Daniel O'Day

Daniel O'Day became Chairman and CEO of Gilead Sciences in 2019, recruited from Roche where he ran the pharmaceutical division. Gilead is best known for two revolutionary antiviral franchises: its HIV treatments (Biktarvy, Descovy — which together dominate the HIV treatment and prevention market) and its hepatitis C cures (Sovaldi, Harvoni — which actually cured HCV but thereby shrank their own market, the so-called "cure paradox"). O'Day's most consequential strategic decision was the $21 billion acquisition of Immunomedics in 2020, adding Trodelvy (sacituzumab govitecan) — an antibody-drug conjugate approved for metastatic triple-negative breast cancer and urothelial cancer. This acquisition marked Gilead's pivot into oncology, diversifying beyond its antiviral base. Trodelvy is being tested in additional cancer indications. The most exciting near-term catalyst is lenacapavir — a long-acting injectable HIV capsid inhibitor that requires injection only twice per year. Clinical trials showed lenacapavir achieved 100% efficacy in preventing HIV infection when administered as pre-exposure prophylaxis (PrEP), which could be transformational for global HIV prevention, particularly in Sub-Saharan Africa. Key stock drivers include Biktarvy sales trajectory, lenacapavir approval and uptake for PrEP and treatment, Trodelvy clinical trial results and label expansions, HIV competitive landscape (particularly long-acting injectables from ViiV/GSK), oncology pipeline progression, and the overall sustainability of HIV franchise growth versus generic erosion.