Tocilizumab
| Evidence Level: L3 | 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 arteritis and Castleman disease. The TxGNN model predicts it may be effective for Ankylosing Spondylitis, but the two main Phase 3 trials (2 trials) were terminated, and the 19 publications are mostly reviews, with only one trial-result report (BUILDER-1/2) and one case report. The strongest-supported prediction among the top 10 is actually polyarticular juvenile idiopathic arthritis, which overlaps with an existing indication.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Rheumatoid arthritis, juvenile idiopathic arthritis, giant cell arteritis, Castleman disease and others (the US license indication text is not available in the data compiled for this report) |
| Predicted New Indication | Ankylosing spondylitis |
| TxGNN Prediction Score | 99.99% |
| Evidence Level | L3 |
| US Market Status | Cancelled only (6 licenses, all cancelled) |
| Number of NDAs | 6 (all BLAs) |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Detailed mechanism-of-action data is not available in the data compiled for this report. Based on known information, tocilizumab is a humanized monoclonal antibody that blocks the interleukin-6 (IL-6) receptor. Its efficacy in rheumatoid arthritis and juvenile idiopathic arthritis is established.
IL-6 contributes to systemic inflammation and bone effects in spondyloarthritis, so blocking its receptor is biologically plausible. Ankylosing spondylitis also shares inflammatory pathways with the rheumatic diseases the drug already treats.
The clinical record is less supportive. Two randomized placebo-controlled trials in AS were terminated, and the published literature indicates that IL-6 blockade did not show benefit comparable to TNF or IL-17 inhibition. The prediction is therefore mechanistically plausible but not clinically confirmed.
Clinical Trial Evidence
| Trial Number | Phase | Status | Enrollment | Key Findings |
|---|---|---|---|---|
| NCT01209689 | Phase 3 | Terminated | 113 | Placebo-controlled; tocilizumab 8 or 4 mg/kg IV vs placebo in AS with inadequate response to TNF antagonists. Terminated, so no efficacy conclusion can be drawn |
| NCT01209702 | Phase 2/3 | Terminated | 306 | Seamless placebo-controlled study in TNF-naïve AS patients who failed NSAIDs. Early termination weakens the evidence |
| NCT01965132 | N/A | Recruiting | 10,000 | Korean registry of biologics safety in RA, AS and PsA; no tocilizumab-specific AS efficacy data |
| NCT07138898 | Phase 2 | Recruiting | 80 | Perioperative immunosuppressant management in rheumatology patients undergoing shoulder arthroplasty; not an efficacy trial |
Literature Evidence
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 23765873 | 2014 | RCT report (BUILDER-1/2) | Ann Rheum Dis | Short-term symptomatic efficacy and safety of tocilizumab in AS from the two randomized placebo-controlled trials |
| 26986130 | 2016 | Systematic review / network meta-analysis | Medicine | Comparative effectiveness of biologic regimens for AS |
| 36260501 | 2022 | Systematic review | RMD Open | Literature review informing consensus on IL-6 pathway inhibition in immune-mediated inflammatory diseases |
| 31852268 | 2020 | Systematic review / meta-analysis | Expert Rev Clin Immunol | Infection risk with biologics vs non-biologics in inflammatory arthritis |
| 22452603 | 2012 | Review | Inflamm Allergy Drug Targets | Short review of antagonizing IL-6 in AS |
| 22450391 | 2012 | Review | Curr Opin Rheumatol | Alternatives for AS patients refractory to TNF inhibition |
| 25488787 | 2014 | Review | Best Pract Res Clin Rheumatol | Treatment of spondyloarthritis beyond TNF-alpha blockade |
| 33981717 | 2021 | Case report | Front Med | Two cases of AA amyloidosis in AS successfully treated with tocilizumab |
| 29290076 | 2018 | Meta-analysis | Clin Rheumatol | Serious infection risk with biologics in AS and nr-axSpA |
| 39963138 | 2025 | Review/Guideline | Front Immunol | Tuberculosis risk, screening and preventive therapy in patients on biologics |
US Market Information
| Authorization Number | Product Name | Dosage Form | Approved Indication |
|---|---|---|---|
| BLA761420 | AVTOZMA (Celltrion USA) | Injection, solution | Not available (status: cancelled) |
| BLA761354 | TOFIDENCE (Organon) | Injection | Not available (status: cancelled) |
| BLA125472 | Actemra (Genentech) | Injection, solution | Not available (status: cancelled) |
| BLA761449 | TYENNE (Fresenius Kabi) | Injection, solution | Not available (status: cancelled) |
| BLA125276 | ACTEMRA (Genentech) | Injection, solution, concentrate | Not available (status: cancelled) |
A sixth license, BLA761275 (TYENNE, injection solution concentrate, Fresenius Kabi), is also listed as cancelled. All six licenses carry a cancelled status in the data compiled for this report, which conflicts with the fact that these products are widely marketed. This should be verified against current FDA records.
Safety Considerations
- Drug Interactions: 100 interactions were identified, of which the main ones listed are below.
- Major: Deferiprone
- Moderate: Warfarin, apixaban, rivaroxaban, dicoumarol (anticoagulants); simvastatin, rosuvastatin; chloroquine, hydroxychloroquine; metronidazole, tinidazole, secnidazole, benznidazole; disulfiram; naltrexone; lidocaine
- Minor: Zinc salts (sulfate, acetate, gluconate, chloride)
For warnings and contraindications, please refer to the package insert; this information was not available in the data compiled for this report.
Safety points noted in the literature for IL-6 blockade include infection risk (including tuberculosis, so screening is advised), liver injury, neutropenia and lipid changes. Case reports describe tocilizumab-associated vasculitis-like reactions.
Conclusion and Next Steps
Decision: Hold
Rationale: The IL-6 rationale for ankylosing spondylitis is plausible, but both dedicated Phase 3 trials were terminated and there is no confirmed efficacy; the evidence is limited to reviews and case reports (L3). Among the other top-10 predictions, only the JIA entries have strong support, and polyarticular JIA (Phase 3 randomized withdrawal trial NCT00988221, L1, Proceed with Guardrails) is an established use rather than true repurposing. Rheumatoid vasculitis has only case reports (L4, research question). The remaining predictions (coccyx hypermobility, Kummell disease, IL12B-deficiency mycobacterial susceptibility and others) are model predictions only or are safety concerns, and are likely false positives.
To proceed, the following is needed:
- Review of the BUILDER-1/2 results and the reasons for termination to determine whether it reflected lack of efficacy or feasibility
- FDA package insert warnings and contraindications (a blocking gap for safety screening)
- Mechanism of action data (MOA)
- Verification of the US license status, since all six BLAs show as cancelled
- If pursuing a different direction, a dedicated plan for polyarticular JIA (guardrails: monitor infections, neutrophil counts, liver enzymes and lipids; screen for tuberculosis) or a prospective study in rheumatoid vasculitis
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.