Sulfasalazine

證據等級: L5

預測適應症: 10 個

Sulfasalazine: From Rheumatoid Arthritis to Osteoarthritis

One-Sentence Summary

Sulfasalazine is a long-established disease-modifying antirheumatic drug (DMARD), well known for treating rheumatoid arthritis and inflammatory bowel disease. The TxGNN model predicts it may also be effective for Osteoarthritis, and unlike the model’s top-ranked candidates (mostly ultra-rare genetic syndromes with zero supporting evidence), this indication is backed by 2 clinical trials and 20 publications — making it the most credible repurposing signal in this evidence pack.

Note on selection: Among the 10 TxGNN-predicted indications, ranks #1–4, #6–7, #9–10 are rare genetic/developmental syndromes (e.g., brachydactyly-syndactyly syndrome, WHIM syndrome) with no clinical trials or literature at all (Evidence Level L5, recommendation = Hold) — likely model noise rather than actionable signal. This report focuses on Osteoarthritis (rank #5), the highest-ranked candidate with actual clinical and mechanistic evidence.

Quick Overview

Item	Content
Original Indication	Rheumatoid Arthritis / Ulcerative Colitis (well-established clinical use; no formal TFDA license record available in this evidence pack)
Predicted New Indication	Osteoarthritis
TxGNN Prediction Score	99.64%
Evidence Level	L3
US Market Status	Not Marketed
Number of NDAs	0
Recommended Decision	Hold

Why is This Prediction Reasonable?

Currently, detailed mechanism of action data is not available (flagged as a High-severity data gap — MOA not yet retrieved from DrugBank API). Based on known information, sulfasalazine is a combination molecule (sulfapyridine + 5-aminosalicylic acid) belonging to the DMARD class, with proven efficacy in rheumatoid arthritis and inflammatory bowel disease through anti-inflammatory and immunomodulatory action.

Multiple preclinical studies in this evidence pack suggest a mechanistic bridge to osteoarthritis: sulfasalazine appears to inhibit NF-κB signaling and pro-inflammatory cytokine (IL-1β/TNF-α)-induced cartilage degradation. In animal and ex-vivo cartilage models, it reduced proteoglycan and collagen loss and downregulated cartilage-degrading enzymes (MMPs/ADAMTS), suggesting chondroprotective potential.

However, this mechanistic evidence is largely an extension of rheumatoid arthritis-focused research rather than purpose-built osteoarthritis drug development. No trial in this evidence pack directly tests sulfasalazine as a monotherapy intervention in an OA patient population — the two identified clinical trials involve other drugs (tofacitinib/MTX, CRx-102) in adjacent rheumatic disease contexts. The prediction is therefore mechanistically plausible but clinically unproven.

Clinical Trial Evidence

Trial Number	Phase	Status	Enrollment	Key Findings
NCT03975790	N/A	Completed	479	Retrospective claims-database cohort comparing tofacitinib (Xeljanz) + MTX withdrawal vs. continuation in RA patients; sulfasalazine is not the intervention drug — relevance graded low (C)
NCT00551707	Phase 2	Completed	51	Placebo-controlled RCT of CRx-102 (dipyridamole + low-dose prednisolone) in active RA; sulfasalazine not directly tested — relevance graded moderate (B), disease population uncertain

Note: Neither trial directly evaluates sulfasalazine in an osteoarthritis population; both were captured via broader rheumatic-disease search overlap.

Literature Evidence

PMID	Year	Type	Journal	Key Findings
29548914	2018	Preclinical (in vitro/animal)	Int J Biol Macromol	Sulfasalazine-hyaluronic acid sustained-release system reduced inflammation and cartilage degradation in an MIA-induced rat OA model
26466556	2016	Preclinical (animal, ACLT+MMx)	J Orthop Res	Sulfasalazine attenuated cartilage destruction in a surgically-induced OA model via inhibition of the cystine/glutamate antiporter (system Xc−)
24329131	2014	Preclinical (chondrocyte proteomics)	Mod Rheumatol	Sulfasalazine and tofacitinib altered protein profiles of articular chondrocytes
19690126	2009	Preclinical (cartilage explant)	Rheumatology (Oxford)	Sulfasalazine blocked cytokine-stimulated release of proteoglycan/collagen fragments and downregulated MMPs/ADAMTS in cartilage explants
1673814	1991	In vitro pharmacology	Wien Klin Wochenschr	Sulfasalazine and metabolites inhibited leukotriene release from synovial tissue of OA, chondrocalcinosis, and RA patients
11478054	2001	Review	Hand Clin	Overview of pharmacologic treatment options across RA and OA
35958605	2022	Review	Front Immunol	Review of ferroptosis mechanisms across inflammatory arthritis subtypes including OA
9567207	1998	Review	Curr Opin Rheumatol	Broader update on rheumatic disease clinical trials, including RA and OA therapeutics

Note: All identified literature is preclinical, in vitro, or narrative review — no RCT or clinical outcome study of sulfasalazine specifically in OA patients was found.

US Market Information

Sulfasalazine currently has no license records in this evidence pack (market_status: 未上市, total_licenses: 0). No authorization data is available to tabulate.

Safety Considerations

Please refer to the package insert for safety information.

Note: This evidence pack flags TFDA warnings/contraindications as a Blocking data gap (DG001) — meaning a formal safety pre-assessment (S1) cannot proceed until the package insert is retrieved and parsed.

Conclusion and Next Steps

Decision: Hold

Rationale: Evidence for sulfasalazine in osteoarthritis is limited to preclinical/mechanistic studies (Evidence Level L3), with no RCT directly testing the drug in OA patients — the two available clinical trials involve different drugs and only tangential disease overlap. Combined with a Blocking severity data gap on TFDA safety labeling, this candidate cannot yet advance past the research-question stage.

To proceed, the following is needed:

TFDA package insert (warnings/contraindications) to resolve the Blocking safety data gap (DG001)
DrugBank MOA query to resolve the mechanism-of-action data gap (DG002)
A dedicated clinical trial or observational study testing sulfasalazine specifically in an OA patient population
Confirmation of regulatory/marketing status, since this drug currently shows 0 licenses in this jurisdiction
Disclaimer

This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.