Papillomavirus InfectionsPhase 3NCT07785843
A Clinical Study of V503 in Chinese Females Who Have Previously Received a Bivalent Human Papillomavirus (HPV) Vaccine (V503-108)
A Phase 3 study testing V503 in people with Papillomavirus Infections, run by Merck Sharp & Dohme LLC at 1 site in China.
Trial summary
Researchers want to learn if V503 (also called the 9-valent human papillomavirus [9vHPV] vaccine, recombinant) 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 (2vHPV) vaccine. Read more about this study
- Who is it for?
- Ages 10 to 45 years, women onlyHealthy volunteers can take part
- Conditions the study is for
- Papillomavirus Infections
- What is being tested?
- V503
- Type of treatment
- Vaccines, Injection or infusion
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 930 participants
- Where
- 1 siteChina
- Study dates
- 10 Oct 2026to 22 Dec 2028
- Phase
- Phase 3
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 10 to 45 years
- Women only
- Healthy volunteers accepted
- Child, Adult
Who may be able to join
- The main inclusion criteria include but are not limited to the following:
- For participants to be enrolled in prior 2vHPV (bivalent human papillomavirus [HPV] vaccine) vaccine groups: has received at least one dose of any one of the three currently marketed 2vHPV vaccines, with the last dose administered at least one year prior to Day 1.
- For participants to be enrolled in HPV vaccine naïve groups: has never received any HPV vaccine.
Who cannot join
- The main exclusion criteria include but are not limited to the following:
- Has known thrombocytopenia or any coagulation disorder that would contraindicate intramuscular injections.
- Has a history of abnormal Pap test showing low-grade squamous intraepithelial lesion (LSIL), high-grade squamous intraepithelial lesion (HSIL) or atypical squamous cells - undetermined significance (ASC-US), atypical squamous cells - cannot exclude HSIL (ASC-H), atypical glandular cells, or biopsy showing CIN, AIS, or cervical cancer.
- Has a history of external genital wart, vulvar intraepithelial neoplasia (VIN), vaginal intraepithelial neoplasia (VaIN), AIN, vulvar cancer, vaginal cancer, or anal cancer.
- Has a history of a positive test for HPV (including HPV types not in the vaccine).
- Is currently immunocompromised or has been diagnosed as having congenital or acquired immunodeficiency, human immunodeficiency virus (HIV) infection, lymphoma, leukemia, systemic lupus erythematosus (SLE), rheumatoid arthritis, juvenile rheumatoid arthritis (JRA), inflammatory bowel disease, or other autoimmune condition.
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- Has a history of splenectomy.
- Has received, is receiving, or plans to receive the following immunosuppressive therapies: radiation therapy, cyclophosphamide, azathioprine, methotrexate, any chemotherapy, cyclosporin, leflunomide (Arava™), tumor necrosis factor alpha (TNF-α) antagonists, monoclonal antibody therapies (including rituximab [Rituxan™]), intravenous gamma globulin (IVIG), antilymphocyte sera, or other therapy known to interfere with the immune response. With regard to systemic corticosteroids, a participant will be excluded if the participant is currently receiving steroid therapy, has recently (defined as within 2 weeks of enrollment) received such therapy, or has received 2 or more courses of corticosteroids (orally or parenterally) lasting at least 1 week within 12 months prior to enrollment. Participants using inhaled, nasal, or topical corticosteroids are considered eligible for the study.
- Has received, is receiving, or plans to receive any immune globulin product (including RhoGAM™ [Ortho-Clinical Diagnostics]) or blood derived product other than IVIG.
- Has participated in an HPV vaccine clinical trial and has received either active agent or placebo.
- Has received any marketed HPV vaccine other than the 2vHPV vaccines.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
China1 site, 1 recruiting
- Recruiting
Yuhuan Center for Disease Control and Prevention ( Site 0001)
Taizhou, Zhejiang, 317600
Study Coordinator, +86057687216253
About this study
Official title: A Phase 3 Randomized, Placebo-Controlled, Double-Blind Study to Evaluate the Immunogenicity and Safety of V503 in Chinese Females Aged 10 to 45 Years Who Have Previously Received a Bivalent Human Papillomavirus (HPV) Vaccine
Researchers want to learn if V503 (also called the 9-valent human papillomavirus [9vHPV] vaccine, recombinant) 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 (2vHPV) vaccine.
The 9vHPV vaccine protects against diseases caused by 9 types of HPV (6, 11, 16, 18, 31, 33, 45, 52, and 58) and the 2vHPV vaccine protects against diseases caused by 2 types of HPV (16 and 18).
Read more
The goals of the trial are to learn:
- If the 9vHPV vaccine can induce an immune response to HPV types 6, 11, 16, 18, 31, 33, 45, 52, and 58 in participants who received the 2vHPV vaccine
- About the safety of the 9vHPV vaccine in prior 2vHPV vaccine recipients
- Conditions
- Papillomavirus Infections
- Being tested
- V503, Placebo
- Medical subject headings
- Papillomavirus Infections
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
V503Biological
Also called 9-valent HPV Vaccine, GARDASIL®9
V503 (9-vHPV vaccine [Types 6, 11, 16, 18, 31, 33, 45, 52, and 58]) administered as a 0.5-mL intramuscular (IM) injection on Day 1, Month 2, and Month 6
PlaceboBiological
Saline administered as a 0.5-mL IM injection on Day 1, Month 2, and Month 6
| Study group | Role | What they receive |
|---|---|---|
| Prior 2vHPV Vaccine Recipients Receiving V503 | Experimental | Participants will receive V503 at Day 1, Month 2, and Month 6 Receives: Biological: V503 |
| Prior 2vHPV Vaccine Recipients Receiving Placebo | Placebo comparator | Participants will receive Placebo at Day 1, Month 2, and Month 6 Receives: Biological: Placebo |
| HPV Vaccine-Naïve Participants Receiving V503 | Experimental | Participants will receive V503 at Day 1, Month 2, and Month 6 Receives: Biological: V503 |
| HPV Vaccine-Naïve Participants Receiving Placebo | Placebo comparator | Participants will receive Placebo at Day 1, Month 2, and Month 6 Receives: Biological: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Percentage of Participants Who Are Seropositive by Competitive Luminex Immunoassay (cLIA) to HPV Types 6, 11, 31, 33, 45, 52, and 58 (Month 7)
The percentage of participants who are seropositive for HPV types 6, 11, 31, 33, 45, 52, and 58 in the Prior 2vHPV Vaccine Recipients Receiving V503 group will be determined using cLIA. Seropositivity is defined as having a titer at or above the prespecified seropositivity cutoff for a given HPV type.
Measured: Up to approximately 1 month post vaccination 3 (Up to approximately Month 7)
Percentage of Participants Who Experience at Least 1 Solicited Injection-site Adverse Event (AE)
An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of a study intervention. AEs such as redness/erythema, swelling, pain, and induration at the injection site are recorded. The percentage of participants who experience 1 or more injection-site AE will be reported.
Measured: Up to approximately Day 8 post any vaccination
Percentage of Participants Who Experience at Least 1 Solicited Systemic AE
An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of a study intervention. Systemic AEs are those not categorized as injection-site AEs. The percentage of participants who experience 1 or more systemic AE will be reported.
Measured: Up to approximately Day 8 post any vaccination
Percentage of Participants Who Experience at Least 1 Serious AE (SAE)
An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of a study intervention. An SAE is an AE that results in death, is life threatening, results in a persistent or significant disability or incapacity, results in or prolongs an existing hospitalization, is a congenital anomaly or birth defect, or is another important medical event. The percentage of participants who experience 1 or more SAEs will be reported.
Measured: Up to approximately Month 12
Secondary outcomes (3)
Percentage of Participants Who Are Seropositive by cLIA to HPV Types 6, 11, 16, 18, 31, 33, 45, 52, and 58
The percentage of participants who are seropositive for HPV types 6, 11, 16, 18, 31, 33, 45, 52, and 58 will be determined using cLIA. Seropositivity is defined as having a titer at or above the prespecified seropositivity cutoff for a given HPV type.
Measured: Up to approximately 1 month post vaccination (Up to approximately 7 months)
cLIA Geometric Mean Titers (GMTs) for HPV Types 6, 11, 16, 18, 31, 33, 45, 52, and 58
Antibodies to HPV types 6, 11, 16, 18, 31, 33, 45, 52, and 58 will be measured using a cLIA. Antibody titers will be expressed as milli Merck Units/milliliter (mMU/mL).
Measured: Up to approximately 1 month post vaccination (Up to approximately 7 months)
Difference in Percentage of Participants Who Are Seropositive by cLIA to HPV Types 6, 11, 16, 18, 31, 33, 45, 52, and 58 Between Prior 2vHPV Vaccine Recipients and HPV Vaccine-Naïve Participants
The percentage of participants who are seropositive for HPV types 6, 11, 16, 18, 31, 33, 45, 52, and 58 will be determined using cLIA. Seropositivity is defined as having a titer at or above the prespecified seropositivity cutoff for a given HPV type. The difference in seropositivity percentages between participants who previously received a 2vHPV vaccine and subsequently receive V503 and participants who were HPV vaccine-naïve and receive V503 will be evaluated.
Measured: Up to approximately 1 month post vaccination (Up to approximately 7 months)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 Aug 2026
- Study start10 Oct 2026
- Primary completion18 Dec 2027 (estimated)
- Study completion22 Dec 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Papillomavirus InfectionsStudies of the same condition, open and under way.
- More trials run by Merck Sharp & Dohme LLCThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 3
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 930 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Merck Sharp & Dohme LLC
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Medical Director, Study director, Merck Sharp & Dohme LLC
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07785843
- Sponsor's protocol ID
- V503-108
- Status last verified
- Oct 2026
- First submitted
- 21 Aug 2026
- Last updated
- 22 Oct 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: https://trialstransparency.msdclinicaltrials.com/pdf/ProcedureAccessClinicalTrialData.pdf