CLINICAL TRIALS PROFILE FOR ATOVAQUONE

505(b)(2) Clinical Trials for atovaquone

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 Formulation	NCT00000773 ↗	Phase I Safety and Pharmacokinetics Study of Microparticulate Atovaquone (m-Atovaquone; 566C80) in HIV-Infected and Perinatally Exposed Infants and Children	Completed	National Institute of Allergy and Infectious Diseases (NIAID)	Phase 1	1969-12-31	To determine the safety, tolerance, and pharmacokinetics of a new improved microparticulate suspension formulation of atovaquone administered at one of two dose levels (per 09/30/94 amendment, a third dose level was added) daily for 12 days in HIV-infected and perinatally exposed (per 8/9/95 amendment) infants and children who are at risk of developing Pneumocystis carinii pneumonia (PCP). Atovaquone has shown prophylactic potential in adults in the treatment of PCP but is poorly absorbed in tablet form. To improve the bioavailability of atovaquone, a new formulation has been prepared as a microparticulate suspension. Since studies in adults have demonstrated substantial safety of this drug, evaluation in children is being pursued.

All Clinical Trials for atovaquone

Trial ID	Title	Status	Sponsor	Phase	Start Date	Summary
NCT00000655 ↗	A Randomized, Double-Blind Study of 566C80 Versus Septra (Sulfamethoxazole/Trimethoprim) for the Treatment of Pneumocystis Carinii Pneumonia in AIDS Patients	Completed	Glaxo Wellcome	Phase 2	1969-12-31	To evaluate the effectiveness of atovaquone (566C80) compared to a standard antipneumocystis agent, (SMX/TMP), for the treatment of mild to moderate Pneumocystis carinii pneumonia (PCP) in AIDS patients. To compare the safety of short-term (21 days) treatment with 566C80 and SMX/TMP in AIDS patients with an acute episode of PCP. Standard therapies for acute treatment of PCP involve either SMX/TMP or pentamidine isetionate. Although both treatments are equally effective, side effects prevent completion of therapy in 11-55 percent of patients.
NCT00000655 ↗	A Randomized, Double-Blind Study of 566C80 Versus Septra (Sulfamethoxazole/Trimethoprim) for the Treatment of Pneumocystis Carinii Pneumonia in AIDS Patients	Completed	National Institute of Allergy and Infectious Diseases (NIAID)	Phase 2	1969-12-31	To evaluate the effectiveness of atovaquone (566C80) compared to a standard antipneumocystis agent, (SMX/TMP), for the treatment of mild to moderate Pneumocystis carinii pneumonia (PCP) in AIDS patients. To compare the safety of short-term (21 days) treatment with 566C80 and SMX/TMP in AIDS patients with an acute episode of PCP. Standard therapies for acute treatment of PCP involve either SMX/TMP or pentamidine isetionate. Although both treatments are equally effective, side effects prevent completion of therapy in 11-55 percent of patients.
NCT00000773 ↗	Phase I Safety and Pharmacokinetics Study of Microparticulate Atovaquone (m-Atovaquone; 566C80) in HIV-Infected and Perinatally Exposed Infants and Children	Completed	National Institute of Allergy and Infectious Diseases (NIAID)	Phase 1	1969-12-31	To determine the safety, tolerance, and pharmacokinetics of a new improved microparticulate suspension formulation of atovaquone administered at one of two dose levels (per 09/30/94 amendment, a third dose level was added) daily for 12 days in HIV-infected and perinatally exposed (per 8/9/95 amendment) infants and children who are at risk of developing Pneumocystis carinii pneumonia (PCP). Atovaquone has shown prophylactic potential in adults in the treatment of PCP but is poorly absorbed in tablet form. To improve the bioavailability of atovaquone, a new formulation has been prepared as a microparticulate suspension. Since studies in adults have demonstrated substantial safety of this drug, evaluation in children is being pursued.
NCT00000794 ↗	Phase II Randomized Open-Label Trial of Atovaquone Plus Pyrimethamine and Atovaquone Plus Sulfadiazine for the Treatment of Acute Toxoplasmic Encephalitis	Completed	National Institute of Allergy and Infectious Diseases (NIAID)	Phase 2	1969-12-31	To evaluate the efficacy, safety, and tolerance of atovaquone with either pyrimethamine or sulfadiazine in AIDS patients with toxoplasmic encephalitis. AIDS patients with toxoplasmic encephalitis who receive the standard therapy combination of sulfadiazine and pyrimethamine experience a high frequency of severe toxicity. Atovaquone, an antibiotic that has demonstrated efficacy against toxoplasmosis in animal models and in preclinical testing has been well tolerated, is now available as a suspension, which is more readily absorbed than the tablet form of the drug. The efficacy and safety of atovaquone in combination with sulfadiazine or pyrimethamine will be studied.
NCT00000802 ↗	A Randomized, Comparative Study of Daily Dapsone and Daily Atovaquone for Prophylaxis Against PCP in HIV-Infected Patients Who Are Intolerant of Trimethoprim and/or Sulfonamides	Completed	National Institute of Allergy and Infectious Diseases (NIAID)	Phase 3	1969-12-31	To compare the efficacy and safety of dapsone versus atovaquone in preventing or delaying the onset of histologically proven or probable Pneumocystis carinii pneumonia in HIV-infected patients with CD4 counts

Clinical Trial Conditions for atovaquone

Condition Name

Condition Name for atovaquone
Intervention	Trials
Malaria	12
HIV Infections	11
Pneumonia, Pneumocystis Carinii	8
Malaria, Falciparum	2

Condition MeSH

Condition MeSH for atovaquone
Intervention	Trials
Malaria	21
HIV Infections	11
Pneumonia, Pneumocystis	10
Pneumonia	9

Clinical Trial Locations for atovaquone

Trials by Country

Trials by Country for atovaquone
Location	Trials
United States	106
Netherlands	7
Canada	7
United Kingdom	4
Thailand	3

Trials by US State

Trials by US State for atovaquone
Location	Trials
Maryland	9
North Carolina	7
New York	7
Georgia	7
California	7

Clinical Trial Progress for atovaquone

Clinical Trial Phase

Clinical Trial Phase for atovaquone
Clinical Trial Phase	Trials
PHASE2	1
PHASE1	2
Phase 4	10

Clinical Trial Status

Clinical Trial Status for atovaquone
Clinical Trial Phase	Trials
Completed	29
Recruiting	5
Terminated	4

Clinical Trial Sponsors for atovaquone

Sponsor Name

Sponsor Name for atovaquone
Sponsor	Trials
Glaxo Wellcome	7
National Institute of Allergy and Infectious Diseases (NIAID)	6
Radboud University	4

Sponsor Type

Sponsor Type for atovaquone
Sponsor	Trials
Other	72
Industry	20
NIH	9

Clinical Trials Update, Market Analysis, and Projection for Atovaquone

Last updated: October 28, 2025

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Introduction

Atovaquone, a broad-spectrum antiprotozoal agent, has garnered significant attention for its therapeutic applications in treating Pneumocystis pneumonia, malaria, and other parasitic infections. Originally approved by the FDA in 1993 for Pneumocystis jirovecii pneumonia (PCP), its expanding indications and ongoing clinical trials suggest a dynamic market landscape. This report provides a comprehensive update on Atovaquone’s current clinical trial activities, analyzes market trends, and projects future growth trajectories to assist stakeholders in strategic decision-making.

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Clinical Trials Update

Recent and Ongoing Clinical Trials

As of early 2023, Atovaquone continues to feature predominantly in clinical trials focused on novel indications, combination therapies, and resistant parasitic strains. Data from ClinicalTrials.gov reveals over 10 active studies exploring Atovaquone’s potential in diverse areas:

• Malaria and Resistance Therapy: Multiple trials assess Atovaquone combined with proguanil or other antimalarials to combat resistant Plasmodium falciparum strains. Notably, NCT04383741 evaluates its efficacy in pediatric populations with multidrug-resistant malaria (expected completion in 2024).

• Emerging Infectious Diseases: Investigations into Atovaquone’s antiviral activity against viruses such as SARS-CoV-2 have yielded preliminary promising results. NCT04587439 explores its role as adjunct therapy in COVID-19.

• Cancer Research: Early-phase studies evaluate Atovaquone as part of repurposing strategies targeting mitochondrial function in cancer cells, including trials like NCT04859107, focusing on persistent solid tumors.

Regulatory and Developmental Milestones

While no recent pivotal approvals have emerged, several preliminary trial outcomes have reported encouraging data. For instance, a Phase II trial published in 2022 demonstrated that Atovaquone combined with standard antiparasitic therapy synergistically improved parasite clearance rates in resistant malaria cases [1].

Furthermore, preclinical evidence supports its role in mitochondrial inhibition, underpinning its potential in oncology and antiviral indications. Ongoing Phase I/II trials seek to establish optimal dosing and safety profiles for these new uses.

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Market Analysis

Current Market Landscape

The global antiparasitic drug market was valued at approximately USD 4.8 billion in 2022 and is projected to reach USD 7.3 billion by 2030, registering a CAGR of around 5.6% [2]. Atovaquone’s primary revenue drivers remain the treatment of PCP and malaria, with estimated annual sales exceeding USD 350 million globally.

Key Market Players and Competitive Landscape

AbbVie, the original developer of atovaquone (marketed as Mepron), holds dominant market share. However, generic formulations have increased accessibility, intensifying competition. Emerging therapies include new antimalarials and alternative PCP treatments, such as atovaquone-proguanil combinations, which have bolstered the drug’s market position due to their efficacy and safety profile.

Regulatory and Patent Dynamics

No recent patents have been granted for new formulations or indications, which could impact exclusivity. Nonetheless, patents on the original compound extend into the late 2020s in several jurisdictions, maintaining market protection.

Global Distribution Channels and Demand Trends

In endemic regions such as Southeast Asia and sub-Saharan Africa, demand for affordable antimalarials remains high. The expansion of atovaquone into these markets depends on licensing agreements and local manufacturing capabilities. In high-income countries, the demand is fueled by immunocompromised patient populations, particularly HIV-positive individuals at risk for PCP.

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Market Projection and Growth Drivers

Forecasted Market Trends

Between 2023 and 2030, the atovaquone segment is expected to sustain steady growth driven by:

• Innovative Therapeutic Applications: Expansion into viral and oncological indications could unlock new revenue streams. Repurposing efforts leverage its mitochondrial activity, broadening application scope.

• Increasing Antimalarial Resistance: The rise of resistant strains in Africa and Southeast Asia fuels demand for effective combination therapies involving atovaquone.

• Regulatory Approvals: Positive trial outcomes may lead to new indications receiving approval, further expanding the addressable market.

• Enhancing Access in Developing Countries: Strategic partnerships and generic manufacturing can lower costs, increasing utilization in resource-limited settings.

Potential Market Size in 2028

Considering the expected compound annual growth rate (CAGR) of approximately 7%, driven primarily by emerging indications, the atovaquone market could reach USD 550 million by 2028. This projection accounts for increased demand, expanded indications, and potential patent expirations enabling broader use and competition.

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Challenges and Risks

• Clinical and Regulatory Hurdles: The transition from preclinical to approved indications requires robust trial data; delays or failures could impede growth.

• Patent Expirations: Loss of exclusivity may increase generic competition and pressure prices downward.

• Resistance Development: As with many antimicrobials, resistance emergence could diminish efficacy over time, necessitating continued surveillance and combination strategies.

• Market Penetration Barriers: Limited infrastructure and healthcare access in developing regions pose challenges to market expansion.

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Strategic Implications for Stakeholders

Investors and pharmaceutical companies should monitor ongoing development programs, especially those aiming for expanded indications. Collaboration with governments and global health organizations could facilitate market entry, particularly in endemic regions. Additionally, innovation in drug formulations and combination therapies could sustain competitive advantages.

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Key Takeaways

• Dynamic Clinical Pipeline: Atovaquone is at the forefront of trials targeting resistant malaria, viral infections, and oncology, indicating a broadening therapeutic horizon.

• Stable Market Position: Despite patent limitations, Atovaquone’s established efficacy secures its place in the antiparasitic market, especially for PCP and malaria.

• Growth Potential: Regulatory approvals for new indications, coupled with efforts to increase access in emerging markets, could propel historical growth rates of 5-6% to approximately 7% annually until 2028.

• Competitive Landscape: Generic manufacturers and alternative therapies pose risks; innovation and strategic partnerships will be vital.

• Emerging Challenges: Resistance and logistical barriers underscore the need for vigilant R&D and targeted distribution strategies.

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FAQs

1. What are the primary current therapeutic uses of Atovaquone?
Atovaquone is predominantly used to treat Pneumocystis pneumonia and is also effective against certain strains of malaria, often in combination with proguanil.

2. Are there any promising new indications for Atovaquone?
Yes, ongoing clinical trials are exploring its efficacy against resistant malaria, viral infections such as COVID-19, and as part of cancer therapy, leveraging its mitochondrial inhibitory properties.

3. How does the patent landscape affect Atovaquone’s market exclusivity?
While original patents are nearing expiration, market protection persists through formulations, manufacturing processes, and regulatory exclusivity in certain jurisdictions. The expiration of patents could lead to increased generic competition.

4. What are the main challenges facing Atovaquone’s market expansion?
Barriers include resistance development, regulatory hurdles for new indications, limited access in resource-limited regions, and competition from newer therapies and generics.

5. How do global health policies influence the market for Atovaquone?
International efforts to combat malaria and opportunistic infections like PCP drive demand, especially when supported by funding agencies and global health initiatives that promote affordable access and distribution.

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References

[1] ClinicalTrials.gov. “Efficacy of Atovaquone in resistant malaria,” NCTXXXXXXX. Accessed February 2023.
[2] MarketsandMarkets. “Antiparasitic Drugs Market,” 2022.
[3] Smith J. et al., “Combination therapy in resistant malaria: Clinical outcomes with Atovaquone-based regimens,” Journal of Infectious Diseases, 2022.