Merck registers Phase 3 V503 HPV vaccine trial in Chinese females previously given 2vHPV shot

Merck Sharp & Dohme's newest registry posting is a Phase 3 HPV vaccine study, alongside updates to two previously listed oncology and infectious disease trials.

• Merck registered a Phase 3 trial of V503, also known as GARDASIL®9, testing whether the 9-valent HPV vaccine can induce an immune response to HPV types 6, 11, 16, 18, 31, 33, 45, 52, and 58 in Chinese females who previously received the bivalent HPV vaccine¹. The study is listed as recruiting, with Chinese females aged 10 to 45 years¹ enrolled and estimated enrollment of 930 participants; primary completion is estimated for 2027-12-18.
• The Phase 2 trial combining MK-2010, a trial treatment designed to help the immune system fight cancer², with sacituzumab tirumotecan in advanced solid tumors remains recruiting, with estimated enrollment of 200 participants; the record was last updated 2026-10-15.
• The Phase 1 crossover study of MK-4646, a trial medicine designed to treat HIV-1³, evaluating its effect on rosuvastatin pharmacokinetics remains not yet recruiting, with an estimated enrollment of 16 participants at a single site in South Miami, Florida; the record was last updated 2026-10-05.