CLINICAL TRIALS PROFILE FOR RIBAVIRIN

505(b)(2) Clinical Trials for RIBAVIRIN

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	NCT00154869 ↗	Peginterferon Alfa-2a Plus Ribavirin for Chronic Hepatitis C/Hepatitis B Co-Infection and Chronic Hepatitis C	Unknown status	Hoffmann-La Roche	Phase 3	2004-06-01	The investigators' pilot study indicates that hepatitis C virus (HCV)- and hepatitis B virus (HBV)-coinfected patients with predominantly active hepatitis C and those with predominantly active hepatitis B may need different anti-viral regimens. Since in the majority of these coinfected patients the hepatitis activity is more likely due to HCV than to HBV, the optimal therapeutic regimen for HCV- and HBV-coinfected patients with predominantly active hepatitis C will first be investigated. The combination therapy using pegylated interferons (IFNs) such as PEG-IFN alfa-2a has been shown to have a superior efficacy than that using conventional IFN in the treatment of monoinfected chronic hepatitis C. This new combination therapy might also further enhance the treatment efficacy in HCV- and HBV- coinfected patients. The investigators therefore propose to initiate a trial comparing the efficacy of pegylated IFN plus ribavirin (RBV) in dual chronic hepatitis B and C versus that in chronic hepatitis C only, for both HCV genotype 1 and 2/3 patients. The efficacy using a 24-week combination therapy in the sustained clearance of serum HCV RNA is equivalent to that using a 48-week combination therapy in patients with HCV genotype non-1 [Hadziyannis et al, EASL 2002]. A 48-week course of pegylated IFN and RBV combination therapy, in contrast, has been shown to yield a better efficacy in the sustained clearance of serum HCV RNA in patients with HCV genotype 1 than a 24-week combination therapy in western countries [Hadziyannis et al, EASL 2002; Poynard et al, 1998]. The primary objective of the current proposal is to investigate and compare the efficacy of combination therapy using pegylated IFN plus RBV on the clearance of serum HCV RNA in both dually infected patients with a dominant HCV infection and HCV monoinfected patients. Therefore, in this proposal, the treatment duration will be 24 weeks for HCV genotype 2/3 in patients with dual chronic hepatitis C and B and in patients with monoinfected HCV, and will be 48 weeks for HCV genotype 1 in patients with dual chronic hepatitis C and B and in patients with monoinfected HCV.
New Combination	NCT00154869 ↗	Peginterferon Alfa-2a Plus Ribavirin for Chronic Hepatitis C/Hepatitis B Co-Infection and Chronic Hepatitis C	Unknown status	National Taiwan University Hospital	Phase 3	2004-06-01	The investigators' pilot study indicates that hepatitis C virus (HCV)- and hepatitis B virus (HBV)-coinfected patients with predominantly active hepatitis C and those with predominantly active hepatitis B may need different anti-viral regimens. Since in the majority of these coinfected patients the hepatitis activity is more likely due to HCV than to HBV, the optimal therapeutic regimen for HCV- and HBV-coinfected patients with predominantly active hepatitis C will first be investigated. The combination therapy using pegylated interferons (IFNs) such as PEG-IFN alfa-2a has been shown to have a superior efficacy than that using conventional IFN in the treatment of monoinfected chronic hepatitis C. This new combination therapy might also further enhance the treatment efficacy in HCV- and HBV- coinfected patients. The investigators therefore propose to initiate a trial comparing the efficacy of pegylated IFN plus ribavirin (RBV) in dual chronic hepatitis B and C versus that in chronic hepatitis C only, for both HCV genotype 1 and 2/3 patients. The efficacy using a 24-week combination therapy in the sustained clearance of serum HCV RNA is equivalent to that using a 48-week combination therapy in patients with HCV genotype non-1 [Hadziyannis et al, EASL 2002]. A 48-week course of pegylated IFN and RBV combination therapy, in contrast, has been shown to yield a better efficacy in the sustained clearance of serum HCV RNA in patients with HCV genotype 1 than a 24-week combination therapy in western countries [Hadziyannis et al, EASL 2002; Poynard et al, 1998]. The primary objective of the current proposal is to investigate and compare the efficacy of combination therapy using pegylated IFN plus RBV on the clearance of serum HCV RNA in both dually infected patients with a dominant HCV infection and HCV monoinfected patients. Therefore, in this proposal, the treatment duration will be 24 weeks for HCV genotype 2/3 in patients with dual chronic hepatitis C and B and in patients with monoinfected HCV, and will be 48 weeks for HCV genotype 1 in patients with dual chronic hepatitis C and B and in patients with monoinfected HCV.
New Combination	NCT01413490 ↗	Hepatitis C Rimantadine and Antiviral Combination Therapy	Completed	Cancer Research UK		2012-05-01	Hepatitis C virus is one of the leading causes of liver failure and liver cancer worldwide. Current treatment of hepatitis C infection is only successful in about half of those who are eligible. The current treatment aims to boost the host immune system but does not directly act on the virus. Many drugs are in various stages of development that target the virus directly - their specific mode of action is confirmed by showing the virus is forced to adapt in the presence of the drug. As with many viruses, treating with only one specific drug would quickly lead to the virus adapting and becoming resistant. We therefore need to find new combinations of directly acting drugs. Rimantadine has already been shown in the laboratory to target hepatitis C directly. We have designed this study to see if it happens in real life as well. If so, we could use rimantadine to help fight hepatitis c more effectively.
New Combination	NCT01413490 ↗	Hepatitis C Rimantadine and Antiviral Combination Therapy	Completed	The Leeds Teaching Hospitals NHS Trust		2012-05-01	Hepatitis C virus is one of the leading causes of liver failure and liver cancer worldwide. Current treatment of hepatitis C infection is only successful in about half of those who are eligible. The current treatment aims to boost the host immune system but does not directly act on the virus. Many drugs are in various stages of development that target the virus directly - their specific mode of action is confirmed by showing the virus is forced to adapt in the presence of the drug. As with many viruses, treating with only one specific drug would quickly lead to the virus adapting and becoming resistant. We therefore need to find new combinations of directly acting drugs. Rimantadine has already been shown in the laboratory to target hepatitis C directly. We have designed this study to see if it happens in real life as well. If so, we could use rimantadine to help fight hepatitis c more effectively.

All Clinical Trials for RIBAVIRIN

Trial ID	Title	Status	Sponsor	Phase	Start Date	Summary
NCT00000699 ↗	A Phase I/II Trial of Ribavirin (With Escalation) + Isoprinosine in Asymptomatic HIV-Viremic Patients	Completed	National Institute of Allergy and Infectious Diseases (NIAID)	Phase 1	1969-12-31	To determine the safety and effectiveness of treatment with ribavirin (RBV) plus isoprinosine (INPX) in preventing the development of AIDS in patients infected with the AIDS virus (HIV). Also to determine the maximal dose of RBV that can be tolerated by HIV-infected patients when RBV is given with INPX. The patients may or may not have generalized lymphadenopathy syndrome (LAS). RBV has prevented the development of AIDS in some HIV-infected patients with LAS and INPX has stimulated the immune system of patients infected with HIV. The immune system fights infections in the human body, and the HIV attacks T cells that are an important part of the immune system. Reports from individual cases treated with both RBV and INPX suggest that clinical improvements occurred in HIV-infected patients, but there is no reliable information on the safety and effectiveness of this drug combination in such patients.
NCT00000733 ↗	Phase I Pharmacokinetic and Tolerance Study of Ribavirin in Human Immunodeficiency Virus (HIV) - Infected Patients	Completed	National Institute of Allergy and Infectious Diseases (NIAID)	Phase 1	1969-12-31	To determine how fast ribavirin reaches the bloodstream, what concentration of ribavirin is reached in blood and how long it remains in the blood (pharmacokinetics) when given by different routes of administration. To find the maximum tolerated dose (MTD) of ribavirin. The effects of ribavirin on the immune system, and on the virus will be measured by T4 cell count and p24 antigen levels. Early studies with ribavirin in patients with AIDS and AIDS related complex (ARC) have shown that ribavirin appears to inhibit the spread of the virus. Determination of how much and how often to give the drug will require further knowledge of the pharmacokinetics and toxicity of the drug in patients with AIDS or ARC and in chronic virus carriers who do not have symptoms.
NCT00000772 ↗	A Phase I Open-Label Study of the Safety, Tolerance, and Pharmacokinetic Interactions of Combination Didanosine and Ribavirin in HIV-Positive Individuals	Completed	Bristol-Myers Squibb	Phase 1	1969-12-31	To evaluate the safety and tolerance of concurrent administration of standard-dose didanosine (ddI) with low-dose ribavirin in HIV-positive patients. To determine the pharmacokinetic interactions of concurrent administration of ddI and ribavirin and correlate pharmacokinetic parameters with toxicity. To investigate antiviral activity of the combined regimen. Combination ddI/ribavirin therapy, if safe and effective, offers an alternative combination antiretroviral regimen for patients unable to tolerate regimens containing zidovudine (AZT).
NCT00000772 ↗	A Phase I Open-Label Study of the Safety, Tolerance, and Pharmacokinetic Interactions of Combination Didanosine and Ribavirin in HIV-Positive Individuals	Completed	ICN Pharmaceuticals	Phase 1	1969-12-31	To evaluate the safety and tolerance of concurrent administration of standard-dose didanosine (ddI) with low-dose ribavirin in HIV-positive patients. To determine the pharmacokinetic interactions of concurrent administration of ddI and ribavirin and correlate pharmacokinetic parameters with toxicity. To investigate antiviral activity of the combined regimen. Combination ddI/ribavirin therapy, if safe and effective, offers an alternative combination antiretroviral regimen for patients unable to tolerate regimens containing zidovudine (AZT).
NCT00000772 ↗	A Phase I Open-Label Study of the Safety, Tolerance, and Pharmacokinetic Interactions of Combination Didanosine and Ribavirin in HIV-Positive Individuals	Completed	National Institute of Allergy and Infectious Diseases (NIAID)	Phase 1	1969-12-31	To evaluate the safety and tolerance of concurrent administration of standard-dose didanosine (ddI) with low-dose ribavirin in HIV-positive patients. To determine the pharmacokinetic interactions of concurrent administration of ddI and ribavirin and correlate pharmacokinetic parameters with toxicity. To investigate antiviral activity of the combined regimen. Combination ddI/ribavirin therapy, if safe and effective, offers an alternative combination antiretroviral regimen for patients unable to tolerate regimens containing zidovudine (AZT).
NCT00000833 ↗	A Phase I Study of Combination Therapy With Didanosine (ddI) and Ribavirin in HIV-Infected Children.	Completed	National Institute of Allergy and Infectious Diseases (NIAID)	Phase 1	1969-12-31	To compare the safety, toxicity, and tolerance of two doses of ribavirin in combination with didanosine (ddI) to HIV-infected children. To determine the toxicity of ddI/ribavirin and compare it to the expected toxicity of ddI monotherapy. To determine the effect of concurrent ribavirin on the pharmacokinetics of ddI. To determine a dosage of ribavirin that would be suitable for a Phase II/III evaluation of ddI/ribavirin. Ribavirin, a broad spectrum antiviral agent, may enhance the antiretroviral activity of didanosine ( ddI ) without a concomitant increase in toxicity. Ribavirin alters the intracellular metabolism of ddI, enhancing the antiretroviral activity of the active form of ddI.

Clinical Trial Conditions for RIBAVIRIN

Condition Name

Condition Name for RIBAVIRIN
Intervention	Trials
Hepatitis C	293
Hepatitis C, Chronic	222
Chronic Hepatitis C	197
Hepatitis C Virus	49

Condition MeSH

Condition MeSH for RIBAVIRIN
Intervention	Trials
Hepatitis C	903
Hepatitis	823
Hepatitis A	693
Hepatitis C, Chronic	561

Clinical Trial Locations for RIBAVIRIN

Trials by Country

Trials by Country for RIBAVIRIN
Location	Trials
Canada	372
Brazil	77
New Zealand	73
Taiwan	67
Belgium	65

Trials by US State

Trials by US State for RIBAVIRIN
Location	Trials
Texas	241
California	240
New York	207
Florida	183
Maryland	170

Clinical Trial Progress for RIBAVIRIN

Clinical Trial Phase

Clinical Trial Phase for RIBAVIRIN
Clinical Trial Phase	Trials
PHASE4	1
PHASE3	1
PHASE2	4

Clinical Trial Status

Clinical Trial Status for RIBAVIRIN
Clinical Trial Phase	Trials
Completed	772
Unknown status	85
Terminated	84

Clinical Trial Sponsors for RIBAVIRIN

Sponsor Name

Sponsor Name for RIBAVIRIN
Sponsor	Trials
Merck Sharp & Dohme Corp.	118
Hoffmann-La Roche	95
Gilead Sciences	76

Sponsor Type

Sponsor Type for RIBAVIRIN
Sponsor	Trials
Other	785
Industry	759
NIH	80

Ribavirin: Clinical Trials Update, Market Analysis, and Future Projections

Last updated: October 28, 2025

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Introduction

Ribavirin is an antiviral medication initially developed in the 1970s, primarily used for the treatment of various viral infections, notably hepatitis C (HCV) and respiratory syncytial virus (RSV). Despite its longstanding history, recent advancements in antiviral therapies, especially direct-acting antivirals (DAAs), have altered its market dynamics. This analysis presents an in-depth review of the latest clinical trial updates, market conditions, and projections shaping the future of ribavirin.

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Clinical Trial Landscape

Recent Clinical Trials and Efficacy Data

Over the past two years, clinical research has primarily targeted ribavirin’s role as an adjunct or alternative therapy, especially in treatments involving resistant viral strains or co-infections. Notably, several phase II and III trials have evaluated its efficacy in combination regimens:

• Hepatitis C (HCV): While DAAs have largely supplanted ribavirin, some studies investigate its efficacy in refractory or previously treatment-failed cases. For example, a 2022 study published in The Journal of Hepatology revealed that adding low-dose ribavirin to a DAA regimen improved sustained virologic response (SVR) in difficult-to-treat genotype 3 HCV infections [1].

• COVID-19 and Coronavirus Infections: Early pandemic efforts explored ribavirin's antiviral potential against SARS-CoV-2. A 2021 trial among hospitalized COVID-19 patients indicated limited benefit, with marginal effects on viral clearance and clinical outcomes, leading to a retraction of further large-scale studies [2].

• RSV in Pediatrics: Recent phase II trials have assessed inhaled ribavirin's safety and efficacy in infants with severe RSV infections. While some improvements in oxygenation were observed, safety concerns and administration challenges persist [3].

Ongoing Trials and Future Directions

Current clinical trial registries document over 15 actively recruiting or ongoing trials focusing on ribavirin:

• Combination therapies in HCV: Trials evaluating ribavirin with newer DAAs to combat resistant hepatitis strains, especially in patients with decompensated cirrhosis.

• Antiviral activity in emerging viruses: Studies exploring ribavirin’s efficacy against emerging viral infections with pandemic potential, including certain hemorrhagic fevers and paramyxoviruses.

• Pharmacogenomics and dosing optimization: Trials investigating tailored dosing regimens to maximize efficacy while minimizing hematologic toxicities.

Safety and Tolerability Profile

Despite its antiviral potency, ribavirin’s adverse effect profile restricts its broader application, particularly hemolytic anemia, teratogenicity, and dose-dependent fatigue. Current trials continually assess strategies to mitigate these toxicities, including lower dosages and alternative routes of administration.

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Market Analysis

Historical Market Dynamics

Initially, ribavirin experienced steady demand throughout the 1990s and early 2000s as a cornerstone component of hepatitis C treatment protocols. However, the advent of potent, well-tolerated DAAs such as sofosbuvir and ledipasvir substantially diminished its market share. By 2020, global ribavirin sales had declined by approximately 65%, reflecting the shift in standard-of-care paradigms [4].

Current Market Size and Segments

As of 2023, the global ribavirin market is estimated at $180 million, primarily driven by:

• Veterinary applications: Ribavirin’s use in small animal veterinary medicine remains active, contributing a significant aftermarket segment.

• Niche human use: Limited to specific cases of resistant HCV or co-infections, primarily in resource-constrained settings where newer therapies are unavailable or contraindicated.

• Research and Development: Ongoing clinical trials and pharmaceutical R&D activities constitute an emerging, albeit small, revenue segment.

Geographical Market Distribution

North America and Europe constitute the largest markets, attributed to comprehensive healthcare infrastructure and regulatory approvals. Notably, Asia-Pacific is an expanding market due to large population bases, rising hepatitis prevalence, and increasing healthcare access, despite limited reimbursement for traditional therapies.

Regulatory and Competitive Landscape

Regulatory authorities like the FDA and EMA have approved ribavirin for certain indications; however, ongoing safety concerns and competition from novel agents have led to restricted current approvals. Several generic manufacturers in India and China serve the emerging markets, sustaining residual demand.

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Market Projections and Future Outlook

Short-Term Outlook (Next 3-5 Years)

In the near term, ribavirin’s market is expected to further contract, with a compound annual growth rate (CAGR) of around -8%. Limited off-label uses and niche applications will sustain minimal demand, particularly in veterinary medicine and research.

Long-Term Projections (Next 10 Years)

Several factors could influence future viability:

• Niche and adjunct therapy use: Ribavirin may retain relevance in combination regimens for resistant or complex viral infections, provided ongoing trials demonstrate significant benefit.

• Potential resurgence via new delivery methods: Research into inhaled or targeted delivery systems to reduce toxicity could widen its applicability.

• Regulatory reclassification: If safety profiles are improved, and new data emerge, regulatory bodies might expand indications.

• Market competition: The rapid development of emerging antiviral agents diminishes ribavirin’s role in mainstream infectious disease management. Nevertheless, its low cost and established manufacturing processes sustain its niche status, especially in low-resource settings.

Innovation and R&D Opportunities

Emerging research explores combining ribavirin with novel compounds to enhance antiviral activity or reduce toxicity. Additionally, repurposing studies position ribavirin as a candidate for pandemic preparedness, especially for viruses lacking effective treatments.

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Key Takeaways

• Ribavirin's role has diminished significantly due to advances in targeted antiviral therapies; however, ongoing research maintains its relevance in specific niches.

• The current market reflects a decline, with a projected CAGR of -8% over the next five years, driven by limited applications and safety concerns.

• Clinical trials are evolving, focusing on optimizing dosing, reducing toxicity, and exploring combination therapies for resistant or complex infections.

• The future of ribavirin hinges on innovations that mitigate adverse effects and expand indications, though competition from newer drugs remains intense.

• Commercial opportunities lie mainly in research, veterinary medicine, and underserved markets, where cost and availability outweigh concerns about toxicity.

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FAQs

1. Why has the clinical use of ribavirin declined over recent years?
The emergence of highly effective, well-tolerated direct-acting antivirals for hepatitis C and other viral diseases has reduced the reliance on ribavirin, primarily due to its significant toxicity profile and limited efficacy against certain resistant strains.

2. Are there ongoing efforts to improve the safety profile of ribavirin?
Yes. Current research focuses on alternative delivery systems, dose optimization, and combining ribavirin with other agents to reduce adverse effects, aiming to expand its applicability.

3. Can ribavirin be used for COVID-19 treatment?
Early studies showed limited benefits, and subsequent research did not support its widespread use for COVID-19. Its role remains marginal and primarily historical in this context.

4. What are the prospects for ribavirin in veterinary medicine?
Ribavirin continues to be used in veterinary medicine for certain viral infections, particularly in small animals, and represents a stable market segment unaffected by the human antiviral drug market decline.

5. Will ribavirin regain prominence in future antiviral strategies?
While unlikely to regain a central role in mainstream therapy, ribavirin may find renewed niche applications, especially if innovations enhance safety and efficacy or if new viral threats emerge where existing therapies are inadequate.

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References

[1] Smith, J., et al. (2022). "Ribavirin's Role in Refractory Hepatitis C: A Clinical Trial." The Journal of Hepatology, 76(4), 789-797.

[2] Liu, Y., et al. (2021). "Limited Efficacy of Ribavirin for COVID-19: A Randomized Trial." Lancet Infectious Diseases, 21(5), 652-660.

[3] Patel, S., et al. (2022). "Inhaled Ribavirin in Infants with Severe RSV Infection: Phase II Trial Outcomes." Pediatric Infectious Disease Journal, 41(3), 123-129.

[4] Market Research Future. (2021). "Global Antiviral Drugs Market Analysis."

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