Summary
Naproxen has reached the approved stage (maximum clinical phase 4) for at least one indication, so its use in Ankylosing Spondylitis / Axial Spondyloarthropathy would be drug repurposing rather than first-in-human development. This does not mean it is approved for Ankylosing Spondylitis / Axial Spondyloarthropathy. ClinicalTrials.gov lists 4 registered trials linking Naproxen to Ankylosing Spondylitis / Axial Spondyloarthropathy: 3 have completed; 1 is terminated, withdrawn, suspended or of unknown status. The most advanced is Phase 3 (NCT01208207). It plans or enrolled 1015 participants. Registration activity spans 2006 to 2015. The literature layer holds 9 publications for this pair: 4 Cochrane reviews and 5 clinical trial publications. Publication years run from 2004 to 2019. Because at least one synthesis-level source exists (systematic review, meta-analysis or Cochrane review), this pair has been assessed beyond single studies, although the synthesis may concern a different indication.
The RepurpOS disease-intelligence file for Ankylosing Spondylitis ranks 151 candidate therapeutics from Open Targets, ChEMBL, DGIdb and PubMed; only a minority carry direct clinical evidence, and this page covers one of those. Spontaneous remission context recorded for the condition: Progressive structural damage (sacroiliac fusion, syndesmophytes) in majority without treatment; spontaneous radiographic remission essentially zero; ~10% achieve clinical remission without anti-inflammatory therapy.
Evidence table
| Evidence tier | A · Strong |
|---|---|
| Evidence score | 64.0 (trials 14.0, literature 30.0, tier 15, approved bonus 5.0) |
| Registered trials | 4 total: 0 recruiting, 0 active / not yet recruiting, 3 completed, 1 other |
| Linked publications | 9 (5 clinical trial publications, 4 Cochrane reviews) |
| Agent type | Drug (Small molecule) |
| Development stage (any indication) | Approved |
| Mechanism / class | Not recorded |
| Data sources | Open Targets, ChEMBL |
How the evidence score is calculated
- Each registered trial scores by status (recruiting / active / enrolling 3, completed 2.5, not yet recruiting 2, unknown 1, terminated / withdrawn / suspended 0.5) plus a phase bonus (phase 3-4 +2, phase 2 +1, phase 1 +0.5). The trial component is capped at 30.
- Each literature item scores by design (Cochrane review 5, meta-analysis 4, systematic review 3, RCT 3, clinical trial publication 2, curated reference 1.5, other PubMed record 1). The literature component is capped at 30.
- The existing evidence tier adds 15 (A / Strong), 10 (B / Moderate), 5 (C / Preliminary) or 0 (D / Anecdotal).
- Agents approved for any indication (max clinical phase 4) add 5, because an approved agent has an established safety profile that lowers the barrier to repurposing trials.
- The score ranks what has been studied, not what works. It does not read effect sizes or directions of effect.
Registered clinical trials
| NCT ID | Title | Status | Phase | Enrolment |
|---|---|---|---|---|
| NCT00844805 | Infliximab for Treatment of Axial Spondyloarthritis (P05336 AM1) 2009 | completed | Phase 3 | 158 |
| NCT01208207 | A Two-Part 26-Week Study of Etoricoxib as Treatment for Ankylosing Spondylitis (AS) (MK-0663-108) 2010 | completed | Phase 3 | 1,015 |
| NCT00367211 | Study to Evaluate the Incidence of Gastric Ulcers Following Administration of Either PN 200 or Naproxen in Subjects Who Are at Risk for Developing NSAID-Associated Ulcers. 2006 | completed | Phase 3 | 400 |
| NCT02293681 | An Observational Study of Infliximab in Participants Suffering From Ankylosing Spondylitis With Hip Involvement 2015 | terminated | Not applicable | 76 |
Published literature
- Clinical trial publication The safety and efficacy of Guluronic acid (G2013) in ankylosing spondylitis: A randomized controlled parallel clinical trialNazeri S, Jamshidi AR, Mahmoudi M et al. · Pharmacological reports : PR · 2019 · PMID 31003148
- Clinical trial publication Evaluation of the efficacy and safety of β-d-mannuronic acid in patients with ankylosing spondylitis: A 12-week randomized, placebo-controlled, phase I/II clinical trialFattahi MJ, Jamshidi AR, Mahmoudi M et al. · International immunopharmacology · 2018 · PMID 29127910
- Clinical trial publication The effects of β-D-mannuronic acid (M2000), as a novel NSAID, on COX1 and COX2 activities and gene expression in ankylosing spondylitis patients and the murine monocyte/macrophage, J774 cell lineJafarnezhad-Ansariha F, Yekaninejad MS, Jamshidi AR et al. · Inflammopharmacology · 2018 · PMID 28819782
- Clinical trial publication A randomized, clinical trial to assess the relative efficacy and tolerability of two doses of etoricoxib versus naproxen in patients with ankylosing spondylitisBalazcs E, Sieper J, Bickham K et al. · BMC musculoskeletal disorders · 2016 · PMID 27737664
- Clinical trial publication Partial remission in ankylosing spondylitis and non-radiographic axial spondyloarthritis in treatment with infliximab plus naproxen or naproxen alone: associations between partial remission and baseline disease characteristicsSieper J, Rudwaleit M, Lenaerts J et al. · Rheumatology (Oxford, England) · 2016 · PMID 27411482
- Cochrane review Non-steroidal anti-inflammatory drugs (NSAIDs) for axial spondyloarthritis (ankylosing spondylitis and non-radiographic axial spondyloarthritis)Kroon FP, van der Burg LR, Ramiro S et al. · The Cochrane database of systematic reviews · 2015 · PMID 26186173
- Cochrane review Methotrexate for ankylosing spondylitisChen J, Veras MM, Liu C et al. · The Cochrane database of systematic reviews · 2013 · PMID 23450553
- Cochrane review Methotrexate for ankylosing spondylitisChen J, Liu C, Lin J · The Cochrane database of systematic reviews · 2006 · PMID 17054209
- Cochrane review Methotrexate for ankylosing spondylitisChen J, Liu C · The Cochrane database of systematic reviews · 2004 · PMID 15266537
Mechanism and notes
No mechanism of action is recorded for this pair in the source databases.
OSMF's existing evidence tier for this pair is A (Strong), derived from the strength of the disease association recorded in Open Targets and ChEMBL. The tier describes how well the drug-disease link is documented, not how well the drug works.
Frequently asked questions
Is Naproxen approved for Ankylosing Spondylitis / Axial Spondyloarthropathy?
Naproxen has reached the approved stage (maximum clinical phase 4) for at least one indication, so its use in Ankylosing Spondylitis / Axial Spondyloarthropathy would be drug repurposing rather than first-in-human development. This does not mean it is approved for Ankylosing Spondylitis / Axial Spondyloarthropathy. Approval status for the specific indication should always be confirmed with the relevant regulator and prescribing information.
Is Naproxen in clinical trials for Ankylosing Spondylitis / Axial Spondyloarthropathy?
ClinicalTrials.gov lists 4 registered trials linking Naproxen to Ankylosing Spondylitis / Axial Spondyloarthropathy: 3 have completed; 1 is terminated, withdrawn, suspended or of unknown status. The most advanced is Phase 3 (NCT01208207). It plans or enrolled 1015 participants. Registration activity spans 2006 to 2015.
What does the evidence show for Naproxen in Ankylosing Spondylitis / Axial Spondyloarthropathy?
Naproxen has both completed registered trials and synthesis-level publications linked to Ankylosing Spondylitis / Axial Spondyloarthropathy. That is the strongest profile in this database, but the summaries here do not extract effect sizes, so read the linked reviews for direction and magnitude of benefit. OSMF's existing evidence tier for this pair is A (Strong), derived from the strength of the disease association recorded in Open Targets and ChEMBL. The tier describes how well the drug-disease link is documented, not how well the drug works.
Cite this page
Data: ClinicalTrials.gov, PubMed, Open Targets, ChEMBL, DGIdb and the OSMF therapeutic agent database. Last updated 2026-07-05. Page built 2026-10-07.