CI

At a glance

ClinicalIndex Comparison Record
Phase 3Completed· 1,059 enrolled / 1,059 target
Drug / intervention
V503 +1 morebiological
Likely dose
V503 20 mcgfrom record
Structured eligibility isn't available for this trial yet — see the full criteria in the Eligibility tab below.

Standardized by ClinicalIndex from the ClinicalTrials.gov record · verify against the source.

Search/NCT04635423
NCT04635423Phase 3CompletedOn Track (15.8/mo)Completion was 30mo ago
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A Phase 3, Randomized, Placebo-controlled Clinical Study to Evaluate the Efficacy, Immunogenicity and Safety of the 9vHPV Vaccine in Japanese Males, 16 to 26 Years of Age.

Merck Sharp & Dohme LLC·interventional·Posted Nov 19, 2020·Updated Jun 11, 2026

In Brief

A Phase 3 clinical trial evaluating V503 and Placebo for Warts, Genital and Neoplasms, Anal. Completed, enrolled 1,059 participants across 22 sites.

Detailed Summary

The purposes of this phase 3, double-blind, placebo-controlled clinical study are to evaluate the efficacy of V503 in preventing human papillomavirus (HPV)-related anogenital persistent infection, and to evaluate the safety/tolerability of V503, in Japanese males who are 16 to 26 years of age. It is hypothesized that administration of a 3-dose regimen of V503 reduces the combined incidence of HPV 6/11/16/18-related anogenital persistent infection, as well as the combined incidence of HPV 31/33/45/52/58-related anogenital persistent infection, compared with placebo. The study includes a Base Study to assess efficacy and safety of V503, and an Extension Study. Participants who received placebo in the Base Study will be eligible to receive V503 vaccine on Day 1, Month 2, and Month 6 of the Extension Study. Participants who received less than 3 doses of V503 in the Base Study will be offered the opportunity to complete the 3-dose regimen in the Extension Study.

Study Details

Study Typeinterventional
Allocation--
Masking--
Primary Purpose--
ConditionsWarts, Genital, Neoplasms, Anal
CountriesJapan
Collaborators--

Timeline

Phase 3CompletedFinished
202120222023202420252026
First PostedNov 19, 2020
Enrollment StartNov 30, 2020
Primary CompletionDec 31, 2023
Study CompletionJul 23, 2025
TodayJul 2, 2026
Enrollment to primary: 3.1 yearsPosted 5.6 years ago

Arms & Interventions

V503experimental

In the base study, participants receive an intramuscular (IM) injection of V503 at Day 1, Month 2, and Month 6.

Biological: V503
Placeboplacebo_comparator

In the base study, participants receive an IM injection of placebo at Day 1, Month 2, and Month 6.

Other: Placebo
V503 → Open Label V503 Extension Studyexperimental

Participants from V503 arm of the base study who do not complete the 3-dose series receive 1 or 2 doses of V503, on Day 1, or Day 1 and Month 4 of the open label extension study.

Biological: V503
Placebo → Open Label V503 Extension Studyexperimental

Participants from the placebo arm of the base study receive 3 doses of V503 on Day 1, Month 2 and Month 6 of the open label extension study.

Biological: V503

Interventions

V503biological

9-valent vaccine, HPV 6/11/16/18/31/33/45/52/58, L1 virus-like particle (VLP) 30/40/60/40/20/20/20/20/20 mcg per dose.

Placeboother

0.9% sodium chloride (NaCL)