CLINICAL TRIALS PROFILE FOR ISONIAZID; PYRAZINAMIDE; RIFAMPIN

All Clinical Trials for isoniazid; pyrazinamide; 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.
NCT00000950 ↗	Metabolism of Antituberculosis Drugs in HIV-Infected Persons With Tuberculosis	Completed	National Institute of Allergy and Infectious Diseases (NIAID)	N/A	1969-12-31	The purpose of this study is to determine if a relationship exists between the level of antituberculosis drugs (isoniazid, rifampin, ethambutol, and pyrazinamide) in the blood and the outcome of HIV-positive patients with tuberculosis. This study also evaluates how these drugs are absorbed and metabolized in the body.
NCT00001033 ↗	The Treatment of Tuberculosis in HIV-Infected Patients	Completed	National Institute of Allergy and Infectious Diseases (NIAID)	Phase 3	1969-12-31	PER 5/30/95 AMENDMENT: To compare the combined rate of failure during therapy and relapse after therapy between two durations of intermittent therapy (6 versus 9 months) for the treatment of pulmonary tuberculosis (TB) in HIV-infected patients. To compare toxicity, survival, and development of resistance in these two regimens. ORIGINAL: To compare the efficacy and safety of induction and continuation therapies for the treatment of pulmonary TB in HIV-infected patients who are either from areas with known high rates of resistance to one or more anti-TB drugs or from areas where TB is expected to be susceptible to commonly used anti-TB drugs. PER 5/30/95 AMENDMENT: In HIV-negative patients, intermittent anti-TB therapy has been shown to be as effective as daily therapy, but the optimal duration of therapy in HIV-infected patients has not been established. ORIGINAL: In some areas of the country, resistance to one or more of the drugs commonly used to treat TB has emerged. Thus, the need to test regimens containing a new drug exists. Furthermore, the optimal duration of anti-TB therapy for HIV-infected patients with TB needs to be determined.
NCT00023374 ↗	TBTC Study 24: Intermittent Treatment of TB With Isoniazid Resistance or Intolerance	Completed	US Department of Veterans Affairs	N/A	2000-08-01	This study is a prospective, open-label, nonrandomized trial using a largely-intermittent, six-month tuberculosis treatment regimen among patients who will not receive isoniazid due to the presence of initial isoniazid resistance or intolerance. Subjects are enrolled after resistance or intolerance to isoniazid has been documented, and are treated for a total of six months (nine months if baseline chest x-ray shows cavitation and 2-month sputum culture is positive) with twice weekly or thrice weekly rifampin, ethambutol, and pyrazinamide.

Clinical Trial Conditions for isoniazid; pyrazinamide; rifampin

Condition Name

Condition Name for isoniazid; pyrazinamide; rifampin
Intervention	Trials
Tuberculosis	22
Tuberculosis, Pulmonary	8
HIV Infections	7
Pulmonary Tuberculosis	6

Condition MeSH

Condition MeSH for isoniazid; pyrazinamide; rifampin
Intervention	Trials
Tuberculosis	39
Tuberculosis, Pulmonary	18
HIV Infections	8
Infections	7

Clinical Trial Locations for isoniazid; pyrazinamide; rifampin

Trials by Country

Trials by Country for isoniazid; pyrazinamide; rifampin
Location	Trials
United States	119
China	39
South Africa	19
Canada	16
Brazil	10

Trials by US State

Trials by US State for isoniazid; pyrazinamide; rifampin
Location	Trials
New York	10
California	10
Texas	9
Maryland	8
New Jersey	7

Clinical Trial Progress for isoniazid; pyrazinamide; rifampin

Clinical Trial Phase

Clinical Trial Phase for isoniazid; pyrazinamide; rifampin
Clinical Trial Phase	Trials
PHASE3	2
Phase 4	7
Phase 3	9

Clinical Trial Status

Clinical Trial Status for isoniazid; pyrazinamide; rifampin
Clinical Trial Phase	Trials
Completed	23
Recruiting	6
Not yet recruiting	5

Clinical Trial Sponsors for isoniazid; pyrazinamide; rifampin

Sponsor Name

Sponsor Name for isoniazid; pyrazinamide; rifampin
Sponsor	Trials
National Institute of Allergy and Infectious Diseases (NIAID)	8
Centers for Disease Control and Prevention	8
Johns Hopkins University	5

Sponsor Type

Sponsor Type for isoniazid; pyrazinamide; rifampin
Sponsor	Trials
Other	120
U.S. Fed	12
NIH	9

Clinical Trials Update, Market Analysis and Projection for Isoniazid + Pyrazinamide + Rifampin (Rifater and Descendants)

Last updated: April 25, 2026

What is the current clinical and market picture for the fixed-dose regimen?

Isoniazid, pyrazinamide, and rifampin in fixed-dose combinations are established first-line products used for tuberculosis (TB) treatment, typically in multi-drug regimens for drug-susceptible pulmonary TB and in some forms of latent TB prevention workflows when combined with other agents. The commercial core remains stable: long-used, scale-driven generic supply with periodic formulation updates, plus incremental demand tied to national TB programs and donor-funded initiatives.

Commercially, the market is driven by:

• TB program procurement cycles (national tenders and donor purchasing)
• Generic price erosion and volume growth, depending on country-specific reimbursement and procurement
• Regulatory and quality certifications (WHO prequalification, national eligibility lists)
• Switching pressure toward rifamycin-based fixed-dose combinations (including 4FDC strategies where applicable), which can compress margins even while total demand remains large

Clinically, the regimen continues to be used as a backbone. The highest near-term “value capture” in development is not replacing the regimen wholesale, but refining dosing, improving tolerability (dispersible or heat-stable formats), expanding pediatric usability, shortening time-to-response in program settings via optimized schedules, and supporting program-scale implementation rather than purely novel pharmacology.

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What is the latest clinical trials activity for this regimen?

A global scan of public registries (primarily ClinicalTrials.gov and WHO-aligned registries) shows limited late-stage differentiation for the classic 3-drug intensive-phase backbone because the combination is already standard-of-care. Trial activity concentrates in:

• Pediatric formulations and dosing verifications (safety, pharmacokinetics, adherence)
• Bioequivalence studies for new fixed-dose formulations (manufacturing changes, FDC tablet or granule updates)
• Programmatic trials comparing regimen delivery strategies (pill burden, dispersible formats, directly observed therapy workflows)
• Interactions within TB regimen platforms (bridging studies where rifamycin combinations are evaluated in broader treatment frameworks)

What that means for an investor or R&D desk: the most actionable clinical signals for this specific triple combination come from formulation-bioequivalence, pediatric bridging, and real-world implementation studies rather than Phase 3 superiority trials against new molecularly targeted TB regimens.

Typical clinical endpoints used in this regimen’s studies

Studies evaluating fixed-dose products and pediatric suitability commonly report:

• Safety and tolerability (hepatotoxicity monitoring, GI events, rash)
• Pharmacokinetics (rifampin exposure, acetylator phenotype effects for isoniazid)
• Treatment adherence metrics (pill counts, missed doses under program delivery)
• Microbiological outcomes when embedded in broader TB protocols (culture conversion timelines as part of multi-drug schedules)

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Which registries and trial types matter most right now?

For this regimen, the practical decision-grade signal usually comes from these trial categories:

1) Bioequivalence and bridging

• New FDC tablet strengths and pediatric-adjusted strengths
• Dispersible or scored tablet formats
• Manufacturing site changes that still require local regulatory bridging

2) Pediatric safety and dosing studies

• Weight-band dosing strategy validation
• Hepatic safety monitoring protocols suitable for children

3) Adherence and delivery implementation

• Directly observed therapy simplification via fewer dosing steps
• Support for community-based care models

Actionable takeaway: if you are evaluating near-term pipeline risk or upside, prioritize applicants tied to procurement eligibility pathways (WHO prequalification readiness and national tender listings) and studies that reduce product discontinuity risk, not late-stage claims of clinical superiority.

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How big is the market for isoniazid + pyrazinamide + rifampin, and how is it segmented?

The market is best understood as a TB regimen procurement market rather than a “single-drug” market. Demand follows incidence and treatment initiation volumes across:

• Drug-susceptible pulmonary TB
• Treatment completion across standard TB programs
• Pediatric TB program components
• Public health tender and donor purchase pipelines

Market segmentation (practical commercial view)

Segment	Buyers	Typical demand driver	Competitive feature
Public sector procurement	National TB programs, procurement agencies	Case detection and initiation	Price, supply reliability, eligibility lists
Donor-funded programs	Global health purchasers	Budget cycles and tender frameworks	WHO-aligned quality approvals
Pediatric channel	Pediatric TB services	Weight-band dosing adoption	Pediatric usability, formulation flexibility
Private sector (limited in many geographies)	Private hospitals/clinics	Affordability and access	Availability and channel distribution

Pricing pressure dynamics

• This regimen’s core components are long-established and heavily generified.
• Competition tends to compress unit margins toward manufacturing and compliance cost levels.
• Product differentiation shifts to:
  • dosing convenience (FDC)
  • quality systems
  • supply chain continuity
  • tender qualification speed

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What is the forecast outlook for demand and sales through 2030?

Directionally positive with margin compression risk. Demand tracks TB program treatment volumes. Even as some jurisdictions shift toward newer fixed-dose combinations and shorter-course regimens, the intensive phase backbone still supports large volumes in drug-susceptible programs and in transition periods where new regimens are not yet fully adopted.

Forecast logic used by procurement-scale markets (scenario framework)

Without relying on a single proprietary forecast model, the near-to-midterm outlook can be approximated by program volumes and adoption speed of newer regimens.

1) Base case demand

• Continued scale-up in TB detection and treatment completion in high-burden countries
• Maintaining standard-of-care intensity-phase regimen backbone

2) Downside demand

• Faster-than-expected adoption of newer regimens that reduce use of the classic intensive-phase triple combination
• Budget tightening and procurement delays during economic shocks

3) Upside demand

• Improved access and treatment coverage (recovery of diagnosis rates post disruptions)
• Faster rollouts of pediatric-optimized FDC packs that reduce regimen discontinuation

Product-level forecast constraints

Sales for any single FDC product depend on:

• Eligibility status for tenders (WHO prequalification or comparable national listings)
• Supply continuity and compliance record
• Shelf-life and logistics suitability for end-user settings
• Competitive tender cycles (price and bid scoring)

Net projection: the class market remains large and stable. Growth is primarily volume-driven, with pricing pressure limiting value growth per unit.

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What competitive landscape pressures shape this market?

The main forces are structural:

• Generic substitution: Fixed-dose products with bioequivalent approvals face fast competitive entry.
• Tender-led procurement: Bids prioritize lowest cost per treatment course among eligible suppliers.
• Formulation consolidation: Some markets consolidate on specific FDC SKUs that meet procurement frameworks.
• Regimen evolution: New TB treatment strategies can shift intensive-phase composition in some settings, but adoption remains uneven across geographies.

Typical competitor set for FDC TB products

Competitor type	Strength	Weakness
WHO-prequalified generics	Faster tender entry, broad access	Margin compression
Local/national generics	Lower landed cost in specific markets	Variable quality consistency and approvals
Brand legacy products	Trust and history	Usually higher price and tender disadvantage
Supply-chain specialists	Strong delivery reliability	Limited differentiation beyond compliance

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What R&D and regulatory path creates the most near-term business upside?

For this regimen, “pipeline” in practice means reformulation and eligibility acceleration:

• Pediatric-friendly formulations (dispersible formats, weight-band strength mapping)
• Heat and humidity stability suitable for high-burden regions
• Bioequivalence and bridging packages that accelerate market entry approvals
• Packaging and adherence optimization aligned with program delivery workflows

Regulatory priority logic: companies that can compress regulatory timelines and secure procurement eligibility are positioned to capture incremental tenders even without new clinical superiority.

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Key risk map for commercialization and investment

1) Pricing and tender compression

• Unit price pressure can outpace volume growth.

2) Regulatory eligibility dependence

• Losing or delaying listing status can cause abrupt sales drops.

3) Program shifts

• New regimens reduce some use cases even when TB burden remains high.

4) Supply-chain and quality exposure

• Batch failures can trigger tender exclusions.

5) Safety monitoring requirements

• Hepatotoxicity and drug-drug interaction management affect protocol adherence and observed tolerability.

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Key Takeaways

• Isoniazid + pyrazinamide + rifampin FDCs remain core standard-of-care components in drug-susceptible TB treatment pathways; clinical differentiation is largely shifting toward formulation, pediatric suitability, and program delivery rather than new clinical superiority.
• Market growth through 2030 is volume-driven via TB program coverage, with heavy margin compression risk from generic competition and tender-led procurement.
• The most actionable near-term upside for suppliers is eligibility and procurement readiness (quality systems and listings), supported by bioequivalence and pediatric bridging, plus packaging and stability designed for end-user settings.
• Competitive advantage is increasingly operational: supply reliability, tender execution, and regulatory timeline control rather than novel pharmacology.

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FAQs

1) Are Phase 3 trials likely to define a new standard for isoniazid + pyrazinamide + rifampin?
For this classic triple combination, most observable trial activity centers on formulation, pediatric bridging, and program implementation rather than superiority Phase 3 replacement.

2) What determines commercial success most for fixed-dose triple TB regimens?
Tender eligibility, procurement qualifications, and supply continuity are typically the binding constraints, with price scoring driving awarded volumes.

3) How do pediatric programs change the commercial opportunity?
Pediatric suitability and dosing usability (weight-band strategies, dispersible formats) can unlock procurement categories that favor pediatric-optimized packs and reduce regimen discontinuation.

4) What is the primary margin risk?
Generic substitution and procurement bid pressure compress unit pricing, so growth tends to come from volume and lifecycle expansions rather than premium pricing.

5) Do newer TB regimens reduce long-term demand for this triple combination?
In some settings they can reduce use, but adoption pace is uneven; the triple backbone remains embedded in many standard workflows during transitions and across drug-susceptible programs.

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References

1. World Health Organization. Guidance for national tuberculosis programmes on the management of tuberculosis in children. WHO; and related TB child guidance updates.
2. World Health Organization. Consolidated guidelines on tuberculosis. Module 4: treatment drug-susceptible tuberculosis treatment. WHO.
3. U.S. National Library of Medicine. ClinicalTrials.gov. Studies for isoniazid + pyrazinamide + rifampin fixed-dose combinations (search results and trial records).