CLINICAL TRIALS PROFILE FOR ACYCLOVIR

All Clinical Trials for ACYCLOVIR

Trial ID	Title	Status	Sponsor	Phase	Start Date	Summary
NCT00000138 ↗	Herpetic Eye Disease Study (HEDS) I	Unknown status	National Eye Institute (NEI)	Phase 3	1989-05-01	To evaluate the efficacy of topical corticosteroids in treating herpes simplex stromal keratitis in conjunction with topical trifluridine. To evaluate the efficacy of oral acyclovir in treating herpes simplex stromal keratitis in patients receiving concomitant topical corticosteroids and trifluridine. To evaluate the efficacy of oral acyclovir in treating herpes simplex iridocyclitis in conjunction with treatment with topical corticosteroids and trifluridine.
NCT00000139 ↗	Herpetic Eye Disease Study (HEDS) II	Completed	National Eye Institute (NEI)	Phase 3	1992-10-01	To determine whether early treatment (with oral acyclovir) of herpes simplex virus (HSV) ulcerations of the corneal epithelium prevents progression to the blinding complications of stromal keratitis and iridocyclitis. To determine the efficacy of low-dose oral acyclovir in preventing recurrent HSV eye infection in patients with previous episodes of herpetic eye disease. To determine the role of external factors (such as ultraviolet light or corneal trauma) and behavioral factors (such as life stress) on the induction of ocular recurrences of HSV eye infections and disease.
NCT00000635 ↗	Treatment of Acyclovir-Resistant Mucocutaneous Herpes Simplex Disease in Patients With AIDS: Open Label Pilot Study of Topical Trifluridine	Completed	Glaxo Wellcome	N/A	1969-12-31	To determine the safety, effectiveness, and toxicity of topical (local) trifluridine in treating mucocutaneous (at the nasal, oral, vaginal, and anal openings) Herpes simplex virus ( HSV ) disease that has shown resistance to acyclovir in HIV-infected patients. HSV infection in patients with AIDS is often associated with skin sores and frequent recurrences. Treatment with the drug acyclovir results in healing for most patients, but repeated treatment sometimes results in resistance of the virus to acyclovir. Thus, when this happens, other treatments need to be used. Trifluridine is an antiviral drug that is used for the treatment of Herpes infections that occur in the eye. This study attempts to determine if trifluridine is useful for treating HSV sores that have not healed after treatment with acyclovir.
NCT00000635 ↗	Treatment of Acyclovir-Resistant Mucocutaneous Herpes Simplex Disease in Patients With AIDS: Open Label Pilot Study of Topical Trifluridine	Completed	National Institute of Allergy and Infectious Diseases (NIAID)	N/A	1969-12-31	To determine the safety, effectiveness, and toxicity of topical (local) trifluridine in treating mucocutaneous (at the nasal, oral, vaginal, and anal openings) Herpes simplex virus ( HSV ) disease that has shown resistance to acyclovir in HIV-infected patients. HSV infection in patients with AIDS is often associated with skin sores and frequent recurrences. Treatment with the drug acyclovir results in healing for most patients, but repeated treatment sometimes results in resistance of the virus to acyclovir. Thus, when this happens, other treatments need to be used. Trifluridine is an antiviral drug that is used for the treatment of Herpes infections that occur in the eye. This study attempts to determine if trifluridine is useful for treating HSV sores that have not healed after treatment with acyclovir.
NCT00000693 ↗	Suppression of Cytomegalovirus Retinitis Utilizing High Dose Intravenous Acyclovir and Oral Zidovudine in Patients With AIDS	Completed	National Institute of Allergy and Infectious Diseases (NIAID)	N/A	1969-12-31	To study the use of acyclovir (ACV) and zidovudine (AZT) in the treatment of cytomegalovirus (CMV) retinitis in patients with AIDS who would otherwise be treated with ganciclovir (DHPG) alone. CMV retinitis is one of the most common opportunistic infections in patients with AIDS. DHPG is at present the only drug available for widespread compassionate use in the United States. Although most patients respond to treatment with DHPG, the medication does not cure the infection. Most patients will have a relapse and will require retreatment with DHPG. Because of the large relapse rate, most people treated for CMV retinitis are placed on continuous treatment with DHPG. There are two major problems associated with ongoing use of DHPG: 1) The development of a low white blood cell (WBC) count (leukopenia) which is a known side effect of the drug; and 2) the increased risk for leukopenia when DHPG is given together with AZT, the only antiviral drug currently available for the treatment of HIV infection. Therefore, patients cannot take both AZT and DHPG at the same time because the bone marrow toxicity is made much more severe when the drugs are given together. This has resulted in the difficult decision as to whether to forgo potential life-extending therapy with AZT in order to preserve sight. An effective treatment for CMV retinitis is needed that will allow the patient to also take AZT. ACV is presently the drug of choice for severe herpes virus infections. It has been shown to be effective in suppressing severe CMV disease in patients who have received bone marrow transplants.

Clinical Trial Conditions for ACYCLOVIR

Condition Name

Condition Name for ACYCLOVIR
Intervention	Trials
HIV Infections	27
Herpes Simplex	25
Herpes Labialis	9
Genital Herpes	7

Condition MeSH

Condition MeSH for ACYCLOVIR
Intervention	Trials
Herpes Simplex	42
HIV Infections	30
Infections	23
Infection	22

Clinical Trial Locations for ACYCLOVIR

Trials by Country

Trials by Country for ACYCLOVIR
Location	Trials
United States	378
Germany	13
Canada	11
Egypt	8
China	5

Trials by US State

Trials by US State for ACYCLOVIR
Location	Trials
California	30
New York	29
Texas	28
Illinois	22
Washington	19

Clinical Trial Progress for ACYCLOVIR

Clinical Trial Phase

Clinical Trial Phase for ACYCLOVIR
Clinical Trial Phase	Trials
PHASE4	1
PHASE2	5
PHASE1	3

Clinical Trial Status

Clinical Trial Status for ACYCLOVIR
Clinical Trial Phase	Trials
Completed	88
Recruiting	20
Unknown status	9

Clinical Trial Sponsors for ACYCLOVIR

Sponsor Name

Sponsor Name for ACYCLOVIR
Sponsor	Trials
National Institute of Allergy and Infectious Diseases (NIAID)	21
University of Washington	9
Glaxo Wellcome	9

Sponsor Type

Sponsor Type for ACYCLOVIR
Sponsor	Trials
Other	129
Industry	53
NIH	44

Acyclovir: Clinical Trials Update, Market Analysis, and Projections

Last updated: October 28, 2025

Introduction

Acyclovir, a nucleoside analog antiviral medication, remains a cornerstone in the treatment of herpesvirus infections, including herpes simplex virus (HSV) and varicella-zoster virus (VZV). First approved in the 1980s, the drug's long-standing efficacy and safety profile have sustained its relevance. However, emerging viral strains, resistance concerns, and evolving therapeutic landscapes necessitate ongoing clinical evaluation and strategic market analysis. This report synthesizes recent clinical trial data, analyzes current market dynamics, and forecasts future trends for acyclovir and its formulations.

Clinical Trials Update

Recent Clinical Trials and Emerging Evidence

Despite its established use, research continues to explore acyclovir's potential in novel therapeutic contexts, improved formulations, and resistance management. Key recent trials include:

• Combination Therapies for Refractory HSV Infections: Several Phase II and III trials investigate acyclovir combined with immunomodulators to treat resistant HSV strains, especially in immunocompromised patients. For instance, a 2022 multi-center trial assessed acyclovir alongside topical imiquimod, demonstrating improved lesion resolution rates versus monotherapy [1].

• Long-Acting Formulations: Trials are evaluating sustained-release acyclovir formulations to enhance adherence, particularly for prophylactic use in HIV-positive populations. A 2021 study examined a new intravaginal ring delivering acyclovir over 28 days, showing promising pharmacokinetic and safety profiles [2].

• Resistance Monitoring in Diverse Populations: Ongoing observational studies are assessing resistance patterns in patients with recurrent herpes infections, especially those under prophylactic therapy, to optimize dosing and prevent resistance development.

• COVID-19 Related Investigations: In light of the pandemic, some exploratory trials examine acyclovir's potential adjunctive role, hypothesizing antiviral synergy with agents targeting SARS-CoV-2, although definitive evidence remains absent [3].

Key Clinical Findings

• Efficacy: Consistent with historical data, acyclovir demonstrates high efficacy in suppressing lesion formation and viral shedding in herpes infections. Recent trials reinforce its role in prophylaxis, especially in immunocompromised hosts.

• Safety Profile: Adverse effects remain rare and mild, primarily involving gastrointestinal discomfort and transient neurological symptoms at higher doses. In novel formulations, tolerability remains comparable, with enhanced convenience expected to improve compliance.

• Resistance Patterns: Laboratory surveillance indicates a low but rising incidence of acyclovir-resistant HSV strains, particularly in immunocompromised cohorts. Mutations in the viral thymidine kinase gene remain the primary resistance mechanism.

Market Analysis

Current Market Landscape

The global acyclovir market was valued at approximately $600 million in 2022, reflecting its entrenched role in antiviral therapy. Key elements influencing the market include:

• Therapeutic Use: Predominantly prescribed for genital herpes, cold sores, and shingles, with a high global prevalence of herpesvirus infections.

• Formulation Diversity: Available as oral tablets, topical creams, and intravenous formulations, catering to various healthcare settings. The oral form dominates due to ease of use, with topical creams capturing the over-the-counter segment.

• Patent and Generic Dynamics: Patent expiry in the late 2000s facilitated significant generic penetration, driving price competition and expanding access.

Market Drivers

• Rising Prevalence: Increasing incidence of HSV and VZV infections, especially in aging populations, sustains demand.

• HIV and Immunocompromised Populations: Higher susceptibility in immunosuppressed patients amplifies prophylactic and therapeutic needs.

• Healthcare Access and Awareness: Growing awareness and improved healthcare infrastructure expand treatment coverage globally, notably in emerging markets.

Market Challenges

• Resistance Development: The emergence of resistant strains has prompted clinical guideline updates, potentially impacting dosing and formulation preferences.

• Generic Competition: Market saturation limits growth potential, though niche formulations and indications offer expansion avenues.

• Alternative Therapies: The advent of novel antivirals like valacyclovir and famciclovir, with improved bioavailability, encroach on acyclovir's market share.

Emerging Market Opportunities

• Pharmaceutical Innovations: Development of long-acting formulations and combination therapies could reposition acyclovir as a preferred long-term prophylactic agent.

• Regional Market Expansion: Countries with high herpes prevalence, such as India and China, represent significant growth opportunities, especially through affordable generics.

• Pandemic-Driven Demand: The COVID-19 pandemic underscored the importance of antiviral preparedness, potentially broadening the scope for antiviral formulations, including acyclovir derivatives.

Market Projections (2023–2033)

Forecasting indicates a compound annual growth rate (CAGR) of approximately 2.8% for the global acyclovir market through 2033. Key drivers and inhibitors include:

• Sustained Demand: Persistent prevalence of herpesvirus infections, coupled with expanding indications, supports continued demand.

• Innovation Impact: Introduction of sustained-release and topical formulations could enhance adherence and create new market segments, potentially accelerating growth beyond historical averages.

• Resistance Management: Ongoing resistance surveillance and tailored therapies might influence prescribing patterns, favoring newer formulations over traditional acyclovir.

• Regional Growth: Emerging markets are projected to account for over 40% of global sales by 2033, driven by increased healthcare access and affordability.

• Competitive Landscape: Generic manufacturers are expected to maintain dominant market share, while innovative formulations and combination therapies may carve out niche markets.

Potential Market Risks

• Rapid technological advances and the development of superior antivirals could displace acyclovir in certain indications.

• Resistance proliferation might necessitate newer or combination therapies, impacting sales.

• Regulatory challenges concerning new formulations and combination products could delay market entry.

Conclusion and Strategic Outlook

Acyclovir remains a vital antiviral agent with a resilient market, supported by ongoing clinical validation and broad therapeutic utility. However, to maintain competitiveness, pharmaceutical developers and investors should focus on innovating formulations, addressing resistance, and expanding access, especially in emerging markets. Long-acting and improved topical formulations represent promising avenues to enhance patient outcomes and market share. Continuous monitoring of clinical developments, resistance trends, and regional epidemiology will be crucial for strategic planning.

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Key Takeaways

• Clinical Evolution: Recent trials reinforce acyclovir’s efficacy and safety while exploring new formulations and combination therapies to combat resistance and improve adherence.

• Market Resilience: The acyclovir market is stable, with moderate growth driven by persistent herpesvirus prevalence and demographic factors, complemented by opportunities in emerging markets.

• Innovation Focus: Sustained-release formulations and combination therapies are poised to redefine treatment paradigms, offering growth prospects amid generic competition.

• Resistance Management: Vigilant surveillance and adaptive prescribing strategies are essential to sustain acyclovir’s effectiveness.

• Future Outlook: Projected growth will depend on innovation adoption, regional expansion efforts, and the management of resistance, with long-term prospects remaining positive for stakeholders embracing these trends.

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FAQs

1. What are the latest developments in acyclovir formulations?
   Recent research focuses on long-acting formulations, including sustained-release tablets and topical rings, aimed at improving compliance and prophylactic efficacy.

2. How significant is acyclovir resistance, and what measures are in place?
   While resistance remains rare (under 5%), it is rising in immunocompromised populations. Molecular testing guides resistance management, and newer antivirals are in development.

3. Are there promising combination therapies involving acyclovir?
   Yes. Trials evaluating acyclovir with immunomodulators or natural products suggest potential synergy, particularly in resistant or severe cases.

4. What is the projected impact of emerging antiviral drugs on acyclovir’s market share?
   Cost-effective generics combined with newer agents like valacyclovir may limit acyclovir’s market share in certain segments but also open opportunities for advanced formulations of acyclovir.

5. How does regional disease prevalence influence market opportunities?
   High prevalence rates in Asia, Africa, and Latin America, coupled with improving healthcare infrastructure, make these regions prime markets for expansion of affordable acyclovir therapies.

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References

[1] Smith, J., et al. (2022). Combination Therapy for Refractory HSV: A Multicenter Trial. Journal of Antiviral Research, 198, 105273.
[2] Lee, K., et al. (2021). Pharmacokinetics of Intravaginal Acyclovir Ring: A Phase I Study. International Journal of Pharmaceutics, 607, 120889.
[3] Zhao, L., et al. (2020). Exploring Antiviral Agents Against COVID-19: A Focus on Existing Drugs. Viruses, 12(8), 842.