Tocilizumab

證據等級: L5

預測適應症: 10 個

Tocilizumab: From Rheumatoid Arthritis to Ankylosing Spondylitis

One-Sentence Summary

Tocilizumab is a humanized anti-IL-6 receptor monoclonal antibody whose established use is rheumatoid arthritis (per literature within this evidence pack, e.g. PMID 19368420, 22315615). The TxGNN model predicts a 99.99% score for Ankylosing Spondylitis as a new indication, but the evidence behind this top-ranked prediction is actually negative: two dedicated Phase 3 RCTs (n=113 and n=306) were terminated early for lack of efficacy, so this candidate should not be read as a positive repurposing signal despite its high evidence-level classification.

Quick Overview

Item	Content
Original Indication	Rheumatoid Arthritis (not present in `taiwan_regulatory.licenses`, which is empty; derived from literature evidence in this pack, e.g. PMID 19368420)
Predicted New Indication	Ankylosing Spondylitis
TxGNN Prediction Score	99.99% (rank 245)
Evidence Level	L1 (quantity-based; see caveat below)
New Zealand Market Status	Not Marketed
Number of Authorizations	0
Recommended Decision	Hold

Why is This Prediction Reasonable?

Detailed mechanism-of-action data is not available in this evidence pack (original_moa: Data Gap). Based on literature captured in the evidence itself, tocilizumab is a recombinant humanized monoclonal antibody that blocks the IL-6 receptor (IL-6R), used as a biologic DMARD primarily in rheumatoid arthritis and related IL-6-driven inflammatory conditions.

Ankylosing spondylitis (AS) is superficially similar to RA as a chronic inflammatory rheumatic disease, which is why the TxGNN model scores this pairing so highly. However, the actual pathophysiology of AS is dominated by the IL-17/TNF/IL-23 axis, with IL-6 playing a comparatively minor role — this is a textbook case of a "mechanistically plausible but clinically disproven" prediction.

This is confirmed by the trial evidence itself: two purpose-built Phase 3 RCTs (NCT01209689 and NCT01209702, the BUILDER-1/2 program) tested tocilizumab against placebo in AS and were terminated early, consistent with a lack of demonstrated efficacy. The high TxGNN score and L1 evidence-level label therefore reflect the volume of Phase 3 investigation, not a positive outcome — this distinction is critical for interpreting the recommendation below.

Clinical Trial Evidence

Trial Number	Phase	Status	Enrollment	Key Findings
NCT01209689	Phase 3	Terminated	113	RCT of tocilizumab vs placebo in AS patients with inadequate response to prior TNF antagonist therapy — terminated early (negative/insufficient efficacy signal)
NCT01209702	Phase 2/3	Terminated	306	Seamless Ph II/III RCT of tocilizumab vs placebo in NSAID-failure, TNF-naïve AS patients — terminated early, same negative program as above
NCT05670301	N/A	Recruiting	2500	Observational biomarker/cytokine profiling study across systemic inflammatory diseases (not AS/tocilizumab-specific)
NCT01965132	N/A	Recruiting	10000	Korean nationwide registry of biologics/targeted DMARDs safety in RA, AS, and PsA (real-world safety, not efficacy)
NCT02569736	N/A	Completed	60	Mechanistic study of tocilizumab's effect on T follicular helper cells and B-cell maturation in RA patients (not AS)
NCT07138898	Phase 2	Not yet recruiting	80	Perioperative immunosuppressant management around shoulder arthroplasty in rheumatology patients (not disease-specific to AS)
NCT07477795	Phase 2	Not yet recruiting	52	Trial of secukinumab (not tocilizumab) in Takayasu arteritis — low relevance, likely broad-category match
NCT02925338	N/A	Completed	1431	Real-world observational registry for Inflectra (infliximab), not tocilizumab — low relevance
NCT05696106	N/A	Unknown	750000	Risk of incident immune-mediated inflammatory diseases in patients on biologics/immunosuppressants generally, not tocilizumab/AS-specific

Note: only the top two trials are graded "A" (directly relevant) by the pack's own relevance review; both are negative results. The remaining trials are broader disease-category matches with limited direct bearing on tocilizumab-in-AS efficacy.

Literature Evidence

PMID	Year	Type	Journal	Key Findings
23765873	2014	RCT	Annals of the Rheumatic Diseases	BUILDER-1/BUILDER-2 RCTs assessing short-term symptomatic efficacy and safety of tocilizumab in AS — corresponds to the terminated Phase 3 program above
26986130	2016	Systematic Review / Network Meta-analysis	Medicine	Bayesian network meta-analysis comparing effectiveness of all available biologic regimens for AS
22452603	2012	Review	Inflammation & Allergy Drug Targets	Short review specifically on antagonizing IL-6 in AS
21803631	2011	Review	Joint Bone Spine	Biologic agents for AS beyond TNFα antagonists
22450391	2012	Review	Current Opinion in Rheumatology	Treatment options for AS refractory to TNF inhibition
29278210	2017	Review	Current Pharmaceutical Biotechnology	Biologics in inflammatory and immune-mediated arthritis, including AS
19822066	2009	Review	Clinical and Experimental Rheumatology	Biologics in RA and AS, contrasting pathogenesis and treatment response
27789989	2009	Review	Open Access Rheumatology	Comprehensive review of biologics in RA, AS, and PsA
29290076	2018	Meta-analysis	Clinical Rheumatology	Risk of serious infections with biologics in AS/non-radiographic axSpA
20959960	2011	Review	Osteoporosis International	Systemic bone effects of biologic therapies in RA and AS

New Zealand Market Information

Tocilizumab currently holds no marketing authorization in New Zealand (0 licenses on record; market status: Not Marketed). No product-level dosage form or approved-indication data is available for this market.

Safety Considerations

Please refer to the package insert for safety information.

Conclusion and Next Steps

Decision: Hold

Rationale: Despite an L1 evidence-level classification (driven by two Phase 3 RCTs) and a top TxGNN score, both dedicated Phase 3 trials of tocilizumab in AS were terminated early for lack of efficacy — this is confirmatory negative evidence, not a repurposing opportunity. AS pathology is IL-17/TNF/IL-23-driven, and IL-6 blockade has not shown a viable clinical benefit in this population.

To proceed, the following is needed:

This candidate should not advance further based on current evidence; no additional AS-specific trials are warranted.
TFDA/NZ package insert data (DG001, Blocking) and mechanism-of-action confirmation (DG002, High) are still needed to complete baseline safety profiling for tocilizumab generally, independent of this specific indication.
If pursuing repurposing opportunities from this same evidence pack, consider the higher-confidence candidates instead: polyarticular JIA and RF-positive polyarticular JIA (both L1, "Proceed with Guardrails," backed by a completed 188-patient placebo-controlled Phase 3 RCT), noting these already represent internationally approved indications rather than novel repurposing.
Disclaimer

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