Gilead Sciences Inc.
Gilead Sciences (GILD)
Overview
Gilead Sciences is an American biopharmaceutical company headquartered in Foster City, California, that discovers, develops, and commercializes medicines in areas of significant unmet medical need. It is best known as the dominant player in HIV treatment and prevention, and it also markets therapies for viral hepatitis, COVID-19, oncology, and inflammatory disease. Gilead trades on the Nasdaq and is a component of the S&P 500 and Nasdaq-100. For fiscal year 2025 the company generated roughly $29.4 billion in revenue (trailing-twelve-month revenue near $30.5 billion as of mid-2026) and employed approximately 17,000 people worldwide, making it one of the larger pure-play biopharmaceutical companies in the S&P 500.
What They Do & How They Make Money
Gilead's business model is that of a research-driven, patent-protected pharmaceutical company: it invests heavily in R&D and business-development deals to discover or acquire promising drug candidates, runs them through clinical trials, and, once approved, sells them at premium prices protected by patents and regulatory exclusivity. The overwhelming majority of revenue comes from product sales of prescription medicines, sold mainly to wholesalers, specialty pharmacies, and government health programs (with significant volume tied to U.S. payers and international health systems). Because chronic diseases like HIV require lifelong daily therapy, Gilead's core HIV franchise produces highly recurring, subscription-like revenue as patients typically stay on treatment for years. The company supplements organic R&D with acquisitions and licensing deals — historically Pharmasset (hepatitis C, 2011) and Kite Pharma (CAR-T cell therapy, 2017), and more recently smaller bolt-on and platform deals such as Arcellx, Tubulis, and Ouro Medicines in 2026 — to build out newer growth areas like oncology and next-generation cell therapy. Profitability is driven by high gross margins typical of branded pharmaceuticals, offset by heavy R&D spending, acquisition-related charges (including large one-time in-process R&D write-offs when deals close), and increasing pricing and rebate pressure from payers.
Business Segments
Gilead reports its business as a single operating segment (biopharmaceuticals) but discloses revenue by major product/therapeutic category, which functions as its de facto segmentation:
- HIV — the largest and most profitable category by far, anchored by Biktarvy (the leading single-tablet HIV regimen) and Descovy (used for both treatment and PrEP prevention). In recent quarters HIV product sales have run near $5.5–5.7 billion per quarter and continue to grow at a double-digit pace, with Descovy in particular posting very strong growth.
- Liver Disease — hepatitis B, C, and D and related liver therapies (e.g., Vemlidy, Epclusa, and newer agents like Livdelzi), a smaller but still meaningful and steady contributor.
- Oncology — led by Trodelvy (an antibody-drug conjugate for breast and other cancers), a fast-growing but still comparatively small piece of revenue, growing at double-digit rates as the drug expands into new indications.
- Cell Therapy — Yescarta and Tecartus, CAR-T cell therapies for lymphoma and leukemia acquired via Kite Pharma; this segment has been more volatile, recently declining amid competitive and manufacturing dynamics, though Gilead is investing further here (e.g., the Arcellx collaboration/acquisition).
- Veklury (COVID-19) — the antiviral remdesivir; once a major pandemic-era revenue source, it has shrunk dramatically (down roughly 80%+ year over year in recent quarters) as COVID-19 hospitalizations have declined, and now represents a minor share of sales.
HIV alone typically accounts for well over half of total company revenue and an even larger share of profit, making it the single most important driver of Gilead's financial performance.
Competitors
- HIV: ViiV Healthcare (the HIV-focused joint venture majority-owned by GSK, with Pfizer and Shionogi as minority partners) is Gilead's primary rival, especially with long-acting injectable regimens (e.g., Cabenuva) that compete against Gilead's daily pills; Merck also competes in HIV.
- Hepatitis/Liver Disease: AbbVie (Mavyret) is the main competitor in hepatitis C, alongside generic and biosimilar pressure over time.
- Oncology: A broad set of large oncology players including AstraZeneca, Roche/Genentech, Merck, Bristol Myers Squibb, and Daiichi Sankyo compete across antibody-drug conjugates and other cancer therapeutics targeting overlapping tumor types.
- Cell Therapy: Bristol Myers Squibb (Breyanzi), Novartis (Kymriah), and Johnson & Johnson/Legend Biotech (Carvykti) are the main CAR-T and cell-therapy rivals, an increasingly crowded and technically demanding field.
- Broader industry: Large diversified pharmaceutical companies (Pfizer, Merck, AbbVie, Bristol Myers Squibb) and specialty biotechs compete for capital, talent, and licensing deals across all of Gilead's therapeutic areas.
Competitive Position
Gilead's core moat is its entrenched, decades-long leadership in HIV treatment and prevention, built on a deep patent portfolio, an efficient once-daily pill franchise, extensive real-world clinical data, and strong relationships with prescribers, payers, and patient-advocacy communities — all of which make it costly and slow for switching competitors to displace Biktarvy and Descovy. This franchise throws off substantial free cash flow that funds dividends, buybacks, and further R&D/M&A, giving Gilead financial flexibility that smaller biotech rivals lack. The company is using that cash flow to diversify beyond HIV into oncology and cell therapy, areas with higher long-term growth potential but also more competition and clinical/regulatory risk.
Key risks include the ongoing threat of long-acting injectable HIV therapies from ViiV and others, which could erode Gilead's daily-pill dominance over time (Gilead is countering with its own long-acting HIV assets in development); the eventual loss of patent exclusivity on Biktarvy later in the decade, which would expose the company to generic competition on its largest product; continued softness in Veklury as COVID-19 becomes endemic; execution risk in scaling cell therapy amid tough competition and manufacturing complexity; and the general risks facing all large pharma companies — U.S. drug-pricing and rebate reform, patent litigation, and clinical-trial setbacks in the pipeline. Recent large acquisitions (Arcellx, Tubulis, Ouro Medicines) generated significant one-time non-cash accounting charges (in-process R&D write-offs) that pushed the company to a reported net loss in 2026 even though underlying "base business" product sales continued to grow at a double-digit clip, illustrating how M&A-driven diversification can create near-term GAAP earnings volatility even as the operating business remains healthy.