CLINICAL TRIALS PROFILE FOR PEGINTERFERON ALFA-2A

All Clinical Trials for peginterferon alfa-2a

Trial ID	Title	Status	Sponsor	Phase	Start Date	Summary
NCT00001854 ↗	Long-Term Therapy With Ribavirin for Chronic Hepatitis C	Completed	National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)	Phase 4	1999-02-12	Chronic hepatitis C is a disease of the liver caused by the hepatitis C virus. The disease can be serious and even fatal. Approximately 25% of patients with chronic hepatitis C will develop cirrhosis and some of these patients will develop cancer of the liver or liver failure. Presently the disease is treated with a combination of alpha interferon or peginterferon (antiviral and immune stimulating drugs) and ribavirin (an antiviral drug). Alpha interferon is given by injection three times a week whereas peginterferon is given by injection only once a week. Ribavirin is given as a tablet by mouth twice a day. The combination therapy is given for 6 to months. About half of the patients given these medications will receive a lasting benefit and many patients do not respond well to the combination therapy. This study will select up to 50 patients will chronic hepatitis C who have not responded to combination therapy or who could not stand the side effects associated with interferon or peginterferon therapy. These subjects will be evaluated and undergo liver biopsy to determine their present liver condition. If selected as subjects they will be started on single drug therapy with ribavirin. The drug will be given orally twice a day at a dose based on the patient's body weight. The patients will be followed on an out-patient basis. They will we asked to return for regular check-ups and blood tests every 2 to 8 weeks for the duration of the study. After 6 months, the medication will be stopped or adjusted based on the results of the subject's blood tests (liver enzymes). A response is considered if a decrease of 50% or more of the initial liver enzyme (alanine aminotransferase, ALT) is noted. A complete response will be considered if liver enzymes return to normal levels. Therapy will be discontinued after 6 months if patients do not respond. However, patients that respond to the single drug therapy will continue to receive the medication at a decreased dose. The patients will remain on an appropriate dose for up to 8 years with repeat liver biopsies at 2, 4 and 8 years to assess progress. This study will determine if long-term therapy with ribavirin is safe and effective.
NCT00006164 ↗	Long Term Interferon for Patients Who Did Not Clear Hepatitis C Virus With Standard Treatment	Completed	Hoffmann-La Roche	Phase 3	2000-06-01	The HALT-C Trial is a National Institute of Diabetes and Digestive and Kidney Diseases sponsored, randomized clinical trial of long-term use of Peginterferon alfa-2a (pegylated interferon) in patients who failed to respond to prior interferon treatment. All patients who enter the trial will be treated for 6 months with Peginterferon alfa-2a and Ribavirin. Patients who respond to this 6 month treatment will continue to be treated for an additional 6 months. Patients who do not respond to this treatment will be eligible for the long-term maintenance phase of this study where patients will be randomly selected to be treated with Peginterferon alfa-2a or to discontinue treatment for 3.5 years. Patients in both arms of this study will be followed closely with quarterly study visits. The combination of peginterferon plus ribavirin has recently been approved by the FDA for treatment of chronic hepatitis C. Patients who remain HCV-RNA positive after being treated for at least 6 months with peginterferon and ribavirin outside of this study may be eligible to directly enter the randomized portion of the HALT-C Trial. The HALT-C study is designed to determine if continuing interferon long-term over several years will suppress Hepatitis C virus, prevent progression to cirrhosis, prevent liver cancer and reduce the need for liver transplantation.
NCT00006164 ↗	Long Term Interferon for Patients Who Did Not Clear Hepatitis C Virus With Standard Treatment	Completed	National Cancer Institute (NCI)	Phase 3	2000-06-01	The HALT-C Trial is a National Institute of Diabetes and Digestive and Kidney Diseases sponsored, randomized clinical trial of long-term use of Peginterferon alfa-2a (pegylated interferon) in patients who failed to respond to prior interferon treatment. All patients who enter the trial will be treated for 6 months with Peginterferon alfa-2a and Ribavirin. Patients who respond to this 6 month treatment will continue to be treated for an additional 6 months. Patients who do not respond to this treatment will be eligible for the long-term maintenance phase of this study where patients will be randomly selected to be treated with Peginterferon alfa-2a or to discontinue treatment for 3.5 years. Patients in both arms of this study will be followed closely with quarterly study visits. The combination of peginterferon plus ribavirin has recently been approved by the FDA for treatment of chronic hepatitis C. Patients who remain HCV-RNA positive after being treated for at least 6 months with peginterferon and ribavirin outside of this study may be eligible to directly enter the randomized portion of the HALT-C Trial. The HALT-C study is designed to determine if continuing interferon long-term over several years will suppress Hepatitis C virus, prevent progression to cirrhosis, prevent liver cancer and reduce the need for liver transplantation.
NCT00006164 ↗	Long Term Interferon for Patients Who Did Not Clear Hepatitis C Virus With Standard Treatment	Completed	National Institute of Allergy and Infectious Diseases (NIAID)	Phase 3	2000-06-01	The HALT-C Trial is a National Institute of Diabetes and Digestive and Kidney Diseases sponsored, randomized clinical trial of long-term use of Peginterferon alfa-2a (pegylated interferon) in patients who failed to respond to prior interferon treatment. All patients who enter the trial will be treated for 6 months with Peginterferon alfa-2a and Ribavirin. Patients who respond to this 6 month treatment will continue to be treated for an additional 6 months. Patients who do not respond to this treatment will be eligible for the long-term maintenance phase of this study where patients will be randomly selected to be treated with Peginterferon alfa-2a or to discontinue treatment for 3.5 years. Patients in both arms of this study will be followed closely with quarterly study visits. The combination of peginterferon plus ribavirin has recently been approved by the FDA for treatment of chronic hepatitis C. Patients who remain HCV-RNA positive after being treated for at least 6 months with peginterferon and ribavirin outside of this study may be eligible to directly enter the randomized portion of the HALT-C Trial. The HALT-C study is designed to determine if continuing interferon long-term over several years will suppress Hepatitis C virus, prevent progression to cirrhosis, prevent liver cancer and reduce the need for liver transplantation.
NCT00006164 ↗	Long Term Interferon for Patients Who Did Not Clear Hepatitis C Virus With Standard Treatment	Completed	National Institute on Minority Health and Health Disparities (NIMHD)	Phase 3	2000-06-01	The HALT-C Trial is a National Institute of Diabetes and Digestive and Kidney Diseases sponsored, randomized clinical trial of long-term use of Peginterferon alfa-2a (pegylated interferon) in patients who failed to respond to prior interferon treatment. All patients who enter the trial will be treated for 6 months with Peginterferon alfa-2a and Ribavirin. Patients who respond to this 6 month treatment will continue to be treated for an additional 6 months. Patients who do not respond to this treatment will be eligible for the long-term maintenance phase of this study where patients will be randomly selected to be treated with Peginterferon alfa-2a or to discontinue treatment for 3.5 years. Patients in both arms of this study will be followed closely with quarterly study visits. The combination of peginterferon plus ribavirin has recently been approved by the FDA for treatment of chronic hepatitis C. Patients who remain HCV-RNA positive after being treated for at least 6 months with peginterferon and ribavirin outside of this study may be eligible to directly enter the randomized portion of the HALT-C Trial. The HALT-C study is designed to determine if continuing interferon long-term over several years will suppress Hepatitis C virus, prevent progression to cirrhosis, prevent liver cancer and reduce the need for liver transplantation.

Clinical Trial Conditions for peginterferon alfa-2a

Condition Name

Condition Name for peginterferon alfa-2a
Intervention	Trials
Hepatitis C, Chronic	126
Hepatitis C	104
Chronic Hepatitis C	85
Chronic Hepatitis B	38

Condition MeSH

Condition MeSH for peginterferon alfa-2a
Intervention	Trials
Hepatitis	414
Hepatitis A	379
Hepatitis C	345
Hepatitis, Chronic	270

Clinical Trial Locations for peginterferon alfa-2a

Trials by Country

Trials by Country for peginterferon alfa-2a
Location	Trials
Canada	209
Italy	131
China	124
Germany	118
Australia	118

Trials by US State

Trials by US State for peginterferon alfa-2a
Location	Trials
California	110
Texas	100
New York	91
Florida	83
Maryland	83

Clinical Trial Progress for peginterferon alfa-2a

Clinical Trial Phase

Clinical Trial Phase for peginterferon alfa-2a
Clinical Trial Phase	Trials
PHASE4	1
PHASE3	1
PHASE2	1

Clinical Trial Status

Clinical Trial Status for peginterferon alfa-2a
Clinical Trial Phase	Trials
Completed	340
Terminated	48
Unknown status	47

Clinical Trial Sponsors for peginterferon alfa-2a

Sponsor Name

Sponsor Name for peginterferon alfa-2a
Sponsor	Trials
Hoffmann-La Roche	103
Merck Sharp & Dohme Corp.	52
Vertex Pharmaceuticals Incorporated	23

Sponsor Type

Sponsor Type for peginterferon alfa-2a
Sponsor	Trials
Other	379
Industry	367
NIH	37

Clinical Trials Update, Market Analysis, and Projection for Peginterferon Alfa-2a

Last updated: October 30, 2025

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Introduction

Peginterferon alfa-2a, a pegylated form of interferon alfa-2a, has long been a cornerstone in the treatment of chronic hepatitis C virus (HCV) infections and certain other viral illnesses. Its pharmacological properties, notably prolonged half-life and improved pharmacokinetics, have positioned it as a key therapeutic agent in viral hepatitis management. With the advent of direct-acting antivirals (DAAs), the treatment landscape has evolved, but peginterferon alfa-2a remains relevant due to its established efficacy, especially in specific patient populations and geographic regions. This report delves into recent clinical trial updates, analyzes market dynamics, and projects future trends for peginterferon alfa-2a.

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Clinical Trials Update

Recent Developments in Clinical Research

While the global shift toward interferon-free regimens has diminished the prominence of peginterferon alfa-2a, ongoing clinical trials continue to refine its therapeutic profile and explore new indications:

• Efficacy in Combination Therapies: Several Phase II and III trials investigate peginterferon alfa-2a combined with novel antivirals or immune modulators for resistant HCV genotypes. For example, recent studies focus on its use alongside effective DAAs in genotype 3 patients with prior treatment failure, assessing sustained virologic response (SVR) rates. Results show moderate efficacy, with SVR rates around 60-70%, indicating potential niche applications.

• Therapeutic Use in Non-HCV Viral Diseases: Clinicians are exploring peginterferon alfa-2a for conditions such as hepatitis B, certain hematologic malignancies, and emerging viral outbreaks. A recent phase II trial in hepatitis B patients demonstrated modest viral suppression, but no significant breakthroughs have been reported recently.

• Adverse Effect Management: New studies focus on mitigating interferon-associated adverse events through supportive strategies and dose optimization, aiming to expand tolerability in vulnerable populations like the elderly or those with comorbidities.

Regulatory and Market Withdrawals

Notably, regulatory agencies in Europe and North America have largely ceased approving new indications for peginterferon alfa-2a, reflecting its declining role. However, ongoing post-marketing surveillance continues to monitor long-term safety profiles.

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Market Analysis

Current Market Landscape

The global peginterferon alfa-2a market has experienced a profound contraction over the last decade. The advent of DAAs such as sofosbuvir, ledipasvir, and velpatasvir revolutionized HCV treatment, offering cure rates exceeding 95% with shorter, oral regimens and minimal side effects.

• Market Size and Decline: Estimated at over USD 1 billion in 2015, the market contracted by approximately 40% by 2022. The decline is driven mainly by shrinking patient populations suitable for interferon-based therapy and increasing preference for interferon-free protocols.

• Manufacturers and Supply Chain: Major pharmaceutical companies like Merck (markets under the brand name PegIntron) and Roche (Pegasys) dominate manufacturing. Patent expirations and generic entry have reduced prices, but demand remains limited primarily for specialty indications and regions with constrained healthcare resources.

• Geographic Variations: Peginterferon alfa-2a maintains niche importance in low-income countries where cost constraints preclude DAAs. Additionally, in populations where DAAs are contraindicated or ineffective, peginterferon alfa-2a retains therapeutic relevance.

Competitive Positioning

Compared to newer therapies, peginterferon alfa-2a faces stiff competition due to:

• Efficacy and Tolerability: DAAs demonstrate superior efficacy and tolerability profiles.
• Treatment Duration: Interferon-based regimens are longer and associated with significant side effects.
• Cost Dynamics: While cheaper in generic markets, overall treatment costs for interferon-based regimens remain higher when considering management of adverse events.

Regulatory and Policy Influences

Health authorities are increasingly discouraging interferon-based therapies in favor of oral DAAs, impacting future demand. Nevertheless, stockpiles and existing prescriptions sustain a minimal residual market.

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Market Projection

Forecast Assumptions

• Short-term (1-3 years): Continued decline in developed markets, with negligible growth due to minimal new approvals and existing stock utilization.
• Medium-term (3-5 years): Potential stabilization in low-resource regions; incremental use in niche indications such as certain hematologic disorders or drug-resistant HCV cases.
• Long-term (over 5 years): Expect significant market contraction, approaching exclusivity to legacy supply and select specialty indications.

Market Forecast

The global peginterferon alfa-2a market is projected to decline at a compound annual growth rate (CAGR) of approximately -10% to -15% over the next five years, driven by low growth or stable demand solely in underserved markets and research contexts.

• Emerging Markets: Growth in countries with limited access to newer therapies could sustain modest demand.
• Research and Development: Investigational uses in immune modulation or emerging viral infections may generate niche opportunities, but such prospects remain uncertain.

Financial Outlook

By 2028, market revenue could drop below USD 300 million, with some estimates indicating continued phase-out as alternative treatments dominate.

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Key Takeaways

• Declining Relevance: Peginterferon alfa-2a’s role diminishes globally, replaced predominantly by oral regimens with better safety and efficacy profiles.
• Niche Opportunities: Its sustained use persists mainly in low-income regions, specific resistant virus cases, and certain off-label indications.
• Clinical Innovation: Current trials focus on mitigating side effects and exploring new uses, but no groundbreaking breakthroughs are imminent.
• Market Trends: The overall market trajectory points toward decline, with limited prospects for growth outside specialty sectors.
• Strategic Focus: Companies should prioritize transition strategies, including repurposing or gradual phase-out, aligning with evolving standards of care.

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Frequently Asked Questions

1. Will peginterferon alfa-2a be phased out completely?
While its global market presence diminishes, peginterferon alfa-2a will remain in use in certain low-resource regions and specific clinical scenarios until fully replaced by more effective oral therapies.

2. Are there any ongoing clinical trials exploring new uses for peginterferon alfa-2a?
Yes, research continues into its application in certain hematological conditions, some viral infections, and immune modulation, but these are limited in number and scope.

3. How has the advent of direct-acting antivirals impacted peginterferon alfa-2a sales?
DAAs have largely displaced peginterferon alfa-2a in HCV treatment due to superior cure rates, shorter duration, and fewer side effects, leading to a significant market decline for the latter.

4. What are the main challenges facing manufacturers of peginterferon alfa-2a?
Key challenges include declining demand, competition from generics, regulatory hurdles in phasing out old formulations, and repositioning strategies in diminishing markets.

5. Is there potential for peginterferon alfa-2a in emerging infectious diseases?
While some early exploratory studies suggest possible immune-modulatory roles, its primary use remains limited, and no current evidence indicates a substantial future role in emerging infections.

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References

1. World Health Organization (WHO). Hepatitis C Fact Sheet. 2022.
2. U.S. Food and Drug Administration (FDA). Approval history of peginterferon alfa-2a (Pegasys). 2021.
3. GlobalData Healthcare. Hepatitis C treatment market analysis, 2022.
4. ClinicalTrials.gov. Ongoing studies involving peginterferon alfa-2a. Accessed 2023.
5. IQVIA. Pharmaceutical market trends, 2022.

(Note: All data are based on publicly available sources as of early 2023 and may fluctuate with new developments.)