Last reviewed · How we verify

V503 Vaccine

Merck Sharp & Dohme LLC · Phase 3 active Biologic ✓ Verified May 2026

V503 Vaccine is a Vaccine Biologic drug developed by Merck Sharp & Dohme LLC. It is currently in Phase 3 development for Prevention of cervical, vulvar, vaginal, and anal cancers caused by HPV types 16 and 18 in females aged 9 to 26 years.

V503 Vaccine works by stimulating the body's immune system to produce antibodies against the human papillomavirus (HPV) types 16 and 18.

The V503 vaccine is a multivalent human papillomavirus (HPV) L1 virus-like particle (VLP) vaccine used to prevent cervical cancers, vulvar cancer, vaginal cancer, genital lesions, and PAP test abnormalities. It induces an immune response through its biological vaccine mechanism as a component of a vaccine.

Likelihood of approval
63.3% vs 58.3% industry baseline
If approved by FDA: likely 2028–2030
Steps remaining: NDA/BLA submission
Confidence: High
Why this estimate
  • Baseline phase 3 → approval rate +58.3pp
    Industry-wide phase 3 drugs reach approval ~58.3% of the time (BIO/Informa 2023 industry benchmark across all therapeutic areas).
  • Anti-infectives pathway favourability +2.0pp
    Microbiological endpoints + non-inferiority designs raise approval rates above baseline.
  • Big-pharma sponsor +3.0pp
    Merck Sharp & Dohme LLC is a top-20 pharma sponsor — historical approval rates run ~3pp above average due to scale, regulatory experience, and trial-design quality.
Predicted approval windows by jurisdiction (conditional on FDA approval)
Regulator Country Likely year Lag vs FDA
FDA US 2028–2030
EMA EU 2029–2031 +0.7 yr
MHRA GB 2029–2031 +0.7 yr
Health Canada CA 2029–2032 +0.9 yr
TGA AU 2029–2032 +1.2 yr
PMDA JP 2029–2032 +1.5 yr
NMPA CN 2030–2033 +2.3 yr
MFDS KR 2029–2032 +1.4 yr
CDSCO IN 2029–2033 +1.8 yr
ANVISA BR 2030–2033 +2.3 yr

Hover any row for the lag rationale. Lag estimates are reduced when the drug has FDA Breakthrough or EMA PRIME designation (sponsors file globally in parallel).

Estimate based on the BIO/Informa industry phase transition rates plus per-drug modifiers for therapeutic area, sponsor type, FDA designations, mechanism, and trial design. Per-jurisdiction lags from Tufts CSDD international approval studies. Not investment, clinical or regulatory advice. Methodology: /methodology#likelihood.

At a glance

Generic nameV503 Vaccine
SponsorMerck Sharp & Dohme LLC
Drug classVaccine
ModalityBiologic
Therapeutic areaInfectious Disease
PhasePhase 3

Mechanism of action

This vaccine is a non-replicating virus-like particle (VLP) vaccine that contains the L1 protein of HPV types 16 and 18. Upon administration, the L1 protein is taken up by antigen-presenting cells, which then present the protein to T-cells, stimulating an immune response against the HPV types 16 and 18.

Approved indications

Common side effects

Key clinical trials

Primary sources

Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.

SourceUsed for
ClinicalTrials.govTrial enrolment, design, endpoints, results

Competitive intelligence

For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:

Frequently asked questions about V503 Vaccine

What is V503 Vaccine?

V503 Vaccine is a Vaccine drug developed by Merck Sharp & Dohme LLC, indicated for Prevention of cervical, vulvar, vaginal, and anal cancers caused by HPV types 16 and 18 in females aged 9 to 26 years.

How does V503 Vaccine work?

V503 Vaccine works by stimulating the body's immune system to produce antibodies against the human papillomavirus (HPV) types 16 and 18.

What is V503 Vaccine used for?

V503 Vaccine is indicated for Prevention of cervical, vulvar, vaginal, and anal cancers caused by HPV types 16 and 18 in females aged 9 to 26 years.

Who makes V503 Vaccine?

V503 Vaccine is developed by Merck Sharp & Dohme LLC (see full Merck Sharp & Dohme LLC pipeline at /company/merck).

What drug class is V503 Vaccine in?

V503 Vaccine belongs to the Vaccine class. See all Vaccine drugs at /class/vaccine.

What development phase is V503 Vaccine in?

V503 Vaccine is in Phase 3.

What are the side effects of V503 Vaccine?

Common side effects of V503 Vaccine include Injection site pain, Fatigue, Headache.

Related

Primary sources · FDA · ClinicalTrials.gov · EMA · SEC EDGAR · ChEMBL · Wikidata · full sourcing