CLINICAL TRIALS PROFILE FOR TWINRIX

All Clinical Trials for TWINRIX

Trial ID	Title	Status	Sponsor	Phase	Start Date	Summary
NCT00316303 ↗	Effectiveness of the Screen, Test, Immunize, Reduce Risk, and Refer (STIRR) Intervention for People With Both a Mental and Substance Abuse Disorder	Completed	National Institute of Mental Health (NIMH)	Phase 2	2006-02-01	This study will determine the effectiveness of the STIRR (Screen, Test, Immunize, Reduce risk, and Refer) intervention in increasing rates of testing, immunization, referral, and treatment for blood-borne diseases, such as hepatitis and HIV, in people with both a mental disorder and a substance abuse disorder.
NCT00316303 ↗	Effectiveness of the Screen, Test, Immunize, Reduce Risk, and Refer (STIRR) Intervention for People With Both a Mental and Substance Abuse Disorder	Completed	Dartmouth-Hitchcock Medical Center	Phase 2	2006-02-01	This study will determine the effectiveness of the STIRR (Screen, Test, Immunize, Reduce risk, and Refer) intervention in increasing rates of testing, immunization, referral, and treatment for blood-borne diseases, such as hepatitis and HIV, in people with both a mental disorder and a substance abuse disorder.
NCT02334462 ↗	Study of the Safety and Immunogenicity of Pfs230D1M-EPA/Alhydrogel and Pfs25M-EPA/Alhydrogel , a Transmission Blocking Vaccine Against Plasmodium Falciparum Malaria, in Adults in the U.S. and Mali	Completed	Rodolphe Merieux Laboratory@@@Bamako, Mali	Phase 1	2015-01-07	Background: - Malaria is a severe infection caused by a parasite. People can get malaria if a mosquito that carries the parasite bites them. Malaria infection does not happen in the United States, but many people in Africa, Asia, and South America are at risk for it. Researchers want to test two vaccines that may help decrease malaria infection. Objective: - To see if two vaccines (Pfs25M-EPA/Alhydrogel and Pfs230DIM-EPA/Alhydrogel ) are safe in humans and cause an immune response that will prevent malaria parasites from correctly growing in the mosquito. Eligibility: - Healthy adults ages 18 50. Design: - There are several groups in this study. Each group will receive a different dose of the vaccine and some groups will received both vaccines. - Vaccinations will be given on two days about 4 weeks apart. - Participants will receive each vaccine as an injection into the arm. Blood will be drawn on the day of vaccination. - In the 4 weeks after receiving a vaccination, participants will have at least 3 clinic visits and 1 phone contact. They will have at least 3 more visits and 3 phone contacts over the next 6 months. - At each visit, participants will be evaluated for side effects to the vaccine and any new health changes or problems. They will be asked how they are feeling and if they have taken any medicine. Blood and urine samples may be taken at the visit. More follow-up visits may be needed to follow up on changes or problems.

Clinical Trial Conditions for TWINRIX

Condition Name

Condition Name for TWINRIX
Intervention	Trials
Depression	1
HIV Infections	1
Malaria	1

Condition MeSH

Condition MeSH for TWINRIX
Intervention	Trials
Disease	1
Malaria, Falciparum	1
Bipolar Disorder	1

Clinical Trial Locations for TWINRIX

Trials by Country

Trials by Country for TWINRIX
Location	Trials
United States	2
Mali	1

Trials by US State

Trials by US State for TWINRIX
Location	Trials
Maryland	2

Clinical Trial Progress for TWINRIX

Clinical Trial Phase

Clinical Trial Phase for TWINRIX
Clinical Trial Phase	Trials
Phase 2	1
Phase 1	1

Clinical Trial Status

Clinical Trial Status for TWINRIX
Clinical Trial Phase	Trials
Completed	2

Clinical Trial Sponsors for TWINRIX

Sponsor Name

Sponsor Name for TWINRIX
Sponsor	Trials
National Institute of Mental Health (NIMH)	1
Dartmouth-Hitchcock Medical Center	1
Rodolphe Merieux Laboratory@@@Bamako, Mali	1

Sponsor Type

Sponsor Type for TWINRIX
Sponsor	Trials
NIH	2
Other	2

Last updated: May 11, 2026

TWINRIX (Hepatitis A and B Vaccine) Clinical Trials Update, Market Analysis and Projection

What is TWINRIX?

TWINRIX is a combination vaccine for prevention of Hepatitis A (HAV) and Hepatitis B (HBV). It is marketed as:

• Adult formulation (commonly used for adults and older adolescents depending on labeling)
• Pediatric formulation (for pediatric populations depending on local regulatory approvals)

Key product attribute: it delivers protection against two viral diseases in a single immunization course, targeting travelers, adults at risk for HAV/HBV, and other vaccination-eligible groups per local schedules.

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What is the clinical development and trial status for TWINRIX?

No active, new global Phase 3 development program specific to TWINRIX was identified in the provided context. The product is established and continuously supplied under licensed indications in multiple jurisdictions, and most recent public trial activity typically focuses on:

• immunogenicity bridging to updated manufacturing lots
• schedule or population sub-studies (e.g., seroprotection endpoints)
• real-world effectiveness studies (observational), rather than new Phase 3 efficacy trials

Practical interpretation for business and investment: TWINRIX is an ongoing marketed biologic with incremental lifecycle activities, not a pipeline asset with a near-term, trial-driven registration pathway in most markets.

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What is the competitive and market structure for HAV/HBV combination vaccination?

Demand drivers

• Travel to endemic HAV regions and higher-risk geographies for HBV exposure
• Adult immunization expansion in routine and risk-based programs
• Healthcare and occupational exposure (HBV risk) and public health catch-up strategies (HAV risk)
• Household and close-contact protection strategies for HBV vaccination in target populations

Competitive set

Competition generally comes from:

• Monovalent HAV vaccines (or HAV + other combinations)
• Monovalent HBV vaccines
• Other combination approaches (where licensed and reimbursed)

TWINRIX’s value proposition is strongest where payers and providers prefer:

• fewer injections
• simplified schedule adherence
• bundled risk protection for HAV and HBV

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What does market analysis indicate for TWINRIX?

Market sizing logic (how the addressable market forms)

The addressable market for TWINRIX is the overlap of:

1. HAV-vaccinated populations (travelers, adult risk groups, some routine schedules)
2. HBV-vaccinated populations (risk-based and routine adult programs)
3. Geographies where combination vaccination is priced and reimbursed to support uptake

Because HAV and HBV vaccines are mature, the market behaves like a label-driven, seasonally sensitive replenishment market with a strong distribution footprint and tender-driven procurement.

Pricing and reimbursement dynamics

• In most markets, tender pricing and tighter procurement cycles influence realized net price.
• Where combination vaccination is reimbursed or explicitly recommended, utilization tends to be steadier.
• In markets where monovalent dosing strategies dominate procurement, combination utilization can face displacement risk.

Supply and manufacturing considerations

For a licensed combination vaccine, throughput and lot release timing influence continuity of supply, which directly impacts tender delivery and provider confidence. This is a key commercial risk in biologics, even without new efficacy trials.

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What is the likely market trajectory and sales projection range for TWINRIX?

A credible forward projection requires a quantified baseline (sales history, geography mix, category growth rates, and reimbursement assumptions) that is not provided in the prompt context. Under the operating constraints, no numerical forecast is produced.

What can be concluded without inventing numbers:

• TWINRIX growth is most sensitive to (a) reimbursement coverage for combination use, (b) adult vaccination program intensity, and (c) travel demand volumes.
• Upside typically comes from expanded adult indications and schedule adoption.
• Downside typically comes from monovalent procurement preference or price compression via tenders.

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What commercialization risks matter most for TWINRIX?

Regulatory lifecycle and label changes

Combination vaccines require periodic regulatory maintenance and post-authorization updates (manufacturing, safety surveillance, and sometimes schedule language). These actions generally preserve market access rather than create major upside.

Competitive displacement

If payers and providers favor:

• separate HAV and HBV dosing pathways, or
• alternate combination products in specific tender regions, then TWINRIX can face utilization pressure even if overall vaccine category demand grows.

Reference pricing and tender pressure

Because the market is mature, competitive contracting can drive real price declines while volumes grow modestly.

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What is the bottom-line investment and R&D implication?

• Clinical trial intensity for TWINRIX is not the primary driver; market access, tender execution, and reimbursement coverage drive performance.
• The product’s lifecycle is supported by ongoing immunogenicity and quality/regulatory maintenance activities rather than late-stage efficacy trials.
• The highest-leverage commercial actions are procurement positioning and payer/provider alignment for combination preference.

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Key Takeaways

• TWINRIX is a mature, licensed HAV/HBV combination vaccine; the market behaves as a routine and risk-based procurement cycle.
• In the provided context, there is no identified new Phase 3 development that would change the product’s registration trajectory.
• Commercial performance is most sensitive to reimbursement and tender behavior, adult vaccination intensity, and travel-linked demand.
• Without quantified baseline inputs, no numeric sales projection is issued.

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FAQs

1) Is TWINRIX still under active clinical trial development?
TWINRIX is primarily a marketed product; activity is typically limited to lifecycle and immunogenicity/schedule studies rather than new Phase 3 efficacy programs in most jurisdictions.

2) What drives TWINRIX demand?
Demand concentrates in travelers, adult risk groups, healthcare and occupational settings, and regions or programs that reimburse combination vaccination.

3) What is the biggest commercial threat to TWINRIX?
Tender-driven price compression and procurement preference for separate monovalent HAV and HBV vaccination pathways.

4) Why do combination vaccines like TWINRIX win in some markets?
They reduce injection burden and can simplify adherence for two infections in one course, which supports adoption when payers and providers favor bundled protection.

5) What would most likely change TWINRIX’s market outlook?
Large shifts in reimbursement policy for combination vaccination, changes in national adult immunization strategy, or material changes in competitive contracting.

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References (APA)

[1] GlaxoSmithKline. TWINRIX prescribing information / product information (various regions).
[2] European Medicines Agency (EMA). TWINRIX EPAR and related regulatory documents.
[3] U.S. Food and Drug Administration (FDA). TWINRIX product labeling and regulatory history.