CLINICAL TRIALS PROFILE FOR RIFAMPIN AND ISONIAZID

All Clinical Trials for Rifampin And Isoniazid

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.
NCT00000796 ↗	A Prospective Study of Multidrug Resistance and a Pilot Study of the Safety of and Clinical and Microbiologic Response to Levofloxacin in Combination With Other Antimycobacterial Drugs for Treatment of Multidrug-Resistant Pulmonary Tuberculosis (MDR	Completed	National Institute of Allergy and Infectious Diseases (NIAID)	N/A	1969-12-31	To determine the demographic, behavioral, clinical, and geographic risk factors associated with the occurrence of multidrug-resistant pulmonary tuberculosis (MDRTB). To evaluate the clinical and microbiological responses and overall survival of MDRTB patients who are treated with levofloxacin-containing multiple-drug regimens chosen from a hierarchical list. Per 9/28/94 amendment, to assess whether persistent or recurrent positive sputum cultures of patients who show failure or relapse are due to the same strain or reinfection with a new strain. Among TB patients, there has been an increase in progressive disease due to the emergence of antimycobacterial drug-resistant strains of Mycobacterium tuberculosis. Failure to identify patients at high risk for MDRTB increases the hazard for both treatment failure and development of resistance to additional therapeutic agents. Efforts to improve survival in patients with MDRTB will depend on improved methods of assessing the risk of acquisition of MDRTB and identifying drug susceptibility patterns in a timely fashion.
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.

Clinical Trial Conditions for Rifampin And Isoniazid

Condition Name

Condition Name for Rifampin And Isoniazid
Intervention	Trials
Tuberculosis	30
Tuberculosis, Pulmonary	8
HIV Infections	8
Pulmonary Tuberculosis	7

Condition MeSH

Condition MeSH for Rifampin And Isoniazid
Intervention	Trials
Tuberculosis	53
Tuberculosis, Pulmonary	21
Infections	10
Infection	9

Clinical Trial Locations for Rifampin And Isoniazid

Trials by Country

Trials by Country for Rifampin And Isoniazid
Location	Trials
United States	141
China	40
Canada	27
South Africa	20
Brazil	14

Trials by US State

Trials by US State for Rifampin And Isoniazid
Location	Trials
California	13
New York	13
Texas	11
Maryland	9
Illinois	9

Clinical Trial Progress for Rifampin And Isoniazid

Clinical Trial Phase

Clinical Trial Phase for Rifampin And Isoniazid
Clinical Trial Phase	Trials
PHASE3	3
PHASE2	1
Phase 4	11

Clinical Trial Status

Clinical Trial Status for Rifampin And Isoniazid
Clinical Trial Phase	Trials
Completed	31
Recruiting	7
Not yet recruiting	6

Clinical Trial Sponsors for Rifampin And Isoniazid

Sponsor Name

Sponsor Name for Rifampin And Isoniazid
Sponsor	Trials
National Institute of Allergy and Infectious Diseases (NIAID)	11
Centers for Disease Control and Prevention	10
National Taiwan University Hospital	5

Sponsor Type

Sponsor Type for Rifampin And Isoniazid
Sponsor	Trials
Other	135
U.S. Fed	16
NIH	12

Rifampin And Isoniazid Market Analysis and Financial Projection

Last updated: April 28, 2026

Rifampin and Isoniazid: Clinical Trials Update and Market Analysis With Projection

What is the current clinical-trials landscape for rifampin plus isoniazid?

High-confidence status: rifampin and isoniazid are established first-line anti-tuberculosis (TB) drugs, used in multi-drug regimens. The clinical-trials environment is dominated by regimen optimization, safety/tolerability in specific populations, and pharmacokinetic (PK)/bioequivalence work rather than de novo efficacy trials for a fixed combination.

Where active trials typically cluster

1. TB treatment regimen strategy
   • Studies of treatment duration and regimen composition in drug-susceptible TB, including extensions, intensification phases, and post-intensive continuation approaches.
2. Population-specific safety and exposure
   • Trials in HIV co-infection, pregnancy, pediatric/adolescent populations, and patients with comorbid liver risk where exposure management is central.
3. PK and formulation work
   • Studies using rifampin/isoniazid exposure endpoints to optimize dosing, with common endpoints including Cmax, AUC, time-to-steady-state, and metabolite exposure.

Operational implication for R&D and licensing

• For most investors and partners, the “rifampin + isoniazid” combination is less about proving the core efficacy and more about regimen fit, exposure matching, and label-relevant differentiation such as:
  • lower pill burden (fixed-dose combinations, co-packaged products)
  • improved adherence and simplified dosing schedules
  • better tolerability management strategies in high-risk populations

Evidence base (public registry)

• Trial activity is trackable through ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform (ICTRP) because rifampin/isoniazid studies are typically registered as individual regimen studies rather than as a single “brand” program. (See sources list for the registries.)
  • ClinicalTrials.gov: https://clinicaltrials.gov/
  • WHO ICTRP search: https://trialsearch.who.int/

Which market segments drive demand for rifampin + isoniazid?

Demand for rifampin and isoniazid is driven by TB incidence burden and treatment guideline adoption globally. The combination’s role is anchored in:

• Drug-susceptible TB
• Latent TB infection (LTBI) treatment strategies (where isoniazid is central; rifampin appears in alternative regimens, but rifampin plus isoniazid also appears in certain regimen definitions and older/legacy protocols)

Industry framing that matters for forecasting

• The market is not a single “fixed-dose combination” market; it is a drug substance and regimen market.
• Forecasts should be built from:
  1. TB treated-patient volume
  2. portion on regimens that include isoniazid
  3. rifampin exposure share by regimen
  4. uptake by geography and health-system procurement
  5. price and tender dynamics for generics

What is the addressable global market and how to project it?

A practical projection approach is to model three layers:

1. Total TB patient starts (supply demand driver)
2. Isoniazid exposure share by regimen (most drug-susceptible pathways and many LTBI strategies use isoniazid)
3. Rifampin exposure share by regimen (rifampin-containing regimens dominate drug-susceptible treatment)

Guideline anchor

• WHO TB guidance uses rifampin and isoniazid-containing regimens as core components in drug-susceptible TB management. Current and historical WHO regimen recommendations are published in WHO TB treatment guidelines and consolidated module updates. (See sources.)
  • WHO TB guidelines repository: https://www.who.int/teams/global-tuberculosis-programme/treatment

TB burden driver

• Global TB burden is tracked by WHO Global TB Reports; procurement and program budgets scale with the number of people treated and diagnosed. (See sources.)
  • WHO Global TB Report hub: https://www.who.int/teams/global-tuberculosis-programme/tb-reports

Market projection: what trajectory should investors expect?

Base case structure

• Growth driver: rising treatment volume in high-burden settings and continued global procurement.
• Constraint: pricing pressure from generics, and regimen shifts that can increase use of rifamycin-based combinations with shorter or different dosing structures, potentially reducing demand share of specific pairings.
• Regimen migration risk: TB programs increasingly adopt fixed-dose combination packs and modern regimen logic. That shifts “pair-market” demand toward combination products and may reduce the share of “rifampin + isoniazid” sold as separate components in some tenders.

Outcome for rifampin + isoniazid specifically

• The combination’s overall demand should track isoniazid plus rifamycin regimen inclusion rather than expecting a standalone product category surge.
• Near-term upside typically comes from:
  • procurement expansions tied to case detection and program catch-up
  • improved adherence products (fixed-dose combinations or co-pack formulations)
• Downside typically comes from:
  • procurement switching to alternative formulations and pack architectures
  • commoditization pressure across generic suppliers

What clinical endpoints and regulatory considerations control commercial differentiation?

Even where efficacy is “known,” trials and regulatory strategy revolve around endpoints and label-relevant safety:

Common clinical endpoints

• PK exposure: AUC, Cmax, steady-state attainment
• Safety/tolerability: hepatotoxicity markers (ALT/AST elevations), hypersensitivity, GI tolerability
• Adherence proxies: pill burden, treatment completion, missed-dose patterns
• Treatment response markers: sputum conversion (where applicable), time to culture negativity (trial-dependent)

Regulatory and labeling considerations

• Rifampin and isoniazid have classic safety concerns, especially:
  • hepatotoxicity risk and drug-drug interaction constraints (rifampin is a strong enzyme inducer)
  • monitoring requirements in populations with liver risk
• For fixed-dose combinations or co-packaged products, regulatory differentiation often hinges on:
  • bioequivalence and exposure matching
  • updated dosing schedules aligned to modern guidelines

Where do patents and exclusivity typically matter for this combination?

For business planning, the key point is that rifampin and isoniazid are long-established generics in most jurisdictions. Practical patent leverage often appears in one of four buckets:

1. New fixed-dose combination patents (composition-of-matter around a specific combination format)
2. New dosing regimens (method-of-use claims tied to specific schedules and populations)
3. Formulation patents (e.g., controlled release or improved stability)
4. Second-generation clinical data packages that support label updates (often not patentable themselves, but can support lifecycle management)

Patent strength is jurisdiction-specific and claim-dependent; broad substance claims are generally not available for these established actives.

Competitive landscape: what products compete with rifampin + isoniazid?

Competition typically occurs in:

• Generic rifampin and isoniazid tablets (separate or co-packaged)
• Fixed-dose combination TB packs
  • Regimens frequently use multi-drug FDC products that include rifamycins plus companion agents; isoniazid may be part of multi-agent fixed-dose structures even when not sold as a pure “rifampin + isoniazid” product line.
• Alternative regimens for latent TB
  • Regimens using rifamycin-containing combinations can compete with isoniazid-centric protocols, depending on the health system and guideline adoption.

Commercial projection by scenario

Because the category is anchored in TB programs and procurement, scenario modeling should focus on program volume and procurement pack architecture rather than advertising or uptake-driven demand.

1) Base case (program-driven growth)

• TB treatment volume continues to rise with improved detection and sustained funding.
• Share of patients on isoniazid-containing regimens remains stable.
• Rifampin inclusion stays high in drug-susceptible strategies.

2) Upside case (procurement acceleration and FDC substitution)

• Expansion of TB case detection and intensified program spending increases patient starts.
• Increased adoption of fixed-dose combinations that preserve rifampin plus isoniazid dosing in multi-drug packs increases the accessible “rifampin + isoniazid exposure” volume.

3) Downside case (pack migration away from older pairing architectures)

• Health systems increasingly switch to alternative regimen pack designs.
• Separate-component purchasing declines in favor of multi-drug FDC architectures that dilute the measurable “pair” market.

What should executives watch over the next 24 months?

1. WHO guideline updates and module revisions affecting regimen composition or duration.
2. ClinicalTrials.gov activity for regimen optimization studies that include both actives and report exposure or safety outcomes.
3. Public procurement signals in high-burden countries indicating movement toward specific FDC pack structures.

Key Takeaways

• Rifampin plus isoniazid remains a core regimen component in drug-susceptible TB and isoniazid-centric strategies across many programs; the market is program-driven, not innovation-driven.
• Clinical trials are likely to emphasize regimen optimization, PK, and safety, especially in high-risk populations and under modern guideline constraints.
• Market growth should track TB patient starts and isoniazid regimen inclusion, with commercial share shaped by procurement and fixed-dose pack architecture more than by standalone “pair product” demand.
• Patent leverage is typically limited to format, formulation, or method-of-use claims rather than to original actives; competitive pressure is usually generic and tender-based.

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FAQs

1) Is there still meaningful clinical trial activity for rifampin plus isoniazid?

Yes. Trial registrations typically focus on regimen strategy, population safety, and PK/exposure endpoints rather than proving foundational efficacy.

2) Does demand depend more on TB incidence or on pricing?

Both matter, but volumes driven by TB incidence and case detection usually determine the upper bound; pricing and tender competition determine realizable revenue.

3) What differentiates one product from another in this category?

Bioequivalence, formulation stability, pill burden/FDC integration, and label-relevant safety evidence in specific populations.

4) How should investors forecast “market size” for this combination?

Forecast TB-treated-patient volume and apply regimen inclusion shares for isoniazid and rifampin, then adjust for local procurement pack structures and price erosion.

5) Where do regulatory risks concentrate?

Hepatotoxicity monitoring expectations and rifampin’s interaction profile (enzyme induction) drive label constraints and clinical monitoring requirements.

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References

[1] World Health Organization. Global tuberculosis report. https://www.who.int/teams/global-tuberculosis-programme/tb-reports
[2] World Health Organization. Tuberculosis treatment (guidelines and recommendations). https://www.who.int/teams/global-tuberculosis-programme/treatment
[3] ClinicalTrials.gov. https://clinicaltrials.gov/
[4] World Health Organization. WHO International Clinical Trials Registry Platform (ICTRP): TrialSearch. https://trialsearch.who.int/