Tocilizumab
| Evidence Level: L2 | Predicted Indications: 10 |
Table of Contents
Tocilizumab: From Rheumatoid Arthritis to Ankylosing Spondylitis
One-Sentence Summary
Tocilizumab is an IL-6 receptor antibody originally used for rheumatoid arthritis, juvenile idiopathic arthritis, giant cell (temporal) arteritis and Castleman disease. The TxGNN model predicts it may be effective for ankylosing spondylitis, but the two Phase 3 placebo-controlled trials in this disease were both terminated, and the 18 publications retrieved are mostly reviews, with no confirmed efficacy result in the data compiled for this report.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Rheumatoid arthritis, juvenile idiopathic arthritis, spondyloarthropathy, temporal arteritis, Castleman disease (from the knowledge graph; no approved indication text is available in the Singapore licence records) |
| Predicted New Indication | Ankylosing spondylitis |
| TxGNN Prediction Score | 99.99% |
| Evidence Level | L2 |
| Singapore Market Status | ✓ Marketed |
| Number of Registrations | 2 |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Detailed mechanism of action data is not available in the data compiled for this report. Tocilizumab is known as a humanised monoclonal antibody against the interleukin-6 receptor (IL-6R). It is established in rheumatoid arthritis and juvenile idiopathic arthritis, and the literature describes use in giant cell arteritis.
IL-6 signalling contributes to inflammation and bone remodelling in axial spondyloarthritis, so blocking the IL-6 receptor is biologically plausible. Ankylosing spondylitis is also closely related to the spondyloarthropathy indication already in the knowledge graph.
However, the two placebo-controlled Phase 3 trials (BUILDER-1 and BUILDER-2 programme) were terminated, and the published literature points to limited efficacy compared with TNF and IL-17 inhibitors. Tocilizumab is therefore best seen as an off-label option only after other biologics have failed.
Clinical Trial Evidence
| Trial Number | Phase | Status | Enrollment | Key Findings |
|---|---|---|---|---|
| NCT01209689 | Phase 3 | Terminated | 113 | Tocilizumab 8 or 4 mg/kg vs placebo in AS patients with inadequate response to TNF antagonists; results not shown in the data |
| NCT01209702 | Phase 2/3 (listed as Phase 3) | Terminated | 306 | Seamless placebo-controlled study in NSAID-failed, TNF-naïve AS; outcome unconfirmed |
| NCT01965132 | N/A | Recruiting | 10000 | Korean biologics registry (RA, AS, PsA); observational safety, not an efficacy trial |
| NCT07138898 | Phase 2 | Recruiting | 80 | Perioperative immunosuppressant management before shoulder arthroplasty; not related to AS efficacy |
Literature Evidence
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 23765873 | 2014 | Randomised placebo-controlled trials (BUILDER-1/2) | Ann Rheum Dis | Assessment of short-term symptomatic efficacy and safety of tocilizumab in AS |
| 26986130 | 2016 | Systematic review / network meta-analysis | Medicine | Comparative effectiveness of biologic regimens for AS |
| 31852268 | 2020 | Systematic review | Expert Rev Clin Immunol | Infection risk with biologics vs non-biologics in inflammatory arthritis |
| 25488787 | 2014 | Review | Best Pract Res Clin Rheumatol | Treatment of spondyloarthritis beyond TNF blockade |
| 28413099 | 2017 | Review | Semin Arthritis Rheum | Second-line biologic choice in RA, PsA and axial SpA |
| 22450391 | 2012 | Review | Curr Opin Rheumatol | Alternatives for AS refractory to TNF inhibition |
| 22452603 | 2012 | Short review | Inflamm Allergy Drug Targets | Antagonising IL-6 in AS |
| 33981717 | 2021 | Case report | Front Med | Two cases of AA amyloidosis in AS treated successfully with tocilizumab |
| 29290076 | 2018 | Meta-analysis | Clin Rheumatol | Serious infection risk with biologics in AS and nr-axSpA |
| 36260501 | 2022 | Systematic literature review | RMD Open | Efficacy and safety of IL-6 pathway inhibition across immune-mediated diseases |
Singapore Market Information
| Authorization Number | Product Name | Dosage Form | Approved Indication |
|---|---|---|---|
| SIN13723P | Actemra Concentrate for Solution for Infusion 20mg/ml | Infusion, solution concentrate | Not stated in the compiled records |
| SIN14837P | Actemra 162mg Solution for Injection in Pre-filled Syringe 162mg/0.9ml | Injection, solution | Not stated in the compiled records |
Safety Considerations
- Drug Interactions: 100 interactions were recorded. Among those listed, the one rated Major is deferiprone. Several Moderate interactions are listed, including statins (rosuvastatin, simvastatin), anticoagulants (warfarin, apixaban, rivaroxaban, dicoumarol), antimalarials (chloroquine, hydroxychloroquine), nitroimidazoles (metronidazole, tinidazole, secnidazole, benznidazole), naltrexone, disulfiram and lidocaine. Zinc salts are rated Minor.
- Infection risk: The literature raises tuberculosis and serious infection risk with IL-6 blockade, so screening is relevant before use.
Please refer to the package insert for warnings and contraindications, as label text was not available in the data compiled for this report.
Conclusion and Next Steps
Decision: Hold
Rationale: The biological rationale for IL-6 blockade in AS is plausible, and the TxGNN score is very high. However, both Phase 3 placebo-controlled AS trials were terminated, published literature suggests limited efficacy relative to TNF and IL-17 inhibitors, and package insert safety data are missing.
To proceed, the following is needed:
- Full results and reasons for termination of NCT01209689 and NCT01209702, plus the BUILDER-1/2 publication data
- Singapore package insert warnings and contraindications (HSA)
- Mechanism of action data from DrugBank
- A defined place in therapy (for example, after failure of TNF and IL-17 inhibitors) with an infection and laboratory monitoring plan
Other Predicted Indications (Brief Notes)
- Polyarticular juvenile idiopathic arthritis (L1, Proceed with Guardrails): Supported by a completed Phase 3 randomised withdrawal trial (NCT00988221, n=188) and several extension studies. This is effectively covered by the existing juvenile idiopathic arthritis indication, so it is a label-concordant rediscovery rather than true repurposing. Monitor infections, neutropenia, transaminases and lipids, and use weight-appropriate dosing.
- Rheumatoid factor-positive polyarticular JIA (L2, Proceed with Guardrails): A subtype within the pJIA programme; evidence is indirect, with subtype-specific data limited to a single-centre case series.
- Inflammatory spondylopathy (L2, Hold): The same disease space and caveats as ankylosing spondylitis.
- Rheumatoid vasculitis (L4, research question): Only case reports exist, and paradoxical vasculitis-like reactions to tocilizumab have been described.
- Mendelian susceptibility to mycobacterial diseases (IL12B deficiency) (L5, Hold): No clinical evidence, and IL-6 blockade raises a safety concern because of mycobacterial infection susceptibility.
- Spondyloarthropathy susceptibility, vertebral disease, hypermobility of coccyx, Kummell disease (L5, Hold): Predictions are computational only, with no supportive clinical evidence.
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.