s allegations and campaign, not a final legal determination.
Source
2021
Patients sue Gilead over alleged toxicity and disclosure of HIV drug risks
Patients with HIV brought a civil suit against Gilead, accusing the company of failing to properly report potential health effects of its HIV drugs and alleging that the drugs caused kidney and bone problems. The claims are allegations by the plaintiffs, not a court determination.
Source
2020
Gilead responds to questions about remdesivir trials and patents
Gilead issued a statement addressing questions about remdesivir, saying it had reached an agreement with Chinese health authorities to support two clinical trials and that it holds patents for the drug in China, the United States and elsewhere. It also said the China patent application for coronavirus use was pending approval.
Source
2019
U.S. government sues Gilead over PrEP patent rights
In a legal dispute involving Gilead Sciences, the U.S. Department of Health and Human Services filed a lawsuit concerning patent rights to Truvada and Descovy for HIV prevention. The suit asserts that the government owns the relevant PrEP patents. These claims are allegations made in the litigation and do not constitute a court determination. The event concerns a patent dispute over HIV prevention drugs and the asserted ownership of PrEP-related patents.
Source

Marketing campaigns

2023HIV is not a crime
United States
Gilead sponsored an advocacy advertisement with the Elizabeth Taylor AIDS Foundation addressing laws that criminalize aspects of living with HIV.
Outcome. The campaign connected Gilead’s public-health identity with legal and social advocacy surrounding HIV stigma.
Source
2020Step up, PrEP up
United States
Gilead introduced Descovy for PrEP through a television campaign that linked the product to the public recognition of Truvada while encouraging discussion of HIV risk and prevention choices.
Outcome. The campaign supported the transition of Gilead’s prevention marketing toward Descovy as Truvada approached generic competition.
Source
2019Keep Being You
United States
Gilead’s first major national television campaign for Biktarvy featured diverse actors and encouraged people living with HIV to continue living according to their identities and ambitions.
Outcome. The campaign differentiated Biktarvy through representation and an affirmative quality-of-life message.
Source
2018Truvada PrEP awareness campaign
United States
Gilead used television and digital advertising to increase awareness that Truvada could be taken daily as HIV pre-exposure prophylaxis.
Outcome. It marked a significant expansion of Gilead’s direct-to-consumer communication around HIV prevention.
Source
2017Let Go
United States
A successor Harvoni campaign used images of people releasing lanterns and a message about letting go of uncertainty after hepatitis C treatment.
Outcome. The creative shifted the message from readiness to the emotional relief associated with being cured.
Source
2015I Am Ready
United States
Gilead’s first branded television campaign for a specific hepatitis C medicine promoted Harvoni through stories of people ready to seek treatment and pursue a cure.
Outcome. The campaign broadened Gilead’s direct-to-consumer presence in hepatitis C after earlier disease-awareness work.
Source

Brand decisions

2020
Acquire ImmunomedicsM&A
Background
Gilead was seeking additional oncology assets to complement Kite and reduce reliance on its antiviral franchises.
Action taken
Gilead completed the acquisition of Immunomedics and obtained Trodelvy.
Aftermath
The transaction accelerated Gilead’s expansion into antibody-drug conjugates and solid-tumor oncology.
aggregate acquisition consideration. approximately $21 billion (2020)
Source
2017
Acquire Kite PharmaM&A
Background
Gilead sought to diversify beyond antiviral medicines and obtain a platform in engineered immune-cell therapies.
Action taken
Gilead acquired Kite Pharma and its CAR-T development and manufacturing capabilities.
Aftermath
Yescarta became a commercial foundation for Gilead’s cell-therapy and oncology strategy.
Source
2012
Acquire PharmassetM&A
Background
Pharmasset owned promising nucleotide-based hepatitis C research programs, including the compound that became sofosbuvir.
Action taken
Gilead acquired Pharmasset and integrated its hepatitis C research into Gilead’s development organization.
Aftermath
The transaction produced Sovaldi, Harvoni and later Epclusa, transforming Gilead’s position in hepatitis C.
Source
2002
Concentrate on antiviral medicinesStrategy
Background
Gilead had pursued both antiviral and cancer research during its early development.
Action taken
The company adopted an exclusive antiviral strategy and sold its cancer assets to OSI Pharmaceuticals.
Aftermath
The decision reinforced Gilead’s specialization in HIV, hepatitis and other viral diseases for much of the following decade.
Source

Recent events

2026.10.23
Reported2026.10.23
Gilead announces acquisition of PepStar oral inflammation drug program[17]吉利德宣布收购 PepStar 口服炎症药物项目finance.jrj.com.cn
Gilead said it would acquire PepStar Therapeutics’ oral inflammation drug program for a $1.275 billion cash upfront payment. The program includes an experimental treatment for intestinal disease.
2021.12.22
Reported2021.12.23
Royalty Pharma sues Gilead over royalties[13]U.S. government sues Gilead over PrEP patent rightslawstreetmedia.com
Royalty Pharma Collection Trust sued Gilead Sciences over alleged failure to pay royalties for use of a patent covering emtricitabine. The plaintiffs allege that Gilead used the patented treatment in more than ten drug combinations and breached a royalty-payment contract; these are allegations, not findings stated in the source.
2021.06.04
Reported2021.06.08
Patients sue Gilead over alleged toxicity and disclosure of HIV drug risks[16]Patients sue Gilead over alleged toxicity and disclosure of HIV drug riskslawstreetmedia.com
Patients with HIV brought a civil suit against Gilead, accusing the company of failing to properly report potential health effects of its HIV drugs and alleging that the drugs caused kidney and bone problems. The claims are allegations by the plaintiffs, not a court determination.
2021.04.27
Reported2021.04.27
Gilead supports expanded local remdesivir production in India[18]Gilead 支持扩大印度本地瑞德西韦生产thepharmaletter.com
Gilead said it was providing its voluntary licensing partners with technical assistance, support for adding local manufacturing facilities, and donated active pharmaceutical ingredient to scale up remdesivir production in India.
2021.04
Reported2021.05.04
Gilead sues Russia over remdesivir compulsory license[14]U.S. government sues Gilead over PrEP patent rightsstatnews.com
Gilead Sciences filed a lawsuit against the Russian government over its authorization for a domestic company to manufacture and market remdesivir, also known as Veklury. The article says the government had issued a compulsory license to Pharmasyntez.
2021.03.26
Reported2021.03.26
Gilead Sciences announces Bill Lee's retirement[19]吉利德科学宣布比尔·李退休investingnews.com
Gilead Sciences announced that Bill Lee, PhD, was retiring from the company after three decades. The source does not state the retirement date.
2021.03.26
Reported2021.03.26
Gilead Sciences announces Flavius Martin as research executive vice president[19]吉利德科学宣布比尔·李退休investingnews.com
Gilead Sciences announced that Flavius Martin would join the company as executive vice president of research and join its senior leadership team, assuming responsibility for the research organization effective April 12, 2021.
2021.03.04
Reported2021.03.04
Gilead completes acquisition of MYR GmbH[20]吉利德完成对MYR GmbH的收购investingnews.com
Gilead Sciences announced completion of its acquisition of MYR GmbH for up to approximately €1.45 billion in aggregate cash consideration. MYR became a wholly owned subsidiary of Gilead.
2020.12.11
Reported2020.12.11
Gilead announces acquisition of MYR[21]吉利德宣布收购MYRfinance.sina.com.cn
Gilead announced an all-cash deal to acquire German biopharmaceutical company MYR for 1.15 billion euros. The transaction was expected to close in the first quarter of the following year; completion had not yet occurred in the report.
2020.12.09
Reported2020.12.09
Gilead launches Racial Equity Community Impact Fund[22]吉利德推出种族平等社区影响基金investingnews.com
Gilead announced the launch of a fund that will initially provide $10 million in grants to 20 organizations over three years to support organizations working to address racial inequities affecting Black communities in the United States.