Strengthening HIV Market Dominance and Innovation of Once-Weekly Regimen

Gilead Sciences (GILD) leverages its flagship therapy Biktarvy, which generated $14.3 billion in annual revenue in 2025, to command more than 50% of the global HIV treatment market. However, growth based on a single once‑daily pill has reached its limits, and to overcome this, the company has focused on developing a once‑weekly oral regimen combining the capsid inhibitor Lenacapavir (Sunlenca) with Islatravir, a partnership with Merck. Recent top‑line results from the Phase 3 ISLEND‑1 and ISLEND‑2 trials announced on June 8, 2026 demonstrated non‑inferiority in viral suppression at week 48, dramatically improving dosing convenience. This reduces the psychological burden for patients who must take daily medication, enhances adherence, and offers substantial clinical value by improving long‑term survival.

Aggressive $11 billion M&A to Reshape Oncology Portfolio

To diversify a revenue stream heavily weighted toward HIV, Gilead invested roughly $11 billion in the first half of 2026 to acquire companies in oncology and immunology. It first acquired cell‑therapy specialist Arcellx for a total of $7.8 billion, securing exclusive rights to the multiple myeloma therapy Anitocabtagene autoleucel (Anito‑cel) and further strengthening Kite’s CAR‑T pipeline. Gilead also purchased German antibody‑drug conjugate (ADC) biotech Tubulis for $5 billion (including an upfront payment of $3.15 billion), adding the NaPi2b‑targeting ADC candidates such as TUB‑040 for ovarian and non‑small cell lung cancer to its pipeline. These strategic acquisitions are essential to rapidly restore growth momentum in the oncology segment after the clinical setback of Trodelvy (Sacituzumab govitecan).

Securing New Growth Engines in Autoimmune Disease and Cost‑Sharing Strategy

Beyond oncology, Gilead is cultivating autoimmune and inflammatory diseases as a third core growth pillar. In early 2026, it acquired Ouro Medicines for a total consideration of $2.175 billion (an upfront payment of $1.675 billion plus $500 million in milestones), gaining access to the BCMA×CD3 bispecific T‑cell engager Gamgertamig (OM336) for autoimmune indications. Notably, the deal features a cost‑sharing partnership with Galapagos, with each party bearing 50% of development expenses, thereby proactively mitigating large‑scale clinical cost risk. Following the 2024 approval of the primary biliary cholangitis therapy Livdelzi (Seladelpar), the addition of Gamgertamig is seen as a platform for Gilead to achieve early commercial success in immunology.

Risks of Pipeline Transition and Financial Challenges

For a company pursuing broad expansion, the scale of R&D spending and the success of late‑stage trial readouts will be the most critical test over the next two to three years. The cell‑therapy Anito‑cel faces a PDUFA date at the end of 2026, representing a pivotal moment for short‑term revenue diversification. Additionally, Biktarvy, Gilead’s HIV cash cow, could become subject to price negotiations under the U.S. Inflation Reduction Act (IRA), posing a risk that delayed commercialization of new assets could materially impair overall profitability. Consequently, Gilead must maximize the clinical success rates of its acquired candidates while executing R&D efficiently to preserve financial stability.