Last Updated: September 25, 2026

CLINICAL TRIALS PROFILE FOR SULFAMETHOXAZOLE AND TRIMETHOPRIM SINGLE STRENGTH


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505(b)(2) Clinical Trials for SULFAMETHOXAZOLE AND TRIMETHOPRIM SINGLE STRENGTH

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 Combination NCT03431168 ↗ A Novel Regimen to Prevent Malaria and STI in Pregnant Women With HIV Active, not recruiting University of Alabama at Birmingham Phase 2 2018-03-07 More than 3 billion people worldwide are at risk of acquiring malaria and pregnant women living with HIV in Africa are at particular risk. An effective prophylaxis regimen capable of preventing malaria and other common perinatal infections would have great potential to improve adverse birth outcomes. The purpose of this randomized controlled trial is to evaluate a new combination prophylaxis regimen in pregnant women with HIV in Cameroon to determine its efficacy and safety.
OTC NCT05055544 ↗ Bearberry in the Treatment of Cystitis Not yet recruiting University of Pecs N/A 2021-10-01 The goal of this study is to assess the efficacy of bearberry in uncomplicated cystitis. Uncomplicated cystitis is a disease related to the infection of the urinary bladder. Typical symptoms are dysuria, urinary urgency, and frequent voiding of small volumes. Urinary tract infections are frequent in women, usually treated with antibiotics, since the disease is usually caused by bacteria. Fosfomycin is a frequently used antibiotic for the treatment of uncomplicated cystitis. This medicine is typically prescribed by MDs. However, since uncomplicated cystitis is quite frequent, not all patients visit the doctor when experiencing the symptoms of this disease. The use of over-the-counter products (medicines and food supplements) to alleviate the symptoms is common. One of the most frequently used medicinal plants for this purpose is bearberry. Bearberry is a medicinal plant traditionally used for the treatment of cystitis. Its use is accepted by the European Medicine Agency as traditional herbal medicinal product for relief of symptoms of mild recurrent lower urinary tract infections such as burning sensation during urination and/or frequent urination in women. Although the experience gained during the traditional use and the laboratory experiments support the supposed beneficial effect of bearberry, its clinical efficacy has not been confirmed in well-designed clinical trials in comparison with standard antibiotic therapy. In this study, the efficacy of bearberry will be assessed in comparison with fosfomycin. Premenopausal women experiencing the symptoms of uncomplicated cystitis will be randomly divided into two groups. Since it will be a double-blind trial, neither the participants nor the experimenters will know who is receiving a particular treatment. In group A, patients will receive a single dose of fosfomycin powder dissolved in water and 2 placebo tablets three times a day for 7 days. In group B, patients will receive a single dose of placebo powder dissolved in water and 2 bearberry tablets three times a day for 7 days. At the beginning of the study (day 0) and on day 7, patients will be asked to fill in a questionnaire concerning their symptoms. At the same times, urine specimens will be collected to inspect the presence of bacteria in the urine. The primary goal of the trial is to assess the improvement of symptoms of uncomplicated cystitis after 7 days of treatment with the intention to analyze whether treatment with bearberry is at least as effective as fosfomycin therapy is. This will be achieved by using a validated questionnaire (Acute Cystitis Symptom Score). The presence of bacteria in urine and the frequency and severity of side effects will also be recorded and compared. During a 90-days follow-up of this study, the recurrence of urinary tract infections will be analyzed. This study will deliver important data on the efficacy and safety of bearberry in the treatment of uncomplicated cystitis.
>Trial Type >Trial ID >Title >Status >Phase >Start Date >Summary

All Clinical Trials for SULFAMETHOXAZOLE AND TRIMETHOPRIM SINGLE STRENGTH

Trial ID Title Status Sponsor Phase Start Date Summary
NCT00000640 ↗ A Phase III Comparative Study of Dapsone / Trimethoprim and Clindamycin / Primaquine Versus Sulfamethoxazole / Trimethoprim in the Treatment of Mild-to-Moderate PCP in Patients With AIDS Completed Glaxo Wellcome Phase 3 1969-12-31 To evaluate the effectiveness of two oral treatments for mild to moderate Pneumocystis carinii pneumonia (PCP): dapsone/trimethoprim or clindamycin/primaquine as compared to a standard treatment program of sulfamethoxazole/trimethoprim (SMX/TMP) to assess the tolerance of these two alternative treatments as compared to the standard treatment of SMX/TMP. Per 09/09/92 amendment, to assess the efficacy and tolerance of these two alternative treatments in patients who are intolerant to SMX/TMP. The type of treatment being studied has the advantages of wide applicability throughout the world (including developing countries) and low cost. An oral treatment is more accessible to patients than drugs given by injection or by inhalation.
NCT00000640 ↗ A Phase III Comparative Study of Dapsone / Trimethoprim and Clindamycin / Primaquine Versus Sulfamethoxazole / Trimethoprim in the Treatment of Mild-to-Moderate PCP in Patients With AIDS Completed Jacobus Pharmaceutical Phase 3 1969-12-31 To evaluate the effectiveness of two oral treatments for mild to moderate Pneumocystis carinii pneumonia (PCP): dapsone/trimethoprim or clindamycin/primaquine as compared to a standard treatment program of sulfamethoxazole/trimethoprim (SMX/TMP) to assess the tolerance of these two alternative treatments as compared to the standard treatment of SMX/TMP. Per 09/09/92 amendment, to assess the efficacy and tolerance of these two alternative treatments in patients who are intolerant to SMX/TMP. The type of treatment being studied has the advantages of wide applicability throughout the world (including developing countries) and low cost. An oral treatment is more accessible to patients than drugs given by injection or by inhalation.
NCT00000640 ↗ A Phase III Comparative Study of Dapsone / Trimethoprim and Clindamycin / Primaquine Versus Sulfamethoxazole / Trimethoprim in the Treatment of Mild-to-Moderate PCP in Patients With AIDS Completed National Institute of Allergy and Infectious Diseases (NIAID) Phase 3 1969-12-31 To evaluate the effectiveness of two oral treatments for mild to moderate Pneumocystis carinii pneumonia (PCP): dapsone/trimethoprim or clindamycin/primaquine as compared to a standard treatment program of sulfamethoxazole/trimethoprim (SMX/TMP) to assess the tolerance of these two alternative treatments as compared to the standard treatment of SMX/TMP. Per 09/09/92 amendment, to assess the efficacy and tolerance of these two alternative treatments in patients who are intolerant to SMX/TMP. The type of treatment being studied has the advantages of wide applicability throughout the world (including developing countries) and low cost. An oral treatment is more accessible to patients than drugs given by injection or by inhalation.
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.
>Trial ID >Title >Status >Phase >Start Date >Summary

Clinical Trial Conditions for SULFAMETHOXAZOLE AND TRIMETHOPRIM SINGLE STRENGTH

Condition Name

Condition Name for SULFAMETHOXAZOLE AND TRIMETHOPRIM SINGLE STRENGTH
Intervention Trials
HIV Infections 36
Pneumonia, Pneumocystis Carinii 27
Urinary Tract Infections 10
Urinary Tract Infection 8
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Condition MeSH

Condition MeSH for SULFAMETHOXAZOLE AND TRIMETHOPRIM SINGLE STRENGTH
Intervention Trials
HIV Infections 39
Infections 39
Pneumonia 38
Infection 34
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Clinical Trial Locations for SULFAMETHOXAZOLE AND TRIMETHOPRIM SINGLE STRENGTH

Trials by Country

Trials by Country for SULFAMETHOXAZOLE AND TRIMETHOPRIM SINGLE STRENGTH
Location Trials
United States 402
Canada 16
China 16
France 16
Mexico 7
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Trials by US State

Trials by US State for SULFAMETHOXAZOLE AND TRIMETHOPRIM SINGLE STRENGTH
Location Trials
California 33
New York 25
Illinois 24
Pennsylvania 20
Ohio 20
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Clinical Trial Progress for SULFAMETHOXAZOLE AND TRIMETHOPRIM SINGLE STRENGTH

Clinical Trial Phase

Clinical Trial Phase for SULFAMETHOXAZOLE AND TRIMETHOPRIM SINGLE STRENGTH
Clinical Trial Phase Trials
PHASE4 9
PHASE2 2
PHASE1 1
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Clinical Trial Status

Clinical Trial Status for SULFAMETHOXAZOLE AND TRIMETHOPRIM SINGLE STRENGTH
Clinical Trial Phase Trials
Completed 87
Recruiting 19
Terminated 14
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Clinical Trial Sponsors for SULFAMETHOXAZOLE AND TRIMETHOPRIM SINGLE STRENGTH

Sponsor Name

Sponsor Name for SULFAMETHOXAZOLE AND TRIMETHOPRIM SINGLE STRENGTH
Sponsor Trials
National Institute of Allergy and Infectious Diseases (NIAID) 31
Glaxo Wellcome 8
National Cancer Institute (NCI) 7
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Sponsor Type

Sponsor Type for SULFAMETHOXAZOLE AND TRIMETHOPRIM SINGLE STRENGTH
Sponsor Trials
Other 189
NIH 52
Industry 41
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Sulfamethoxazole and Trimethoprim single-strength (TMP-SMX SS) clinical trials update, market analysis, and projection

Last updated: July 27, 2026

Executive summary

  • Clinical trials: This active ingredient combination (SMX/TMP, fixed-dose) is largely in late-stage or bioequivalence-oriented development in the US due to the long-standing, off-patent status of the core API combination. Active trial activity is typically concentrated in new formulations (e.g., oral suspensions, tablets, or specialty dispersible forms), pediatric dosing studies, pharmacokinetic/biopharmaceutics, and comparative efficacy/safety trials in infectious disease indications rather than discovery-stage drug development.
  • Market: TMP-SMX SS remains a high-volume, low-cost oral antibiotic in the US and other regulated markets. Demand is driven by broad community and institutional use in UTI, respiratory infections, and skin/soft-tissue infections, and by niche high-use protocols (including prophylaxis in selected immunocompromised populations).
  • Projection: Near-to-mid-term growth is expected to track infectious disease prescribing dynamics, resistance patterns, and manufacturer mix, with incremental revenue upside primarily from formulation launches, supply continuity, and volume retention rather than major pricing power.
  • IP exposure: Core combination and most method-of-use claims are expired or near-expired; market access is dominated by ANDA and 505(b)(2) pathways, plus product-specific formulation/packaging patents where still present.

What is sulfamethoxazole and trimethoprim single strength (SMX/TMP SS) and how is it used clinically?

Quick answer: TMP-SMX single strength is the standard fixed-dose oral regimen combining sulfamethoxazole with trimethoprim for bacterial infections, with indications varying by label and region.

Common label-style uses (commercially relevant)

TMP-SMX (oral) is used across many markets for:

  • Urinary tract infections (especially when susceptible organisms are involved)
  • Skin and soft tissue infections
  • Respiratory infections in susceptible settings
  • Pneumocystis jirovecii pneumonia (PJP) prophylaxis in immunocompromised patients (often via separate dosing regimens, sometimes with “double strength” marketed labeling; single strength may be used for prophylaxis protocols depending on country/label)

Key clinical determinants of demand

  • Local susceptibility profiles (TMP-SMX susceptibility for uropathogens and skin pathogens)
  • Prescribing substitution vs fluoroquinolones, doxycycline, beta-lactams
  • MRSA and resistance patterns in skin infections
  • Renal function constraints and safety monitoring that shape utilization in elderly and CKD populations

What clinical trial updates exist for TMP-SMX single strength in 2024-2026?

Quick answer: Development activity is typically not dominated by novel mechanisms but by trial work that supports regulatory filings and optimized use for specific populations and formulations.

Trial categories that keep showing up for TMP-SMX products

  1. Bioequivalence and bridging trials

    • Focus: PK comparability of new generics, pediatric formulations, and updated manufacturing processes.
    • Output: ANDA or 505(b)(2) support.
  2. Population-focused studies

    • Pediatric dosing tolerability and weight-based adjustments
    • Renal impairment and hydration/monitoring protocols
    • Outcomes in older adults where adverse event management drives adherence
  3. Comparative effectiveness and safety

    • Trials that compare TMP-SMX versus alternatives in specific infection syndromes (e.g., UTI or skin infections)
    • Endpoints: clinical cure, microbiologic eradication, safety and discontinuation rates

What the absence of “new MOA” trials implies for pipeline

With TMP-SMX’s long market presence, the pipeline effect is mostly:

  • Product lifecycle management for generics and reformulations
  • Manufacturing and compliance-driven trials
  • Incremental label expansions in narrower cohorts rather than broad first-in-class expansions

Which indications are most likely to drive future clinical and commercial demand for TMP-SMX SS?

Quick answer: UTIs and skin/soft-tissue infections are the most consistent volume indicators; prophylaxis remains structurally important where TMP-SMX is preferred.

Indication-level demand drivers

  • UTI: TMP-SMX remains a common option in susceptibility-guided practice. Demand is sensitive to resistance rates.
  • Skin/soft-tissue infections: Local resistance and empiric prescribing habits shape share.
  • Prophylaxis in immunocompromised care: Even if single strength is not always the dominant marketed dose form, protocols keep baseline demand anchored in specialized care pathways.

How does TMP-SMX single strength compare with double strength, and does that affect market projection?

Quick answer: Double strength (DS) often carries higher per-day active ingredient exposure for therapeutic regimens and some prophylaxis protocols, while single strength is generally used for different dosing schedules and certain label-specific use cases.

Commercial impact of SS vs DS

  • Share shift risk: If DS is preferred for high-intensity protocols, SS volume can erode where prescribers move to DS.
  • Formulation substitution: If DS supply is constrained or certain generics are discontinued, SS can capture replacement demand.
  • Pediatric dosing: SS can be favored in weight-based regimens and where titration is easier.

What patents protect sulfamethoxazole and trimethoprim single strength and how strong is the patent estate?

Quick answer: The active ingredient combination is broadly off-patent for core composition and long-standing therapeutic uses. Remaining IP is usually product-specific: formulation, manufacturing, polymorph/process, or packaging/label claims where any still exist.

Practical IP landscape for business planning

  • Core API combination: Combination and use patents are largely expired in major jurisdictions.
  • Focus for residual exclusivity:
    • Novel formulations (e.g., taste-masked suspensions)
    • Pediatric-specific dosing forms
    • Process improvements that are tied to specific manufacturing know-how or unit operation changes

Litigation/IP barriers that matter commercially

  • For generic entrants, the barriers are usually regulatory and supply-chain rather than long, enforceable primary composition patents.
  • Where any remaining patents exist, they are typically narrow and can be designed around by formulation or process changes.

What is the Orange Book status of TMP-SMX single strength in the US?

Quick answer: For TMP-SMX oral single strength products, the Orange Book typically shows multiple approved ANDAs for equivalent strengths and dosage forms with expired listed patents for the active ingredient combination.

How Orange Book status shapes market forecasts

  • Rapid generic turnover: many products with overlapping approvals
  • Limited pricing power: competitive pressure compresses realized pricing
  • Entry timing driven by 180-day exclusivity mechanics (if applicable), product-specific patents, and manufacturing approvals

When does TMP-SMX single strength lose exclusivity and how fast can generics launch?

Quick answer: For core combination products, exclusivity is effectively already passed in major markets. New launches typically occur via routine ANDA/505(b)(2) processes rather than waiting on major exclusivity cliffs.

Generic launch dynamics that still impact projections

  • Regulatory facility readiness: ANDA approval depends on product-specific chemistry and controls
  • Supply constraints: if a reference or incumbent product faces manufacturing disruption, entrants can gain short-term share regardless of patent status
  • Labeling and dosage form fit: SS tablet vs suspension vs other presentations can shift share even when APIs are the same

How many ANDAs cover TMP-SMX single strength and which manufacturers dominate?

Quick answer: Coverage is high in the US because TMP-SMX is an established generic with multiple approved manufacturers across tablet and suspension formats.

Dominant business reality

  • Fragmented supplier base across large generic firms and mid-size manufacturers
  • Price competition drives share concentration around supply reliability and formulary inclusion
  • Contracting (GPO/wholesaler) often determines realized market share more than clinical positioning

(Note: a manufacturer-by-manufacturer ORCHD listing table is not included here because precise Orange Book counts and assignee-level product listings require direct docket-level retrieval.)


What Paragraph IV challenges or patent litigation affect TMP-SMX single strength?

Quick answer: Because core patents are largely expired, Paragraph IV litigation is not a recurring driver for this drug class at the same frequency as in newer branded compounds.

Where litigation still can appear

  • Narrow formulation/process patents tied to a specific product
  • Disputes related to specific listed patents on a reference product
  • Issues tied to labeling carve-outs and controlled-release or pediatric formulation claims (less common for TMP-SMX than for novel modalities)

What settlement agreements or exclusivity deals matter for TMP-SMX SS?

Quick answer: Settlement-driven market shifts are typically less influential than for newer brand products because the competitive baseline is already generic.

Commercial effect where settlements occur

  • Limited-duration share adjustments around a particular strength or dosage form
  • Incumbent protection windows are usually product- and patent-specific, not class-wide

Which FDA pathway is most common for TMP-SMX single strength generics: ANDA or 505(b)(2)?

Quick answer: ANDA is the most common pathway for TMP-SMX SS because it is an established, off-patent active ingredient combination.

What pushes use of 505(b)(2) in practice

  • Meaningful formulation changes that require bridge data beyond standard bioequivalence
  • Modified release, reformulation with improved palatability/tolerability, or alternative excipient systems
  • Certain pediatric formulation approaches

What formulation patents are likely relevant for TMP-SMX single strength?

Quick answer: When formulation IP exists, it tends to focus on taste masking, improved dissolution, stability, and pediatric-friendly delivery rather than on new active ingredients.

Formulation areas that can generate residual IP

  • Taste masking and palatability improvement
  • Stability improvement across temperature and humidity ranges
  • Suspension redispersibility and shelf-life extension
  • Unit dose accuracy and measuring device compatibility

What manufacturing/IP barriers can delay generic entry for TMP-SMX SS?

Quick answer: Operational barriers dominate: facility capability, validated dissolution/bioequivalence, impurity control, and consistent batch performance.

Key technical bottlenecks

  • Impurity profiling and control across multiple suppliers
  • Consistent mixing and granulation where applicable
  • QA release time and sterility is not relevant (oral drug), but microbial control and stability testing are

Market analysis: how large is TMP-SMX single strength and what drives revenue?

Quick answer: TMP-SMX SS is a large-volume but low-margin antibiotic market segment with revenue highly sensitive to contracting, pricing pressure, and dispensing trends.

Revenue drivers that matter

  • Utilization volume in outpatient and inpatient settings
  • Formulary position and payer policy
  • Generic price compression and wholesaler/GPO rebate dynamics
  • Resistance patterns that influence whether prescribers keep TMP-SMX in empiric and susceptibility-guided workflows

Revenue downside risks

  • Increased shift away from TMP-SMX due to resistance
  • Safety concerns affecting adherence or provider comfort in vulnerable populations
  • Supply disruptions that cause short-term substitution to alternatives

Projection: what is the 3-to-7 year outlook for TMP-SMX SS volume and value?

Quick answer: Over 3 to 7 years, expectations are stable-to-slightly growing volumes with flat-to-declining net pricing, leading to modest value growth unless formulation-based premiumization or supply-driven share gains occur.

Base-case projection mechanics (no brand premium)

  • Volume tracks infection incidence and prescribing patterns
  • Value growth depends on net price stability, which is dominated by:
    • Generic competition intensity
    • Contract renewals
    • National shortages and their duration

Upside scenarios

  • Product portfolio expansion (SS tablets and pediatric-friendly liquids)
  • Improved tolerability formulations that earn formulary preference
  • Incumbent supply issues that create “sticky” channel relationships for available SKUs

Downside scenarios

  • Higher regional resistance leading to substitution
  • Regulatory or manufacturing setbacks that force fewer suppliers into the market

Which segments could see faster growth within TMP-SMX SS?

Quick answer: Growth is most plausible in pediatric-optimized formulations, stable shelf-life and reconstitution-friendly suspensions, and contract-driven uptake where supply reliability is critical.

Segment-level focus

  • Pediatric dosing convenience SKUs (measuring device, improved palatability)
  • Hospital formulary packs that reduce medication errors
  • Distribution-ready presentations that reduce backorders

How does TMP-SMX SS compete with other oral antibiotics in UTI and skin infections?

Quick answer: TMP-SMX competes with:

  • Beta-lactams (amoxicillin-clavulanate, cephalosporins)
  • Doxycycline for selected skin infections
  • Fluoroquinolones in susceptibility-guided or higher-acuity cases
  • Macrolides in respiratory contexts (indication-dependent)
  • Others depending on resistance and local stewardship

Competitive share drivers

  • Formulary placement
  • Expected susceptibility rates
  • Provider safety profile comfort and monitoring burden
  • Cost per course including adherence likelihood

Key Takeaways

  • TMP-SMX single strength is an off-patent, high-competition antibiotic segment where clinical development is dominated by formulation and biopharmaceutics rather than novel mechanisms.
  • Market performance is driven by prescribing volume, resistance-guided selection, and generic contracting more than by exclusivity or blockbuster lifecycle shifts.
  • The 3-to-7 year value outlook is modest, with net revenue growth likely coming from share gains via product availability and formulation improvements, while pricing remains pressured by generics.
  • Business strategy should prioritize dosage form portfolio, supply continuity, regulatory-ready manufacturing, and segment-specific differentiation (pediatric and stability-focused).

FAQs

  1. Are there any new clinical endpoints or safety concerns emerging for TMP-SMX that change prescribing?
  2. Do resistance patterns increase or decrease TMP-SMX single strength use in UTIs by region?
  3. How do generic substitutions in the US typically affect TMP-SMX SS pricing and channel share?
  4. What formulation attributes most often determine success for new generic pediatric TMP-SMX products?
  5. Can 505(b)(2) be advantageous for reformulating TMP-SMX single strength compared with ANDA-only strategies?

References

  1. FDA. “Drugs@FDA” database. U.S. Food and Drug Administration.
  2. FDA. “Orange Book: Approved Drug Products with Therapeutic Equivalence Evaluations.” U.S. Food and Drug Administration.
  3. ClinicalTrials.gov. “Sulfamethoxazole and Trimethoprim” search results. U.S. National Library of Medicine.

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