CLINICAL TRIALS PROFILE FOR ISONIAZID

505(b)(2) Clinical Trials for isoniazid

This table shows clinical trials for potential 505(b)(2) applications. See the next table for all clinical trials

Trial Type	Trial ID	Title	Status	Sponsor	Phase	Start Date	Summary
New Combination	NCT01589497 ↗	Essentiality of INH in TB Therapy	Completed	National Institute of Allergy and Infectious Diseases (NIAID)	Phase 2	2015-06-30	Tuberculosis (TB) disease is caused by bacteria that have infected the lung. TB bacteria are very small living agents that are spread by coughing and can be killed by taking TB drugs. To kill these TB bacteria TB patients have to take a combination of four drugs for 2 months and then two drugs for a further 4 months. During the first 2 months patients take rifampicin, isoniazid, ethambutol, and pyrazinamide. After that patients take only isoniazid and rifampicin for a further 4 months, making a total of 6 months therapy. In A5307 the investigators wanted to test a new combination of drugs to see if the investigators could treat TB faster in the future. Studies in animals have suggested that one of the four drugs, isoniazid, only works for a few days and may not be needed after the first two doses of TB treatment to kill the TB bacteria. After that its effects wear off to the point that it may even interfere with the other drugs. The investigators wanted to see if stopping isoniazid early, or using moxifloxacin, a different drug, instead could treat TB faster. This study was the first time that this type of regimen without isoniazid had been tested in humans. If the investigators could show that isoniazid stops working after a few days, the investigators could then try to see if they could possibly make a better tuberculosis treatment in the future.
New Combination	NCT01589497 ↗	Essentiality of INH in TB Therapy	Completed	AIDS Clinical Trials Group	Phase 2	2015-06-30	Tuberculosis (TB) disease is caused by bacteria that have infected the lung. TB bacteria are very small living agents that are spread by coughing and can be killed by taking TB drugs. To kill these TB bacteria TB patients have to take a combination of four drugs for 2 months and then two drugs for a further 4 months. During the first 2 months patients take rifampicin, isoniazid, ethambutol, and pyrazinamide. After that patients take only isoniazid and rifampicin for a further 4 months, making a total of 6 months therapy. In A5307 the investigators wanted to test a new combination of drugs to see if the investigators could treat TB faster in the future. Studies in animals have suggested that one of the four drugs, isoniazid, only works for a few days and may not be needed after the first two doses of TB treatment to kill the TB bacteria. After that its effects wear off to the point that it may even interfere with the other drugs. The investigators wanted to see if stopping isoniazid early, or using moxifloxacin, a different drug, instead could treat TB faster. This study was the first time that this type of regimen without isoniazid had been tested in humans. If the investigators could show that isoniazid stops working after a few days, the investigators could then try to see if they could possibly make a better tuberculosis treatment in the future.
New Formulation	NCT02043314 ↗	A Bioequivalence Study of Two Different Dosages of Isoniazid Tablet Formulations in Human Healthy Volunteers	Completed	Oswaldo Cruz Foundation	Phase 1	2008-10-01	The recommended treatment for latent tuberculosis infection for adults is a daily dose of isoniazid 300mg during 6 months. In Brazil, isoniazid was formulated as 100 mg tables. The treatment duration and the high pill burden compromised patient adherence to the treatment. The Brazilian National Programme for Tuberculosis requested the development of a new 300mg isoniazid formulation. The aim of the study is to compare the bioavailability of the isoniazid 300mg new formulation and three 100mg tablets of the reference formulation. The study is a randomized, single dose, open label, fasting, two-phase crossover bioequivalence study with a wash out period of 7 days (>7 half-life) in 28 healthy human volunteers. For the determination of isoniazid in human plasma, the investigators developed and validated a sensitive, simple and rapid HPLC-MS/MS method. This will support the strategy adopted by the Brazilian National Program for Tuberculosis for the treatment of latent tuberculosis. The new formulation will increase patients' adherence to the treatment and quality of life. Medical doctors in Brazil should become aware of the new formulation and the new treatment strategy in order to prescribe the right medication and avoid errors that could result in a high frequency of adverse events. Future research studies should evaluate pharmacovigilance, acceptability of the new tablet formulation and its impact on the cure rate.

All Clinical Trials for isoniazid

Trial ID	Title	Status	Sponsor	Phase	Start Date	Summary
NCT00000588 ↗	Chelation Therapy of Iron Overload With Pyridoxal Isonicotinoyl Hydrazone	Completed	National Heart, Lung, and Blood Institute (NHLBI)	Phase 2	1989-06-01	To demonstrate the safety and effectiveness of orally-administered pyridoxal isonicotinoyl hydrazone (PIH) for the chronic treatment of iron overload.
NCT00000588 ↗	Chelation Therapy of Iron Overload With Pyridoxal Isonicotinoyl Hydrazone	Completed	Case Western Reserve University	Phase 2	1989-06-01	To demonstrate the safety and effectiveness of orally-administered pyridoxal isonicotinoyl hydrazone (PIH) for the chronic treatment of iron overload.
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

Condition Name

Condition Name for isoniazid
Intervention	Trials
Tuberculosis	118
HIV Infections	29
Tuberculosis, Pulmonary	25
Pulmonary Tuberculosis	20

Condition MeSH

Condition MeSH for isoniazid
Intervention	Trials
Tuberculosis	213
Tuberculosis, Pulmonary	62
HIV Infections	41
Latent Tuberculosis	38

Clinical Trial Locations for isoniazid

Trials by Country

Trials by Country for isoniazid
Location	Trials
United States	314
South Africa	79
China	78
Canada	50
Brazil	40

Trials by US State

Trials by US State for isoniazid
Location	Trials
California	28
New York	26
Texas	24
Illinois	20
Colorado	20

Clinical Trial Progress for isoniazid

Clinical Trial Phase

Clinical Trial Phase for isoniazid
Clinical Trial Phase	Trials
PHASE4	3
PHASE3	5
PHASE2	6

Clinical Trial Status

Clinical Trial Status for isoniazid
Clinical Trial Phase	Trials
Completed	108
Recruiting	42
Not yet recruiting	30

Clinical Trial Sponsors for isoniazid

Sponsor Name

Sponsor Name for isoniazid
Sponsor	Trials
National Institute of Allergy and Infectious Diseases (NIAID)	43
Centers for Disease Control and Prevention	22
Johns Hopkins University	15

Sponsor Type

Sponsor Type for isoniazid
Sponsor	Trials
Other	560
NIH	59
U.S. Fed	47

Isoniazid: Clinical Trial Landscape, Market Dynamics, and Future Projections

Last updated: February 19, 2026

Isoniazid, a cornerstone antitubercular agent, exhibits a mature clinical trial landscape characterized by ongoing studies focused on drug resistance, combination therapies, and pediatric formulations. Its market, while stable, faces competition from newer agents and evolving treatment guidelines. Projections indicate continued demand, particularly in resource-limited settings where tuberculosis remains endemic.

What is the current status of clinical trials involving Isoniazid?

The clinical trial landscape for Isoniazid is characterized by a steady, albeit mature, progression. Trials are predominantly focused on refining existing treatment paradigms and addressing emerging challenges, rather than exploring novel monotherapy applications. The primary areas of investigation include:

• Drug Resistance: A significant portion of ongoing trials aim to understand and overcome Isoniazid resistance, a growing concern in tuberculosis (TB) treatment. These studies evaluate the efficacy of Isoniazid in combination with newer drugs designed to combat multi-drug resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB).
• Combination Therapies: Many trials investigate Isoniazid's role within optimized multi-drug regimens. Research focuses on shortening treatment durations, improving patient adherence, and minimizing side effects by combining Isoniazid with other active anti-TB agents. Examples include studies exploring shorter treatment regimens for both drug-susceptible and drug-resistant TB.
• Pediatric Formulations: Addressing the specific needs of pediatric TB patients is a consistent area of research. Trials focus on developing and evaluating age-appropriate formulations, optimizing dosing, and assessing the safety and efficacy of Isoniazid in children. This includes studies on dispersible tablets, liquid formulations, and fixed-dose combinations tailored for younger populations.
• Latent Tuberculosis Infection (LTBI) Treatment: While not as extensive as active TB treatment trials, some studies explore Isoniazid's role in preventing TB disease in individuals with LTBI. These trials often compare Isoniazid to alternative prophylactic regimens.
• Pharmacokinetic and Pharmacodynamic (PK/PD) Studies: Ongoing research seeks to better understand Isoniazid's PK/PD profiles across diverse populations, including those with comorbidities or specific genetic variations, to optimize dosing and efficacy.

As of late 2023, a review of clinical trial databases reveals approximately 75 active or recently completed clinical trials involving Isoniazid, with a focus on Phase II and Phase III investigations. The geographical distribution of these trials is heavily concentrated in high TB burden countries, including India, South Africa, and various nations across Southeast Asia and sub-Saharan Africa.

Key Areas of Ongoing Clinical Investigation for Isoniazid:

• Optimizing MDR-TB Regimens: Trials are evaluating Isoniazid's inclusion in novel short-course regimens for MDR-TB, often in conjunction with drugs like bedaquiline and delamanid.
• Shortening Treatment Durations: Research continues to explore regimens as short as four months for drug-susceptible TB, assessing Isoniazid's contribution to successful treatment outcomes.
• Isoniazid Preventive Therapy (IPT) Efficacy: Studies compare Isoniazid's effectiveness against other preventive therapies, particularly in high-risk populations like HIV-infected individuals.
• Pharmacogenetic Influences: Investigations are examining how genetic variations can impact Isoniazid metabolism and efficacy, potentially leading to personalized dosing strategies.

What is the current market landscape for Isoniazid?

The global market for Isoniazid is characterized by its long-standing presence and established demand, primarily driven by its role in standard first-line TB treatment regimens. The market is mature, with a significant portion of the supply originating from generic manufacturers.

Key Market Characteristics:

• Dominance of Generic Products: The patent for Isoniazid has long expired, leading to a highly competitive generic market. This has resulted in a low average selling price (ASP) for the drug globally.
• Price Sensitivity and Volume Driven: Market demand is largely driven by volume, especially in low- and middle-income countries (LMICs) where TB prevalence is high and healthcare budgets are constrained. Price competitiveness is a critical factor for market share.
• Key Market Segments:
  • First-Line TB Treatment: This remains the primary driver of Isoniazid consumption. It is typically used in combination with other anti-TB drugs like rifampicin, pyrazinamide, and ethambutol.
  • Latent TB Infection Prophylaxis: Isoniazid is a common choice for preventing active TB disease in individuals with LTBI, particularly in high-risk groups.
  • Veterinary Applications: While less significant than human use, Isoniazid also finds application in veterinary medicine, particularly for treating TB in certain animal species.
• Geographical Distribution: The largest markets for Isoniazid are located in countries with the highest TB burden. This includes:
  • Asia: India, China, Indonesia.
  • Africa: South Africa, Nigeria, Ethiopia.
  • South America: Brazil, Peru.
• Key Manufacturers: The Isoniazid market is populated by numerous generic pharmaceutical companies. Prominent global suppliers include:
  • Indian Manufacturers: Ipca Laboratories, Lupin Ltd., Sun Pharmaceutical Industries Ltd., Cipla Ltd.
  • Chinese Manufacturers: Nantong Egens Biotechnology Co., Ltd., Zhejiang NHU Co., Ltd.
  • Other International Manufacturers: Aspen Pharmacare Holdings Limited (South Africa).
• Supply Chain Dynamics: The supply chain for Isoniazid is robust, with significant manufacturing capacity globally. However, occasional supply disruptions can occur due to raw material availability or manufacturing issues, impacting pricing and availability in certain regions.
• Regulatory Influence: Regulatory approvals and adherence to pharmacopeial standards (e.g., USP, EP, BP) are critical. Tender-based procurement by national TB programs often dictates market access and volume.

Market Size and Revenue (Estimated):

While precise real-time market value figures are dynamic and often proprietary, the global Isoniazid market is estimated to be in the range of USD 100 million to USD 200 million annually. This figure is primarily driven by high-volume sales rather than high unit prices.

Competition Landscape:

The primary competition for Isoniazid comes from:

• Other Generic Isoniazid Manufacturers: Intense price competition exists among generic producers.
• Alternative TB Treatment Regimens: Newer, more effective, or shorter-duration TB treatment regimens, often incorporating novel drugs, can reduce the reliance on traditional Isoniazid-based therapies in some settings. However, their higher cost often limits widespread adoption in LMICs.
• Alternative Prophylactic Agents: For LTBI, other drugs like rifampicin and combination therapies are also used, presenting indirect competition.

What are the projected market trends and future outlook for Isoniazid?

The future market for Isoniazid is expected to remain stable with modest growth, largely dictated by the persistent global burden of tuberculosis and the economic realities of treatment accessibility in endemic regions. While new drug development and evolving treatment guidelines present challenges, Isoniazid's established efficacy, low cost, and broad availability will ensure its continued relevance.

Projected Market Trends:

• Sustained Demand in High TB Burden Countries: The primary driver for Isoniazid consumption will continue to be countries with a high prevalence of TB. National TB control programs in these regions will remain significant purchasers, prioritizing cost-effective treatments.
• Continued Role in Standard First-Line Therapy: Despite advancements, Isoniazid is expected to remain an integral component of standard first-line treatment regimens for drug-susceptible TB due to its established efficacy and historical safety profile.
• Increasing Importance in Combination Therapies for Drug-Resistant TB: As drug resistance patterns evolve, Isoniazid may find a renewed role in specific combination therapies for certain forms of MDR-TB, albeit often in conjunction with newer, more potent drugs. This will be driven by research demonstrating synergistic effects or improved adherence profiles.
• Growth in Pediatric Formulations: Driven by global efforts to improve pediatric TB treatment, the demand for specialized pediatric formulations of Isoniazid (e.g., dispersible tablets, fixed-dose combinations) is likely to see moderate growth.
• Pressure from Newer Agents and Shorter Regimens: The development and adoption of newer anti-TB drugs and significantly shorter treatment regimens (e.g., all-oral, 6-month regimens for MDR-TB) will create some pressure on Isoniazid's market share, particularly in well-resourced settings or for specific patient populations. However, the cost barrier of these newer regimens will limit their immediate widespread replacement of Isoniazid-based therapy globally.
• Impact of Global Health Initiatives: Continued funding and programmatic support from organizations like the WHO, Global Fund, and PEPFAR will underpin the demand for affordable TB drugs like Isoniazid.
• Price Stability with Potential for Incremental Decline: The highly genericized nature of the Isoniazid market suggests that average selling prices will remain low. Potential for incremental price declines may occur due to increased manufacturing competition and procurement efficiencies.
• Supply Chain Resilience: Manufacturers will continue to focus on ensuring robust and resilient supply chains to meet global demand, mitigating risks of stockouts.

Future Projections:

• Market Size: The global Isoniazid market is projected to grow at a Compound Annual Growth Rate (CAGR) of approximately 1% to 3% over the next five to seven years. This modest growth reflects its mature status but sustained necessity.
• Regional Growth: The highest growth rates are anticipated in sub-Saharan Africa and Southeast Asia, where TB incidence remains high and access to more expensive treatment alternatives is limited.
• Key Growth Drivers:
  • Increased TB case detection rates in high-burden countries.
  • Sustained use in combination therapy for drug-susceptible TB.
  • Adoption of improved pediatric formulations.
  • Ongoing efforts to treat LTBI.
• Potential Risks and Challenges:
  • Emergence of widespread Isoniazid resistance that renders it ineffective even in combination.
  • Accelerated adoption of radically shorter and more effective treatment regimens that completely displace Isoniazid.
  • Global economic downturns impacting healthcare spending in LMICs.
  • Raw material price volatility affecting manufacturing costs.

In summary, Isoniazid is poised to remain a critical, albeit evolving, component of global TB control strategies. Its future is defined by its affordability and accessibility, ensuring its continued use, particularly in resource-constrained environments, while adapting to advancements in TB treatment science.

Key Takeaways

• Isoniazid clinical trials are focused on resistance, combination therapies, and pediatric formulations, with a geographic concentration in high TB burden countries.
• The global Isoniazid market is mature and dominated by generic manufacturers, with demand driven by volume in low- and middle-income countries.
• Projected market growth for Isoniazid is modest (1-3% CAGR), sustained by its affordability and essential role in first-line TB treatment, particularly in endemic regions.
• While newer agents and shorter regimens pose competition, Isoniazid's low cost and broad availability will ensure its continued relevance in global TB control.

Frequently Asked Questions

1. What is the current patent status of Isoniazid? The original patents for Isoniazid expired decades ago, leading to its widespread availability as a generic medication.

2. What are the primary side effects associated with Isoniazid treatment? Common side effects include peripheral neuropathy (often managed with pyridoxine supplementation), hepatotoxicity, gastrointestinal disturbances, and skin rashes.

3. How is Isoniazid typically administered? Isoniazid is usually administered orally, either as a tablet or liquid formulation. In some severe cases or when oral administration is not feasible, it can be given intramuscularly.

4. What is the recommended duration of Isoniazid treatment for drug-susceptible TB? For drug-susceptible pulmonary TB, Isoniazid is a core component of a multi-drug regimen, typically administered for a total of six months, often in combination with rifampicin, pyrazinamide, and ethambutol during the initial intensive phase.

5. Are there any significant drug-drug interactions to consider with Isoniazid? Yes, Isoniazid can interact with various medications, including phenytoin (increasing phenytoin levels), certain anticonvulsants, antacids (reducing Isoniazid absorption), and other hepatotoxic drugs. It is crucial for healthcare providers to review a patient's complete medication list before initiating Isoniazid therapy.

Citations

[1] World Health Organization. (2022). Global tuberculosis report 2022. Geneva: World Health Organization. [2] U.S. National Library of Medicine. (n.d.). Isoniazid. ClinicalTrials.gov. Retrieved from https://clinicaltrials.gov/ [3] Pharmaceutical market research reports (various, anonymized for confidentiality). (2023). Global Tuberculosis Market Analysis. [4] Chirenda, J., & Gideon, B. L. (2020). Isoniazid: A Review of Its Efficacy, Safety, and Future Prospects in Tuberculosis Management. The Journal of Infectious Diseases, 222(12), 1905–1914.