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
NCT00000811 ↗	A Study to Compare Different Drugs Used to Prevent Serious Bacterial Infections in HIV-Positive Children	Completed	Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)	Phase 2	1969-12-31	This study compares 2 different treatments administered to try to prevent serious bacterial infections (such as pneumonia) in HIV-positive children. A combination of drugs (azithromycin plus atovaquone) will be compared to sulfamethoxazole-trimethoprim (SMX/TMP) alone. This study also evaluates the long-term safety and tolerance of these different drugs. SMX/TMP is a commonly prescribed drug for the prevention of bacterial infections. However, the combination of azithromycin and atovaquone may be safer and more effective than SMX/TMP. This study compares the 2 treatments.

Clinical Trial Conditions for ATOVAQUONE

Condition Name

Condition Name for ATOVAQUONE
Intervention	Trials
Malaria	12
HIV Infections	11
Pneumonia, Pneumocystis Carinii	8
Pneumocystis Jirovecii Infection	2

Condition MeSH

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

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
Georgia	7
California	7
North Carolina	7
New York	7

Clinical Trial Progress for ATOVAQUONE

Clinical Trial Phase

Clinical Trial Phase for ATOVAQUONE
Clinical Trial Phase	Trials
PHASE4	1
PHASE2	1
PHASE1	2

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	73
Industry	20
NIH	9

ATOVAQUONE: Clinical Trials Update, Market Analysis, and Projection

Last updated: April 28, 2026

What clinical-stage activity exists for atovaquone?

Atovaquone (originally developed as an antiparasitic) is in late-stage use across established indications and is not showing broad, sponsor-driven, late-stage global expansion into new, high-profile indications in recent public trial registries. Publicly visible clinical-trial “signal” in the last several years tends to concentrate in:

• Drug use and regimen optimization (dose, duration, formulation switches)
• Comparative effectiveness in real-world cohorts
• Combination studies tied to parasitic and infectious disease care pathways

Trial landscape (high-level):

• Active/registered interventional studies: Limited and usually small-to-midsize.
• Geography: Concentrated in countries with high endemic burden and active infectious disease research networks.
• Design pattern: Randomized comparisons or open-label regimen studies when new combinations are tested.

Public registry sources used for this update: ClinicalTrials.gov and the EU Clinical Trials Register. (No additional sources are required to support the registries-based activity picture in this write-up.)
Source: ClinicalTrials.gov [1]; EU Clinical Trials Register [2]

Which indications drive current atovaquone demand?

Commercially, atovaquone demand is anchored by established clinical use, with market activity tied to:

• Malaria prevention and treatment regimens (notably combination therapy with proguanil in “atovaquone/proguanil” products, depending on market labeling)
• Toxoplasmosis treatment and prophylaxis, particularly in immunocompromised patients where standard of care pathways include atovaquone-based options
• Pneumocystis pneumonia (PCP) prophylaxis and treatment pathways in selected settings
• Adjunctive infectious disease use in geographic and guideline-dependent patterns

Implication for R&D and forecasting: atovaquone faces a “mature pipeline” reality. Commercial growth depends more on guideline adherence, local procurement cycles, and competitor dynamics in each care setting than on new late-stage, novel MOA adoption. That shifts near-term value capture toward supply and access execution rather than breakthrough clinical differentiation.

Registry and regulatory status underpinning the above care-pathway anchoring is consistent with longstanding label utilization patterns (registries do not replace labeling, but they corroborate that ongoing studies are not dominated by a single new blockbuster indication).
Sources: ClinicalTrials.gov [1]; EU Clinical Trials Register [2]

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What is the current market structure for atovaquone?

Atovaquone is sold primarily through:

• Fixed-dose combination products where atovaquone partners with proguanil for malaria chemoprophylaxis and treatment regimens (market dynamics then track malaria seasonality and travel/expedition segments)
• Single-ingredient atovaquone products and generic versions depending on geography, tender cycles, and national formulary decisions

Market segmentation that matters for projections:

1. Institutional procurement (hospital and immunocompromised patient prophylaxis programs)
2. Travel medicine and malaria prophylaxis (seasonality and traveler volume)
3. Endemic-region procurement (public health program tendering)

Pricing and competition:

• Atovaquone faces competition from newer antiprotozoals in certain malaria contexts and from alternative prophylaxis regimens in immunocompromised care.
• Where atovaquone-based regimens remain standard or guideline-endorsed, procurement tends to be price- and availability-driven.
• Generics compress margins and make share gains harder without tender wins or supply advantages.

Why this matters for forecasting: in a generic and guideline-mediated market, volume is more durable than price. Revenue projection therefore tracks (a) treated patient numbers, (b) prophylaxis eligibility and persistence, and (c) tender capture.

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What assumptions drive a 3- to 5-year revenue projection for atovaquone?

This projection framework uses the most defensible levers for a mature antiparasitic with ongoing but limited late-stage novelty:

Demand levers

• Malaria chemoprophylaxis/treatment regimen uptake
  • Travel-related prophylaxis volume and guideline adherence in non-endemic markets
  • Programmatic treatment and prophylaxis in endemic regions
• HIV and immunocompromised prophylaxis
  • PCP prophylaxis eligibility, regimen switching, and persistent adherence patterns
• Guideline durability
  • Atovaquone’s positioning in care pathways tends to remain stable when resistance and safety profiles support continued use

Supply and pricing levers

• Generic penetration (volume lift offset by price erosion)
• Tender frequency and substitution (switching costs low, affecting pricing power)
• Manufacturing continuity (drug availability constraints can spike revenues temporarily in fragmented tender markets)

Clinical development levers

• Limited late-stage indication expansion
  • With few new late-stage outcomes dominating registries, the base case assumes growth comes from care-pathway persistence, not label expansion.

Sources for the “limited late-stage new indication” profile come from the trial activity footprint visible in public registries.
Sources: ClinicalTrials.gov [1]; EU Clinical Trials Register [2]

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What does the projection say for market direction?

Base case (directional)

• Revenue growth is modest and largely volume-led rather than price-led.
• Share is stable in established guideline settings; price compression persists where generics and tender competition dominate.
• Upside exists where supply constraints or guideline-driven preference favors atovaquone-based regimens in immunocompromised or malaria-related care.

Risk case (downside)

• Guideline substitution: alternative regimens reduce atovaquone-based prophylaxis uptake.
• Further price erosion: intensified generic tender competition in key geographies compresses margins.
• Supply normalization after temporary disruptions: short-term spikes fade.

These directional conclusions align with the clinical trial signal pattern: ongoing clinical activity exists but does not show a dominant, late-stage, label-expanding program profile in major registries.
Sources: ClinicalTrials.gov [1]; EU Clinical Trials Register [2]

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How should R&D and investment decisions be framed for atovaquone?

For decision-makers, the actionable takeaway is that atovaquone behaves like a mature, regimen-driven platform rather than a blockbuster growth engine.

R&D strategy that fits the market reality

• Prioritize formulation and access work (bioavailability, stability, manufacturability, and cost-of-goods) rather than betting on new indications that would require large late-stage investment.
• Target combination regimen optimization where existing use patterns leave room for incremental improvements in adherence or patient throughput.

Investment strategy

• In mature markets, value concentrates in:
  • Procurement participation and tender competitiveness
  • Manufacturing scale and continuity
  • Portfolio breadth across endemic and immunocompromised care procurement cycles

Clinical registry activity supports that the near-term horizon is not dominated by major late-stage novelty, which pushes value toward execution.
Sources: ClinicalTrials.gov [1]; EU Clinical Trials Register [2]

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Key Takeaways

• Atovaquone’s clinical-trial footprint in major registries shows ongoing but limited late-stage indication-expansion activity, consistent with a mature drug profile.
• Market demand concentrates in malaria regimen use and immunocompromised prophylaxis/treatment pathways where guideline durability supports baseline volume.
• Forecasts should assume modest growth, driven mainly by treated/prophylaxis volume and procurement cycles, with ongoing price pressure from generics and tender competition.
• The most investable upside in the 3- to 5-year horizon comes from execution in supply and tender wins, not from breakthrough clinical differentiation.
  Sources: ClinicalTrials.gov [1]; EU Clinical Trials Register [2]

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FAQs

1) Is atovaquone currently being tested for new major indications in late-stage trials?

Public registry activity does not show a dominant, late-stage, label-expanding indication program for atovaquone; trial activity is more consistent with optimization and regimen-focused studies. [1,2]

2) What drives atovaquone demand most: treatment or prophylaxis?

Demand is primarily prophylaxis- and regimen-driven in immunocompromised care, with malaria use also shaping volume through seasonality and travel or endemic procurement cycles. [1,2]

3) Does the generic market make atovaquone a low-growth opportunity?

It makes price growth harder, but it can preserve or lift volume through tender participation. Revenue growth tends to be modest and execution-heavy. [1,2]

4) What is the main clinical-risk to the market forecast?

Guideline substitution away from atovaquone-based prophylaxis or regimens, plus competitive shifts toward alternative molecules in malaria and PCP care pathways. [1,2]

5) Where is near-term upside most likely to come from?

From procurement execution and supply continuity that protect or expand share in guideline-led settings, plus incremental regimen/formulation improvements that improve access and uptake. [1,2]

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References

[1] ClinicalTrials.gov. “Search results for atovaquone.” U.S. National Library of Medicine. https://clinicaltrials.gov/
[2] European Union Clinical Trials Register. “Search results for atovaquone.” European Medicines Agency. https://www.clinicaltrialsregister.eu/