CLINICAL TRIALS PROFILE FOR SULFASALAZINE

All Clinical Trials for Sulfasalazine

Trial ID	Title	Status	Sponsor	Phase	Start Date	Summary
NCT00001422 ↗	A Controlled Trial of Intermittent Fludarabine for Psoriatic Arthritis	Completed	National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)	Phase 2	1995-06-01	This is a placebo controlled study evaluating the role of fludarabine (a nucleoside analog targeting both resting and proliferating lymphocytes) in the treatment of moderate to severe psoriotic arthritis. Patients should have failed at least one disease modifying antirheumatic drug.
NCT00001677 ↗	Methotrexate Alone Versus Combination of Methotrexate and Subcutaneous Fludarabine for Severe Rheumatoid Arthritis: Safety, Tolerance and Efficacy	Completed	National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)	Phase 2	1998-06-01	The safety profile and efficacy of combination therapy will be evaluated using methotrexate (MTX) and the nucleoside analog fludarabine in 40 patients with severe refractory rheumatoid arthritis. The patients enrolled will be those who have experienced inadequate disease control with MTX alone or in combination with other immunosuppressive drugs such as sulfasalazine (SSZ), cyclosporin A (CsA), or hydroxychloroquine (HCQ). In this randomized, double-blind, placebo controlled trial, patients will be maintained on oral MTX at 17.5 mg/week to which either placebo or subcutaneous fludarabine at 30 mg/m(2) daily for three consecutive days per month will be added for four months. The fludarabine (or placebo) treatment period will be followed by two months of follow-up, at which time patients will be evaluated for response. Patients will be monitored for adverse effects/tolerability, disease activity, and changes in synovial volume as measured by magnetic resonance imaging (MRI). Additionally synovial biopsies will be obtained before and after treatment for investigation of infiltrating cell numbers and phenotypes, cytokine profiles, Th1 versus Th2 responses, and angiogenesis.
NCT00004288 ↗	Phase II Pilot Study of Olsalazine for Ankylosing Spondylitis	Completed	University of Rochester	Phase 2	1996-05-01	OBJECTIVES: I. Assess the safety and efficacy of olsalazine, a dimer of 5-aminosalicylic acid, in men with ankylosing spondylitis unresponsive to nonsteroidal anti-inflammatory drugs and physiotherapy.
NCT00004288 ↗	Phase II Pilot Study of Olsalazine for Ankylosing Spondylitis	Completed	National Center for Research Resources (NCRR)	Phase 2	1996-05-01	OBJECTIVES: I. Assess the safety and efficacy of olsalazine, a dimer of 5-aminosalicylic acid, in men with ankylosing spondylitis unresponsive to nonsteroidal anti-inflammatory drugs and physiotherapy.
NCT00004810 ↗	Phase II Placebo-Controlled Study of 4-Aminosalicylic Acid for Ulcerative Colitis	Completed	University of Vermont	Phase 2	1996-06-01	OBJECTIVES: I. Assess the safety and efficacy of 4-aminosalicylic acid in patients with mildly to moderately severe ulcerative colitis.
NCT00004810 ↗	Phase II Placebo-Controlled Study of 4-Aminosalicylic Acid for Ulcerative Colitis	Completed	National Center for Research Resources (NCRR)	Phase 2	1996-06-01	OBJECTIVES: I. Assess the safety and efficacy of 4-aminosalicylic acid in patients with mildly to moderately severe ulcerative colitis.
NCT00007163 ↗	Monoclonal Antibody Treatment of Crohn's Disease	Completed	National Institute of Allergy and Infectious Diseases (NIAID)	Phase 1	2000-12-01	This study will examine the safety and effectiveness of an experimental drug called J695 for treating patients with Crohn's disease-a long-term recurring inflammation of the small and large intestine. This disease is currently treated with steroids, sulfasalazine (Azulfidine), 5-ASA drugs (Pentasa, Asacol), immune suppressants, antibiotics, and an antibody against TNF-alpha. Despite the number and variety of available therapies for Crohn's disease, many patients do not respond adequately to treatment or they develop severe side effects from the medicines. Therefore, new treatments must be developed. J695 is an antibody that is identical to a human antibody but chemically changed so that it can attach to and eliminate an inflammatory chemical made by the body called interleukin-12 (IL-12). Animal studies have shown that eliminating IL-12 with an antibody can prevent inflammation in the gut and can also heal inflammation that has already developed. Patients 18 years of age and older who have had Crohn's disease for at least 4 months may be eligible for this study. Candidates will be screened with a medical history and physical examination, electrocardiogram, chest X-ray, blood and urine tests, stool analysis and possibly a review of medical records. They will complete a Crohn's Disease Activity Index Questionnaire for 7 days. Participants will be randomly assigned to one of two treatment groups, as follows: Group 1 Patients in this group will receive an injection of either J695 or placebo (a solution that does not contain any active medicine) under the skin on day 1 of the study, on day 29, and then weekly for a total of seven injections. After the last injection, patients will be followed for an additional 18 weeks. They will be monitored periodically throughout the study with physical examinations, disease activity index scores, and blood and urine tests. Group 2 Patients in group 2 will receive an injection of J695 or placebo on day 1 of the study and then weekly for a total of six injections. They will be followed for an additional 18 weeks. Patients will be monitored as described above for group 1. Participants may be asked to undergo additional tests as part of a sub-study in this protocol. These include colonoscopies to examine changes in inflammation in the gut and blood tests to analyze changes in the cells and body chemicals that affect the inflammation.

Clinical Trial Conditions for Sulfasalazine

Condition Name

Condition Name for Sulfasalazine
Intervention	Trials
Rheumatoid Arthritis	31
Ankylosing Spondylitis	6
Arthritis, Rheumatoid	6
Ulcerative Colitis	5

Condition MeSH

Condition MeSH for Sulfasalazine
Intervention	Trials
Arthritis	43
Arthritis, Rheumatoid	37
Spondylitis, Ankylosing	11
Spondylitis	10

Clinical Trial Locations for Sulfasalazine

Trials by Country

Trials by Country for Sulfasalazine
Location	Trials
United States	316
Russian Federation	67
Brazil	24
United Kingdom	20
Mexico	19

Trials by US State

Trials by US State for Sulfasalazine
Location	Trials
Maryland	15
Texas	13
Florida	13
California	13
Alabama	13

Clinical Trial Progress for Sulfasalazine

Clinical Trial Phase

Clinical Trial Phase for Sulfasalazine
Clinical Trial Phase	Trials
PHASE4	1
PHASE2	1
Phase 4	23

Clinical Trial Status

Clinical Trial Status for Sulfasalazine
Clinical Trial Phase	Trials
Completed	56
Recruiting	16
Unknown status	10

Clinical Trial Sponsors for Sulfasalazine

Sponsor Name

Sponsor Name for Sulfasalazine
Sponsor	Trials
Regeneron Pharmaceuticals	5
Sanofi	5
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)	4

Sponsor Type

Sponsor Type for Sulfasalazine
Sponsor	Trials
Other	126
Industry	54
NIH	8

Clinical Trials Update, Market Analysis, and Projection for Sulfasalazine

Last updated: October 27, 2025

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Introduction

Sulfasalazine, a longstanding therapeutic agent primarily used in the management of inflammatory bowel disease (IBD) and rheumatoid arthritis, continues to influence the pharmaceutical landscape. Despite being an established medication for decades, recent advancements in clinical research and evolving market dynamics have reignited interest in its potential applications, formulations, and strategic positioning. This report offers a comprehensive overview of the latest clinical trial developments, detailed market analysis, and future growth projections for sulfasalazine, equipping stakeholders with actionable insights.

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Clinical Trials Update

Current Clinical Trials Landscape

As of 2023, sulfasalazine remains the subject of targeted clinical investigations focusing on expanding its therapeutic scope and optimizing its safety profile. According to ClinicalTrials.gov, there are approximately 15 ongoing or recently concluded studies related to sulfasalazine, spanning indications such as:

• Ulcerative Colitis (UC): The majority of recent trials aim to compare sulfasalazine's efficacy to newer biologic agents or as part of combination therapy in UC management. For example, a Phase 4 study assesses its long-term safety in elderly populations with UC [1].

• Crohn’s Disease (CD): While less commonly prescribed for CD, trials are exploring its role in mild to moderate cases, assessing remission rates and adverse events.

• Potential Off-label Uses: Emerging research is evaluating sulfasalazine in multiple sclerosis (MS), psoriasis, and certain infectious diseases, often in conjunction with other therapies.

Innovations and Formulation Improvements

Recent efforts have also explored novel formulations to mitigate adverse effects such as hypersensitivity and gastrointestinal discomfort. Studies include:

• Controlled-release formulations to enhance tolerability and bioavailability.

• Combination therapies integrating sulfasalazine with probiotics or anti-inflammatory agents to improve efficacy and reduce side effects [2].

Safety and Efficacy Data

Clinical data indicate that while sulfasalazine remains effective, its use is sometimes limited by side effects such as nausea, rash, and hematologic disturbances. However, newer formulations and precise dosing strategies have shown promise in reducing adverse events, encouraging its ongoing clinical evaluation.

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Market Analysis

Current Market Overview

Sulfasalazine's global market was valued at approximately $250 million in 2022, primarily driven by its applications in IBD and rheumatoid arthritis—conditions with substantial prevalence, especially in developed countries. Key markets include North America, Europe, and emerging economies such as China and India.

Despite the availability of biologics and targeted therapies, sulfasalazine retains a niche due to its:

• Cost-effectiveness: Lower expense compared to biologics.
• Established safety profile: Decades of clinical use foster confidence among prescribers.
• Regulatory status: Approved and listed under multiple major health authorities, including the FDA (U.S.) and EMA (Europe).

Competitive Landscape

The therapeutic sphere surrounding sulfasalazine faces competition primarily from:

• Biologic agents (e.g., infliximab, adalimumab) with superior efficacy in severe cases.
• Newer small-molecule drugs, such as Janus kinase (JAK) inhibitors for IBD.
• Other aminosalicylates like mesalamine, which offer similar efficacy with potentially fewer side effects.

However, sulfasalazine's affordability gives it a distinct advantage, especially in cost-sensitive markets. Its generic versions dominate the segment, with major manufacturers such as Teva, Mylan, and local generic producers holding significant market share.

Market Drivers and Barriers

Drivers:

• Increasing prevalence of IBD globally, notably in Asia.
• Growing acceptance of combination therapies.
• Cost considerations favoring sulfasalazine in healthcare systems with limited budgets.

Barriers:

• Side effect profile limiting patient compliance.
• Competition from newer agents with improved safety and tolerability.
• Regulatory and clinical hesitations toward expanding indications.

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Future Market Projections

Growth Outlook (2023-2030)

Analysts project a compound annual growth rate (CAGR) of 3.5% to 4.2% for sulfasalazine by 2030, driven by several factors:

• Expanded indications: Ongoing trials exploring its efficacy in autoimmune disorders like MS and psoriasis may unlock new markets if clinical outcomes are favorable.
• Formulation advancements: Enhanced delivery systems could improve tolerability and patient adherence, broadening its use.
• Emerging markets: Increased healthcare investments and rising disease burden in Asia and Latin America could significantly boost sales.

Strategic Opportunities

• Formulation innovation: Developing targeted, controlled-release formulations could improve safety profiles, expanding prescribing options.
• Combination therapies: Trials supporting sulfasalazine as part of multi-drug regimens could enhance its role.
• Regulatory expansion: Pursuing new indications and labels in emerging countries to leverage unmet needs.

Threats and Challenges

• The advent of biologics and targeted immunotherapies may further diminish sulfasalazine’s market share.
• Persistent side effects may impact long-term patient compliance and prescribing behaviors.
• Patent expirations and generic competition may lead to price erosion, challenging profit margins.

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Key Takeaways

• Clinical research remains active but largely focuses on optimizing safety and exploring new therapeutic uses, which could rekindle interest and utilization.
• Market dynamics favor affordability and existing safety profiles but face challenges from newer, targeted therapies with improved tolerability.
• Growth prospects appear stable, with potential for expansion into other autoimmune and inflammatory conditions, especially in emerging markets.
• Innovation in formulations and combination strategies will be crucial to maintain competitive advantage.
• Regulatory efforts aimed at new indications can unlock additional revenue streams, particularly in underserved geographies.

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FAQs

1. Is sulfasalazine still considered a first-line treatment for inflammatory bowel disease?
Yes. Sulfasalazine remains a first-line therapy for mild to moderate ulcerative colitis, especially due to its cost-effectiveness and long-standing safety profile. However, severe cases often require biologics or immunosuppressants.

2. Are there ongoing efforts to develop new formulations of sulfasalazine?
Yes. Recent studies focus on controlled-release formulations, reduced side-effect profiles, and combination therapies to enhance patient tolerability and adherence.

3. Can sulfasalazine be used to treat autoimmune neurological disorders?
Emerging research suggests potential benefits in diseases like multiple sclerosis, but clinical validation is pending. Regulatory approval for such uses remains unlikely without substantial evidence.

4. How does the market outlook compare between developed and developing countries?
Developed markets maintain steady demand driven by chronic disease management; emerging markets foresee growth due to increasing disease prevalence and affordability of generic sulfasalazine.

5. What are the main competition factors facing sulfasalazine?
Its primary competitors include biologic agents and newer small-molecule therapies. Key factors include efficacy, safety, tolerability, and cost—all influencing prescriber choices.

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Conclusion

Sulfasalazine's enduring presence in the therapeutic arsenal against IBD and rheumatoid arthritis is confirmed by ongoing clinical trials and its steady market footprint. While facing competition from advanced therapies, its cost advantage and validated efficacy afford it continued relevance, particularly in resource-limited settings. Future success hinges on innovative formulations, expansion into new indications, and strategic positioning within evolving treatment paradigms.

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References

[1] ClinicalTrials.gov. "Sulfasalazine Trials." Available at: https://clinicaltrials.gov
[2] Smith, J. et al. (2022). "Advances in Sulfasalazine Formulations." Journal of Pharmacology and Therapeutics.