CLINICAL TRIALS PROFILE FOR ISONIAZID; RIFAMPIN

All Clinical Trials for ISONIAZID; RIFAMPIN

Trial ID	Title	Status	Sponsor	Phase	Start Date	Summary
NCT00000636 ↗	Prophylaxis Against Tuberculosis (TB) in Patients With Human Immunodeficiency Virus (HIV) Infection and Confirmed Latent Tuberculous Infection	Completed	National Institute of Allergy and Infectious Diseases (NIAID)	N/A	1969-12-31	To evaluate and compare the effectiveness of a 2-month regimen of rifampin and pyrazinamide versus a 1-year course of isoniazid (INH) to prevent the development of tuberculosis in patients who are coinfected with HIV and latent Mycobacterium tuberculosis (MTb). Current guidelines recommend 6 to 12 months of treatment with INH for purified protein derivative (PPD)-positive individuals. Problems with this treatment include compliance, adverse reaction, and the possibility of not preventing disease due to INH-resistant organisms. Studies suggest that two or three months of rifampin and pyrazinamide may be more effective than longer courses of INH. A two-month prevention course should help to increase compliance. In addition, the use of two drugs (rifampin and pyrazinamide) may help overcome problems with drug resistance.
NCT00000638 ↗	Preventive Treatment Against Tuberculosis (TB) in Patients With Human Immunodeficiency Virus (HIV) Infection and Confirmed Latent Tuberculous Infection	Completed	Hoechst Marion Roussel	N/A	1969-12-31	To evaluate and compare the safety and effectiveness of a one-year course of isoniazid (INH) versus a two-month course of rifampin plus pyrazinamide for the prevention of reactivation tuberculosis in individuals infected with both HIV and latent (inactive) Mycobacterium tuberculosis. Current guidelines from the American Thoracic Society and the Centers for Disease Control recommend 6 to 12 months of INH for PPD (purified protein derivative)-positive individuals. Although the effectiveness of this treatment is not known for HIV-infected individuals, several studies using INH to prevent tuberculosis in presumably normal hosts have shown 60 to 80 percent effectiveness. Problems with this treatment include compliance, adverse reaction, and the possibility of not preventing disease due to tuberculosis organisms being resistant to INH. A two-month preventive treatment plan should help in increasing compliance. In addition, the use of two drugs (rifampin / pyrazinamide) may help overcome problems with drug resistance. If this study shows equal or greater effectiveness of the two-month rifampin / pyrazinamide treatment, it could alter the approach to tuberculosis prevention for both HIV-positive and HIV-negative individuals.
NCT00000638 ↗	Preventive Treatment Against Tuberculosis (TB) in Patients With Human Immunodeficiency Virus (HIV) Infection and Confirmed Latent Tuberculous Infection	Completed	Lederle Laboratories	N/A	1969-12-31	To evaluate and compare the safety and effectiveness of a one-year course of isoniazid (INH) versus a two-month course of rifampin plus pyrazinamide for the prevention of reactivation tuberculosis in individuals infected with both HIV and latent (inactive) Mycobacterium tuberculosis. Current guidelines from the American Thoracic Society and the Centers for Disease Control recommend 6 to 12 months of INH for PPD (purified protein derivative)-positive individuals. Although the effectiveness of this treatment is not known for HIV-infected individuals, several studies using INH to prevent tuberculosis in presumably normal hosts have shown 60 to 80 percent effectiveness. Problems with this treatment include compliance, adverse reaction, and the possibility of not preventing disease due to tuberculosis organisms being resistant to INH. A two-month preventive treatment plan should help in increasing compliance. In addition, the use of two drugs (rifampin / pyrazinamide) may help overcome problems with drug resistance. If this study shows equal or greater effectiveness of the two-month rifampin / pyrazinamide treatment, it could alter the approach to tuberculosis prevention for both HIV-positive and HIV-negative individuals.
NCT00000638 ↗	Preventive Treatment Against Tuberculosis (TB) in Patients With Human Immunodeficiency Virus (HIV) Infection and Confirmed Latent Tuberculous Infection	Completed	National Institute of Allergy and Infectious Diseases (NIAID)	N/A	1969-12-31	To evaluate and compare the safety and effectiveness of a one-year course of isoniazid (INH) versus a two-month course of rifampin plus pyrazinamide for the prevention of reactivation tuberculosis in individuals infected with both HIV and latent (inactive) Mycobacterium tuberculosis. Current guidelines from the American Thoracic Society and the Centers for Disease Control recommend 6 to 12 months of INH for PPD (purified protein derivative)-positive individuals. Although the effectiveness of this treatment is not known for HIV-infected individuals, several studies using INH to prevent tuberculosis in presumably normal hosts have shown 60 to 80 percent effectiveness. Problems with this treatment include compliance, adverse reaction, and the possibility of not preventing disease due to tuberculosis organisms being resistant to INH. A two-month preventive treatment plan should help in increasing compliance. In addition, the use of two drugs (rifampin / pyrazinamide) may help overcome problems with drug resistance. If this study shows equal or greater effectiveness of the two-month rifampin / pyrazinamide treatment, it could alter the approach to tuberculosis prevention for both HIV-positive and HIV-negative individuals.

Clinical Trial Conditions for ISONIAZID; RIFAMPIN

Condition Name

Condition Name for ISONIAZID; RIFAMPIN
Intervention	Trials
Tuberculosis	30
Tuberculosis, Pulmonary	8
HIV Infections	8
Pulmonary Tuberculosis	7

Condition MeSH

Condition MeSH for ISONIAZID; RIFAMPIN
Intervention	Trials
Tuberculosis	53
Tuberculosis, Pulmonary	21
Infections	10
HIV Infections	9

Clinical Trial Locations for ISONIAZID; RIFAMPIN

Trials by Country

Trials by Country for ISONIAZID; RIFAMPIN
Location	Trials
United States	141
China	40
Canada	27
South Africa	20
Brazil	14

Trials by US State

Trials by US State for ISONIAZID; RIFAMPIN
Location	Trials
New York	13
California	13
Texas	11
Maryland	9
Illinois	9

Clinical Trial Progress for ISONIAZID; RIFAMPIN

Clinical Trial Phase

Clinical Trial Phase for ISONIAZID; RIFAMPIN
Clinical Trial Phase	Trials
PHASE3	3
PHASE2	1
Phase 4	11

Clinical Trial Status

Clinical Trial Status for ISONIAZID; RIFAMPIN
Clinical Trial Phase	Trials
Completed	31
RECRUITING	7
Not yet recruiting	6

Clinical Trial Sponsors for ISONIAZID; RIFAMPIN

Sponsor Name

Sponsor Name for ISONIAZID; RIFAMPIN
Sponsor	Trials
National Institute of Allergy and Infectious Diseases (NIAID)	11
Centers for Disease Control and Prevention	10
Johns Hopkins University	5

Sponsor Type

Sponsor Type for ISONIAZID; RIFAMPIN
Sponsor	Trials
Other	135
U.S. Fed	16
NIH	12

Last updated: July 28, 2026

Isoniazid + Rifampin Clinical Trials Update, Market Analysis, and 2025–2035 Projections

Isoniazid (INH) plus rifampin is a first-line tuberculosis (TB) regimen used in multiple indications including latent TB infection (LTBI) and active TB treatment as part of combination therapy. Market activity centers on fixed-dose and combination-dose products, regulatory renewals for existing formulations, and ongoing trials exploring shortened regimens and optimized dosing schedules rather than new chemical entities. Commercial projections are driven by LTBI screening intensity, TB program funding, and country-level procurement cycles, with competitive pressure from generics and multiple-source supply of INH and rifampin combination products.

The clinical-trials landscape is dominated by regimen-combination optimization (duration, adherence-support approaches, and safety in special populations) rather than brand-new INH-rifampin mechanisms. Forecast growth is constrained by mature generic supply, pricing compression, and payer procurement practices in high-burden countries.

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What clinical trials are updating for isoniazid and rifampin (INH-RIF) in 2024–2026?

Featured snippet answer

Recent trial activity for INH + rifampin focuses on LTBI treatment duration reduction and regimen simplification, plus safety and adherence outcomes in populations including household contacts, HIV co-infected patients, children, and people with comorbidities.

Key trial themes showing up across INH-RIF studies

• LTBI shorter-course regimens: trials evaluate whether INH-RIF combinations can reduce time-to-completion while maintaining comparable efficacy and tolerability.
• Adherence and programmatic delivery: endpoints include completion rates, missed-dose patterns, and adverse-event-driven discontinuation.
• Special populations: safety and pharmacokinetics in HIV, pediatrics, and hepatic-risk groups.
• Drug-drug interactions: assessments in patients on antiretroviral therapy or other hepatically metabolized drugs.

Common endpoints used in INH-RIF regimen trials

• LTBI conversion and microbiologic outcomes where applicable
• TB incidence during follow-up (primary endpoint in many LTBI studies)
• Treatment completion and time-to-discontinuation
• Liver enzyme elevation frequency and severity (ALT/AST thresholds)
• Serious adverse events and discontinuation rates

What to watch in protocol updates

• Changes to hepatic monitoring schedules and stopping rules
• Dose modifications or stratified dosing by body weight or comorbidity
• Updated comparator arms reflecting evolving WHO/NTCA program recommendations in participating countries

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What outcomes matter most for INH plus rifampin regimens in latent TB infection (LTBI)?

Primary clinical differentiation points

In LTBI, regimen performance is judged less by “cure” and more by preventing progression to active TB with acceptable tolerability.

Efficacy proxy metrics

• TB disease incidence over defined follow-up intervals
• Adherence-adjusted treatment effects in intention-to-treat and per-protocol analyses

Tolerability metrics

• Hepatotoxicity incidence (ALT/AST thresholds, bilirubin-linked injury, clinical hepatitis)
• Rash and hypersensitivity rates
• Gastrointestinal adverse events impacting completion

Programmatic metrics

• Completion rate within target timeframe
• Early discontinuation drivers (hepatotoxicity vs. access barriers vs. adverse events)

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How does INH-RIF compare with isoniazid-only or rifamycin-containing alternatives for TB prevention?

Featured snippet answer

INH-only regimens typically face lower completion than shorter rifamycin-containing regimens, while rifampin-containing regimens trade off higher rifamycin-related interaction management and pill burden complexity against improved adherence.

Competitive comparator categories

• Isoniazid monotherapy (historical LTBI backbone in many countries)
• Rifamycin-containing shorter regimens (often favored for completion and time-to-protection)
• Combination regimens that avoid INH (in settings where INH resistance or intolerance is operationally salient)

What drives relative adoption

• Completion rate and clinic workflow fit
• Monitoring intensity feasibility (especially hepatic monitoring)
• Drug interaction complexity where HIV programs are integrated with TB prevention

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When does INH + rifampin lose exclusivity and how does that affect clinical supply?

Featured snippet answer

For INH and rifampin combination products, exclusivity and patent leverage is generally limited by long-standing generic availability; supply is driven more by procurement and manufacturing capacity than by remaining branded IP.

Market structure implications

• Multiple suppliers dominate most national formularies
• Pricing is set by procurement tenders, essential medicines frameworks, and competition among generics
• Regulatory focus shifts to quality, bioequivalence, and stability rather than IP-driven barriers

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What is the market size for isoniazid + rifampin and what are the drivers of demand?

Featured snippet answer

Demand is primarily tethered to TB prevention programs, LTBI screening capacity, and active TB regimen usage in combination therapy contexts, with growth constrained by generic pricing and substitution into other shorter-course prevention regimens.

Demand drivers

• LTBI screening scale-up: more contact investigations and risk-based screening increases total treatment courses.
• Program funding cycles: Global Fund and national TB budgets create procurement spikes and multi-year continuity.
• WHO guidance uptake: adoption patterns influence how many patients receive INH-RIF vs alternative shorter regimens.
• Adherence improvements: fixed-dose or simplified course structures increase completion, which increases repeat procurement.

Constraint factors

• Hepatotoxicity management: increased monitoring requirements can deter scale-up in low-resource settings.
• Drug interaction burden in HIV care: rifampin’s induction of drug-metabolizing enzymes can complicate antiretroviral selection.
• Procurement price compression: generics depress margins and limit revenue growth even when volume rises.

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How should 2025–2030 revenue and volume be projected for INH-RIF products?

Featured snippet answer

Projections should be modeled as a volume-led market with pricing declining or flat in most procurement-driven settings, with moderate growth tied to LTBI program expansion and stable active TB regimen needs.

Projection framework (used for regimen-market forecasting)

1. Estimate addressable patient pool
   • LTBI eligible based on screening coverage and risk strata
   • Active TB regimen contributions where INH-RIF appears as a component regimen
2. Apply regimen adoption share
   • Market share for INH-RIF within prevention portfolios
3. Apply adherence-linked completion adjustment
   • Courses completed drive repeat procurement cycles and program success metrics
4. Apply price trajectory
   • Generic competitive pricing, tender-based discounts, and margin compression
5. Incorporate manufacturing and regulatory throughput
   • Product availability and shelf-life stability in target markets

Base-case outcome (directional)

• Volume: modest to mid-single digit annual growth in many high-burden geographies if screening expands.
• Value: low growth due to price compression, with occasional spikes aligned to procurement cycles.

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What countries are likely to account for the largest INH-RIF demand?

Featured snippet answer

High-burden TB countries with mature procurement channels for essential medicines are the main demand base, typically including South and Southeast Asia and parts of sub-Saharan Africa.

Where demand concentrates operationally

• High notification and screening programs for household contacts and risk groups
• National TB programs that follow short-course prevention strategies
• HIV-integrated TB prevention programs needing careful drug interaction management

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Which formulations and dosing formats dominate the INH plus rifampin market?

Featured snippet answer

Market demand concentrates in conventional oral solid dosage forms, including combination products where available, plus multi-tablet regimens delivered via programmatic supply chains.

Key formulation variables that affect uptake

• Fixed-dose combinations vs. co-packaged components
• Pediatric weight-band dosing
• Stability in heat and humidity for field distribution
• Bioequivalence and manufacturability for multiple-source supply

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What generic entry risks exist for isoniazid + rifampin combination products?

Featured snippet answer

Entry risk is generally low in terms of clinical development because these are mature molecules; the main risks are regulatory readiness, manufacturing quality systems, and tender qualification rather than scientific novelty.

Practical barriers to entry

• Establishing and maintaining bioequivalence and quality release testing
• Scaling production to tender volumes without batch failures
• Passing local regulator dossier requirements and pharmacovigilance readiness
• Achieving acceptable shelf-life for procurement deadlines

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What regulatory and FDA pathway issues affect INH-RIF products?

Featured snippet answer

In the US, most INH-RIF combination products are supplied through abbreviated or generic pathways where applicable, with emphasis on chemistry manufacturing controls, bioequivalence, and labeling compliance rather than clinical endpoints.

Key regulatory considerations

• Bioequivalence for combination and fixed-dose products
• Hepatic safety labeling consistency and post-marketing reporting practices
• Pediatric labeling requirements where weight-based dosing is used

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How strong is the commercial position versus competing TB prevention regimens (strategy view)?

Featured snippet answer

INH-RIF competes on adherence and course length versus INH-only and competes on safety and interaction burden versus alternative shorter-course rifamycin regimens.

Commercial strategy levers

• Fixed-dose simplification and weight-band dosing to improve completion
• Program partnerships tied to TB/HIV integrated care
• Tender responsiveness with predictable supply and quality performance

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Key Takeaways

• INH + rifampin clinical updates in 2024–2026 center on regimen optimization for LTBI and special-population safety rather than new mechanisms.
• Market demand is driven by LTBI screening expansion and procurement cycles, while value growth is capped by generic price compression.
• Forecasting should be volume-led with cautious value growth assumptions.
• Competitive dynamics are mainly tender- and manufacturing-quality driven, with formulation format influencing adherence and uptake.

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FAQs

1. Are INH plus rifampin regimens preferred for household contacts compared with isoniazid-only strategies?
2. What monitoring protocol changes most often appear in INH-RIF trial protocols for hepatotoxicity?
3. How do rifampin drug-drug interactions affect regimen selection in HIV co-infected patients?
4. Do fixed-dose INH-RIF products improve treatment completion versus co-packaged components?
5. Which bottlenecks most often delay generic INH-RIF product market entry: regulatory, manufacturing, or procurement qualifications?

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References (APA)

1. World Health Organization. (2023). Guidelines on tuberculosis preventive treatment. WHO.
2. Centers for Disease Control and Prevention. (2020). Latent tuberculosis infection: Treatment regimens. CDC.
3. ClinicalTrials.gov. (2024–2026). Search results for “isoniazid rifampin latent TB” and “isoniazid rifampin TB prevention”. National Library of Medicine.