CLINICAL TRIALS PROFILE FOR SULFADIAZINE

All Clinical Trials for Sulfadiazine

Trial ID	Title	Status	Sponsor	Phase	Start Date	Summary
NCT00000666 ↗	A Randomized Prospective Study of Pyrimethamine Therapy for Prevention of Toxoplasmic Encephalitis in HIV-Infected Individuals With Serologic Evidence of Latent Toxoplasma Gondii Infection	Completed	National Institute of Allergy and Infectious Diseases (NIAID)	N/A	1969-12-31	To evaluate pyrimethamine as a prophylactic agent against toxoplasmic encephalitis in individuals who are coinfected with HIV and latent Toxoplasma gondii. Toxoplasmic encephalitis is a major cause of illness and death in AIDS patients. Standard treatment for toxoplasmic encephalitis is to combine pyrimethamine and sulfadiazine. Continuous treatment is necessary to prevent recurrence of the disease, but constant use of pyrimethamine/sulfadiazine is associated with toxicity. Clindamycin has been shown to be effective in treatment of toxoplasmic encephalitis in animal studies. This study evaluates pyrimethamine as a preventive treatment against toxoplasmic encephalitis (per 3/26/91 amendment, clindamycin arm was discontinued).
NCT00000674 ↗	A Pilot Study of Oral Clindamycin and Pyrimethamine for the Treatment of Toxoplasmic Encephalitis in Patients With AIDS	Completed	Glaxo Wellcome	N/A	1969-12-31	To collect information on the effectiveness and toxicity of clindamycin plus pyrimethamine and leucovorin calcium for the treatment of acute toxoplasmic encephalitis in adult patients with AIDS. Toxoplasmic encephalitis (encephalitis caused by Toxoplasma gondii) is the most frequent cause of focal central nervous system infection in patients with AIDS. If untreated, the encephalitis is fatal. At present, it is standard practice to give a combination of pyrimethamine and sulfadiazine to treat toxoplasmic encephalitis. The high frequency of sulfonamide-induced toxicity in AIDS patients often makes completion of a full course of therapy difficult. There is some information that high doses of parenteral (such as by injection) clindamycin used with pyrimethamine may be as effective as pyrimethamine plus sulfadiazine in the management of the acute phase of toxoplasmic encephalitis in patients with AIDS. Administration of parenteral clindamycin for prolonged periods of time, however, is costly, requires hospitalization, and is inconvenient for the patient. There is some indication that treatment of AIDS patients with acute toxoplasmic encephalitis with oral clindamycin may be effective. Leucovorin calcium is useful in preventing pyrimethamine-associated bone marrow toxicity.
NCT00000674 ↗	A Pilot Study of Oral Clindamycin and Pyrimethamine for the Treatment of Toxoplasmic Encephalitis in Patients With AIDS	Completed	Upjohn	N/A	1969-12-31	To collect information on the effectiveness and toxicity of clindamycin plus pyrimethamine and leucovorin calcium for the treatment of acute toxoplasmic encephalitis in adult patients with AIDS. Toxoplasmic encephalitis (encephalitis caused by Toxoplasma gondii) is the most frequent cause of focal central nervous system infection in patients with AIDS. If untreated, the encephalitis is fatal. At present, it is standard practice to give a combination of pyrimethamine and sulfadiazine to treat toxoplasmic encephalitis. The high frequency of sulfonamide-induced toxicity in AIDS patients often makes completion of a full course of therapy difficult. There is some information that high doses of parenteral (such as by injection) clindamycin used with pyrimethamine may be as effective as pyrimethamine plus sulfadiazine in the management of the acute phase of toxoplasmic encephalitis in patients with AIDS. Administration of parenteral clindamycin for prolonged periods of time, however, is costly, requires hospitalization, and is inconvenient for the patient. There is some indication that treatment of AIDS patients with acute toxoplasmic encephalitis with oral clindamycin may be effective. Leucovorin calcium is useful in preventing pyrimethamine-associated bone marrow toxicity.
NCT00000674 ↗	A Pilot Study of Oral Clindamycin and Pyrimethamine for the Treatment of Toxoplasmic Encephalitis in Patients With AIDS	Completed	National Institute of Allergy and Infectious Diseases (NIAID)	N/A	1969-12-31	To collect information on the effectiveness and toxicity of clindamycin plus pyrimethamine and leucovorin calcium for the treatment of acute toxoplasmic encephalitis in adult patients with AIDS. Toxoplasmic encephalitis (encephalitis caused by Toxoplasma gondii) is the most frequent cause of focal central nervous system infection in patients with AIDS. If untreated, the encephalitis is fatal. At present, it is standard practice to give a combination of pyrimethamine and sulfadiazine to treat toxoplasmic encephalitis. The high frequency of sulfonamide-induced toxicity in AIDS patients often makes completion of a full course of therapy difficult. There is some information that high doses of parenteral (such as by injection) clindamycin used with pyrimethamine may be as effective as pyrimethamine plus sulfadiazine in the management of the acute phase of toxoplasmic encephalitis in patients with AIDS. Administration of parenteral clindamycin for prolonged periods of time, however, is costly, requires hospitalization, and is inconvenient for the patient. There is some indication that treatment of AIDS patients with acute toxoplasmic encephalitis with oral clindamycin may be effective. Leucovorin calcium is useful in preventing pyrimethamine-associated bone marrow toxicity.
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.
NCT00000973 ↗	A Study of Pyrimethamine in the Treatment of Infection by a Certain Parasite in HIV-Positive Patients	Completed	Glaxo Wellcome	Phase 1	1969-12-31	To determine the manner in which pyrimethamine is metabolized and excreted in patients currently receiving zidovudine (AZT). An important goal of this measurement is to establish the optimal dose of pyrimethamine necessary to prevent the development of toxoplasmosis in AIDS patients or delay the subsequent return of toxoplasmic encephalitis. Encephalitis caused by Toxoplasma gondii has emerged as the most frequent cause of focal central nervous system infection in patients with AIDS. Untreated, the encephalitis is fatal. The best treatment for this disease has not been determined. Presently it is standard practice to administer a combination of pyrimethamine and sulfadiazine. Little is known about the pharmacokinetics of pyrimethamine in patients with AIDS receiving AZT. Furthermore, there are reports that patients already exposed to toxoplasmosis may not have uniform absorption of pyrimethamine.

Clinical Trial Conditions for Sulfadiazine

Condition Name

Condition Name for Sulfadiazine
Intervention	Trials
HIV Infections	6
Burns	5
Toxoplasmosis, Cerebral	5
Burn	3

Condition MeSH

Condition MeSH for Sulfadiazine
Intervention	Trials
Burns	12
Toxoplasmosis	8
HIV Infections	6
Encephalitis	5

Clinical Trial Locations for Sulfadiazine

Trials by Country

Trials by Country for Sulfadiazine
Location	Trials
United States	52
China	6
Canada	5
Brazil	3
Thailand	2

Trials by US State

Trials by US State for Sulfadiazine
Location	Trials
California	5
New York	5
Illinois	4
Maryland	4
Virginia	4

Clinical Trial Progress for Sulfadiazine

Clinical Trial Phase

Clinical Trial Phase for Sulfadiazine
Clinical Trial Phase	Trials
PHASE4	1
Phase 4	5
Phase 3	5

Clinical Trial Status

Clinical Trial Status for Sulfadiazine
Clinical Trial Phase	Trials
Completed	22
Unknown status	4
Terminated	1

Clinical Trial Sponsors for Sulfadiazine

Sponsor Name

Sponsor Name for Sulfadiazine
Sponsor	Trials
National Institute of Allergy and Infectious Diseases (NIAID)	5
Glaxo Wellcome	3
Nucleo De Pesquisa E Desenvolvimento De Medicamentos Da Universidade Federal Do Ceara	3

Sponsor Type

Sponsor Type for Sulfadiazine
Sponsor	Trials
Other	30
Industry	8
NIH	6

Sulfadiazine Market Analysis and Financial Projection

Last updated: April 25, 2026

Sulfadiazine: clinical-trial status, market footprint, and revenue outlook

What is sulfadiazine’s current clinical-trial and regulatory trajectory?

Sulfadiazine is an older sulfonamide antibacterial. Clinical-development activity for “sulfadiazine” as a standalone systemic drug is limited in the modern randomized-trial landscape because the product is established, off-patent in most jurisdictions, and typically positioned as a legacy generic rather than a proprietary development program.

ClinicalTrials.gov (trial volume and recency)

• No reliable, current, actionable “active development” signal can be produced from the publicly accessible trial record universe without risking inaccurate indexing by formulation, synonym coverage, and combination products (e.g., topical/salt forms, veterinary indications, or bundled anti-infective regimens).
• Because the same API name “sulfadiazine” appears across multiple contexts, any clean “clinical trials update” for the single molecule requires a verified indication-level and sponsor-level filter that is not available in the provided data.

Practical implication for R&D and investment

• Treat sulfadiazine as a market-access and supply-chain play more than a “pipeline upside” play, unless you have an indication-specific development program (not provided here).
• For commercialization, the dominant levers are generic pricing, regulatory approvals, distribution contracts, and pharmacovigilance cost, not trial execution.

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Where does sulfadiazine sit in the treatment landscape by use case?

Sulfadiazine’s historical role is tied to sulfonamide antibacterial activity and, in some settings, use in specific infections depending on local formularies and resistance patterns. Commercial positioning typically occurs through:

• Generic oral or injectable antibacterial products (where marketed).
• Formulation-specific offerings (including topical uses in certain regions and veterinary lines, depending on local approvals).
• Combination regimens where “sulfadiazine” is part of a multi-agent therapy (which changes both competitive set and market sizing).

Because the question targets “Sulfadiazine” without an indication, dosage form, geography, or route, market analysis must be anchored to generic antibacterial economics rather than to a single clinical niche.

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How big is the sulfadiazine market and how does the competitive set behave?

For legacy, off-patent antibacterials, the market is usually characterized by:

• Low unit economics and rapid price compression after generic entries.
• Limited differentiation beyond bioequivalence and manufacturing control.
• Tender-driven procurement in institutional settings.
• High sensitivity to antimicrobial stewardship policies that constrain older sulfonamides in some formularies.

Competitive set structure (typical for off-patent systemic antibacterials)

• Multiple generic manufacturers with overlapping product claims.
• Price-led competition where margin is driven by scale and procurement terms.
• Regulatory compliance costs (quality system, batch release, stability, pharmacovigilance) as a key barrier to late entrants rather than clinical trial cost.

What can be concluded from available evidence

• A precise global “market size” number cannot be stated without a defined product scope (strength, dosage form, indication) and without access to payor and procurement datasets.
• Any single “market share” claim would be structurally fragile because “sulfadiazine” revenues are typically reported under multiple therapeutic classification buckets by different data vendors.

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What revenue projections are realistic for sulfadiazine?

Without indication-level and territory-level scope, the only defensible projection framework for sulfadiazine is generic revenue mechanics:

Projection drivers

• Volume stability: driven by guideline/formulary presence and procurement continuity.
• Price compression: ongoing erosion after generic introductions.
• Supply continuity: disruptions can cause temporary pricing spikes; normalization follows once supply returns.
• Regulatory changes: antimicrobial policy shifts can reduce formulary share even when infections persist.

Projection range logic (high-level)

• Base case: modest decline or flat revenue in mature markets due to price compression offset by stable procurement volumes.
• Downside case: sharper declines if formularies restrict sulfonamides due to resistance or stewardship tightening.
• Upside case: temporary gains from supply constraints or reclassification in certain public tender categories.

Because no jurisdictional sales dataset is provided here, a numeric forecast would be fabricated.

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Investment and business implications: what decisions should be made now?

If you are an R&D sponsor

• Expect low incremental patent-driven value unless you pursue:
  • A new formulation, new salt, or new dosing regimen with a distinct regulatory pathway and patentable claims; or
  • A new indication with robust clinical differentiation and a filing strategy tied to exclusivity (not provided in the request).

If you are a generic manufacturer

• Focus on:
  • Bioequivalence robustness and regulatory inspection readiness.
  • Cost-down at scale (API supply contracts, yield, yield variability control).
  • Tender discipline (pricing cadence aligned with competitor entry timing).

If you are a distributor or payer-facing buyer

• Treat sulfadiazine as a procurement category with:
  • Clear substitution rules,
  • Manufacturer qualification requirements,
  • And inventory risk management for tender cycles.

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Key Takeaways

• Sulfadiazine’s modern commercial profile is legacy and generic, with limited evidence of molecule-specific late-stage proprietary clinical development.
• A high-precision clinical trials update and market forecast require indication- and scope-specific filtering; without it, any numeric claims would be unreliable.
• Business value centers on generic execution (manufacturing, regulatory, procurement) rather than on trial-driven pipeline upside.

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FAQs

1) Is sulfadiazine currently in late-stage clinical trials?

No confirmed late-stage, molecule-led proprietary development signal is available in the provided input context.

2) What is the primary business risk for sulfadiazine revenue?

Price compression and formulary tightening tied to stewardship and resistance patterns.

3) What drives sulfadiazine demand in public procurement?

Continuity of guideline acceptance and tender placement by therapeutic category.

4) Can sulfadiazine generate patent-protected revenue?

Not typically as a legacy antibacterial unless paired with a patentable formulation, method, or new use strategy (not specified here).

5) What is the most important competitive lever for manufacturers?

Stable supply at qualified quality levels and tender-linked pricing discipline.

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References

[1] U.S. National Library of Medicine. ClinicalTrials.gov. https://clinicaltrials.gov/
[2] World Health Organization. Antimicrobial resistance and stewardship resources. https://www.who.int/health-topics/antimicrobial-resistance
[3] FDA. Drugs@FDA (sulfadiazine entries and approvals). https://www.accessdata.fda.gov/scripts/cder/daf/