Merck Launches Phase III Clinical Trial of Two-Dose 9vHPV Vaccine Regimen in Chinese Girls Aged 9–14

Recently, the official website of the Drug Clinical Trial Registration and Information Disclosure Platform showed that MSD registered a Phase III clinical trial for the nine-valent HPV vaccine (Gardasil 9). Specifically, this involves adding a two-dose immunization schedule (0, 6-12 months) for girls aged 9 to 14 in China. The vaccine aims to prevent cervical cancer, vulvar cancer, vaginal cancer, anal cancer, and related precancerous lesions, anal and genital lesions, abnormal cervical cytology results, and persistent infections caused by HPV types 6, 11, 16, 18, 31, 33, 45, 52, and 58.

This is a randomized, open-label, parallel-group Phase III clinical trial. Using a three-dose immunization schedule of the nine-valent HPV vaccine (V503) in Chinese women aged 20 to 26 as a control, the immunogenicity and safety of a two-dose immunization schedule of V503 are being evaluated in Chinese girls aged 9 to 14. The trial plans to recruit 1,500 females aged 9 to 26.

The primary objective of Phase I is: To demonstrate that the two-dose regimen (0, 6-12 months) of the nine-valent HPV vaccine induces non-inferior geometric mean titers (GMTs) of competitive Luminex immunoassay (cLIA) antibodies for each vaccine type in girls aged 9 to 14 years compared to the three-dose regimen (0, 2, 6 months) in females aged 20 to 26 years.

The Main Purpose of Phase II: To summarize the antibody persistence in girls aged 9 to 14 years following a two-dose immunization schedule with the 9vHPV vaccine, based on cLIA antibody GMTs and cLIA antibody seropositivity rates at months 12, 24, 36, 48, 60, and 72 after the final vaccine dose.

Gardasil 9 is a nine-valent HPV vaccine developed by Merck Sharp & Dohme AG (MSD). It has been approved by the FDA for the prevention of HPV-related diseases in individuals aged 9-45 (both males and females). In April 2018, the product entered the Chinese market for the vaccination of females aged 16-26. Since its launch, Gardasil 9 has been in short supply in China.

By the end of 2021 and early 2022, MSD registered two Phase III clinical trials for Gardasil 9 targeting Chinese males aged 9-45. It is expected that the applicable population will continue to expand, benefiting more people in China.