A Phase 3 interventional study of V503 and Placebo in Papillomavirus Infections, sponsored by Merck Sharp & Dohme LLC. Recruiting at 1 site in China. Open to female participants aged 10 Years to 45 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-10-22.
Sponsored by Merck Sharp & Dohme LLC (part of Merck & Co., Inc) · Phase 3, Interventional, and Prevention
Among 31 studies testing Human Papillomavirus Recombinant Vaccine nonavalent in Papillomavirus Infections — 10 open to participants now, 20 under way, 8 of them phase 3. Human Papillomavirus Recombinant Vaccine nonavalent · Papillomavirus Infections.
Among the 31 studies testing Human Papillomavirus Recombinant Vaccine nonavalent in Papillomavirus Infections, this one is the 15th largest by planned enrollment, is one of 4 that started in 2026, is one of 16 in phase 3, reaches primary completion later than 12 of the 19 other live ones, and was the 31st registered.
576 studies on the registry are indexed under Papillomavirus Infections; 132 are open to participants now.
Browse Papillomavirus Infections studies →10 of the 31 studies testing Human Papillomavirus Recombinant Vaccine nonavalent in Papillomavirus Infections are open now, in 9 countries. Recruiting first, the newest first:
Indiana University · Sites in Kenya
Ages 9–49 · Women only · Healthy volunteers
Western Institute for Veterans Research · Sites in United States
Ages 18+
Talia Sainz Costa · Sites in Spain
Ages 9–18 · Healthy volunteers
Louisiana State University Health Sciences Center in New Orleans · Sites in United States
Ages 18–65 · Healthy volunteers
Shanghai Bovax Biotechnology Co., Ltd. · Sites in China
Ages 9–45 · Women only · Healthy volunteers
By country, each count listing its studies:
Human Papillomavirus Recombinant Vaccine nonavalent: first FDA approval 2014 (Gardasil 9). What it is approved for, and how studies give it, is on its page →
Of the 85 Papillomavirus Infections studies recruiting now, 38 (45%) set no upper age limit and 42 (49%) stop at 75 or younger; 19 take children under 18; 36 take healthy volunteers.
This study: 10 Years to 45 Years · female · healthy volunteers too.
The full table on the hub →This tab as a report to print or save as PDF → With an account.
31 studies; the count open now beside each. This study's row is marked.
A study in two phases is counted once above. Listed by phase, each with its combined phases: Phase 2 4 · Phase 3 17 · Phase 4 10
First in 2009; this study’s year is marked. 4 started in 2026.
This study's planned enrollment of 930 is above the median of 235 across 402 interventional studies indexed under Papillomavirus Infections.
Median enrollment 700 across the 31 interventional studies. Of the 11 that completed or were terminated, 11 (100%) have results posted.
This tab as a report to print or save as PDF → With an account.
16 of 31 have an industry lead sponsor. The 10 most frequent:
This study is registered under Merck Sharp & Dohme LLC, one of the names counted as Merck & Co., Inc. Under that name alone:
Merck Sharp & Dohme LLC is the lead sponsor of 2,166 studies on the registry; 131 are open to participants now.
Of its 502 completed or terminated interventional studies of FDA-regulated products, 370 (74%) have results posted.
38 studies in Papillomavirus Infections by Merck & Co., Inc: 1 open now, 7 under way, 6 of them phase 3. Of 30 finished, 26 (87%) have results posted.
Among the 38 studies in Papillomavirus Infections by Merck & Co., Inc, this one is the 17th largest by planned enrollment of the 32 interventional ones that give a count, is the only one that started in 2026, is one of 26 in phase 3, and was the 38th registered.
Merck & Co., Inc’s Papillomavirus Infections studies by the year they started, since 2000.
3 of the studies testing Human Papillomavirus Recombinant Vaccine nonavalent in Papillomavirus Infections that are under way reach primary completion within a year, 1 of them phase 3. Phase 3 first, then by date:
| Study | Primary completion |
|---|---|
| NCT04199689Phase 3Merck Sharp & Dohme LLCEfficacy Against Oral Persistent Infection, Immunogenicity and Safety of the 9-valent Human Papillomavirus Vaccine (9vHPV) in Men Aged 20-45 Years (V503-049) | 2027-01-15 |
| NCT04206813Boston Medical CenterAn Exploratory Open-Label Clinical Trial Evaluating the Immunogenicity of the 9-valent 2-dose HPV Vaccination Regimen | 2026-12 |
| NCT07303751Institut d'Investigació Biomèdica de BellvitgeStudy Assessing Reduced HPV Infectivity and Transmission in HPV-Positive Women Following Vaccination With 9vHPV | 2027-02-01 |
Add all 3 to your calendar (.ics) → With an account.
Among the 31 studies testing Human Papillomavirus Recombinant Vaccine nonavalent in Papillomavirus Infections, from their registry updates:
Among Merck & Co., Inc’s 38 in Papillomavirus Infections:
This tab as a report to print or save as PDF → With an account.
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).
The goals of the trial are to learn:
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
The main inclusion criteria include but are not limited to the following:
Exclusion Criteria:
The main exclusion criteria include but are not limited to the following:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Biopsy and archival tissue
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Autoimmune disease
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants will receive V503 at Day 1, Month 2, and Month 6
Biological: V503
Participants will receive Placebo at Day 1, Month 2, and Month 6
Biological: Placebo
Participants will receive V503 at Day 1, Month 2, and Month 6
Biological: V503
Participants will receive Placebo at Day 1, Month 2, and Month 6
Biological: Placebo
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
Also known as: 9-valent HPV Vaccine, GARDASIL®9
Saline administered as a 0.5-mL IM injection on Day 1, Month 2, and Month 6
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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: Up to approximately Month 12
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.
Time frame: 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).
Time frame: 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.
Time frame: Up to approximately 1 month post vaccination (Up to approximately 7 months)
Plan to share: Yes — https://trialstransparency.msdclinicaltrials.com/pdf/ProcedureAccessClinicalTrialData.pdf
Data sharing details ↗ · externaldatasharing-msd.com
Started Oct 2026 (actual). Primary completion is estimated for Dec 2027, 14 months after the start.
Of 54 industry-sponsored phase 3 interventional studies under Papillomavirus Infections, half reached primary completion within 24 months of starting (the median), counting those still running; a quarter within 13 and three quarters within 64. This study's planned 14 months is below that.
Counting every sponsor, half of 60 studies reached it within 29 months; a quarter within 16 and three quarters within 67.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
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Studies of the drug tested here: Human Papillomavirus Recombinant Vaccine nonavalent