For Healthcare Professionals

Efficacy, Immunogenicity and Safety of V503 in Chinese Women Aged 20-45 Years (V503-023)


About the study

This study will evaluate the efficacy, immunogenicity and safety of 9-valent human papillomavirus (9vHPV; V503) vaccine in Chinese women 20 to 45 years of age. The primary hypotheses are: 9vHPV vaccine reduces the incidence of HPV 31-, 33-, 45-, 52-, and 58-related 12-month persistent infection at least 1 month post Dose 3, compared with quadrivalent HPV (qHPV) vaccine in women 20 to 45 years of age who are seronegative at Day 1 and polymerase chain reaction (PCR) negative Day 1 through Month 7 to the relevant HPV type; and 9vHPV vaccine induces non-inferior competitive luminex immunoassay (cLIA) geometric mean titers (GMTs) for each of HPV 6, 11, 16, and 18 one month post Dose 3, compared with qHPV vaccine in women 20 to 45 years of age who are seronegative at Day 1 and PCR negative Day 1 through Month 7 to the relevant HPV type.

Who can take part

You may be eligible to participate in the study if you meet the following criteria:


Inclusion Criteria

  1. Healthy
  2. Has not had sex with males or has had sex with males and used effective contraception with no failures since the first day of the participant's last menstrual period through Day 1
  3. Agrees to use effective contraception if has sex with a male partner during study
  4. Has had sexual intercourse with male partners, and has had 1 to 4 male and/or female sexual partners


Exclusion Criteria

  1. History of a positive test for HPV
  2. History of an abnormal Pap test result showing ASC-US, atypical squamous cells - cannot exclude HSIL (high grade squamous intraepithelial lesion [(ASC-H)], low-grade squamous intraepithelial lesion (LSIL), HSIL), or atypical glandular cells
  3. History of an abnormal cervical biopsy result showing CIN, adenocarcinoma in situ or cervical cancer
  4. History of or clinical evidence at the Day 1 gynecologic examination of HPV-related anogenital diseases (e.g., genital warts, VIN, VaIN, AIN, vulvular cancer, vaginal cancer or anal cancer
  5. Does not have an intact cervix uteri or has more than one cervix uteri
  6. Is pregnant
  7. Known allergy to any vaccine component, including aluminum, yeast, or Benzonase™ (nuclease, Nycomed™ [used to remove residual nucleic acids from this and other vaccines])
  8. History of severe allergic reaction (e.g., swelling of the mouth and throat, difficulty breathing, hypotension or shock) that required medical intervention
  9. Has thrombocytopenia or any coagulation disorder that would contraindicate intramuscular injections
  10. Currently immunocompromised or has been diagnosed as having a 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
  11. Has had a splenectomy
  12. Is expecting to donate eggs during Day 1 through Month 7 of the study
  13. Plans to receive during Day 1 through Month 7 of the study, is receiving or has received within 12 months prior to enrollment the following immunosuppressive therapies: radiation therapy, cyclophosphamide, azathioprine, methotrexate, any chemotherapy, cyclosporin, leflunomide (Arava™), tumor necrosis factor (TNF)-α antagonists, monocolonal 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 she 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 high dose 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.
  14. Plans to receive during Day 1 through Month 7 of the study, is receiving or has received within the 6 months prior to the Day 1 vaccination any immune globulin product (including RhoGAM™) or blood derived product other than IVIG
  15. Has received a marketed HPV vaccine, or has participated in an HPV vaccine clinical study and has received either active agent or placebo
  16. Concurrently enrolled in clinical studies of investigational agents or studies involving collection of cervical specimens
  17. User of recreational or illicit drugs or has had a recent history (within the last year) of drug or alcohol abuse or dependence at the discretion of the investigator. Alcohol abusers are defined as those who drink despite recurrent social, interpersonal, and/or legal problems as a result of alcohol use

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Study Locations

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How to Apply

Contact the study center to learn if this study is a good match for you.

Study’s details


Papillomavirus Infections

Age (in years)

20 - 45


Phase 3

Participants needed


Est. Completion Date

Mar 31, 2028

Treatment type



Merck Sharp & Dohme LLC identifier


Study number


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