Riociguat
| Evidence Level: L2 | Predicted Indications: 10 |
Table of Contents
- Riociguat
- Riociguat: From Pulmonary Arterial Hypertension to PAH Associated with Connective Tissue Disease
Riociguat: From Pulmonary Arterial Hypertension to PAH Associated with Connective Tissue Disease
One-Sentence Summary
Riociguat is a soluble guanylate cyclase (sGC) stimulator already established for pulmonary arterial hypertension (PAH), as confirmed by the PATENT‑1/2 pivotal trial literature in this evidence pack. TxGNN’s single highest-scoring prediction (Ambras type hypertrichosis, 94.9%) has zero supporting evidence and is flagged in the rationale itself as model noise, so it is not a usable candidate. Among the candidates that do have evidence, the model repeatedly surfaces specific PAH etiological subtypes — most notably PAH associated with connective tissue disease (CTD-PAH) — supported by 12 publications, including a dedicated riociguat-specific PATENT‑1/2 subgroup RCT analysis, but no dedicated clinical trials for this subgroup are currently registered.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Pulmonary Arterial Hypertension (PAH) — inferred from PATENT‑1/2 trial literature in this pack; no formal license/label data available |
| Predicted New Indication | PAH associated with Connective Tissue Disease (CTD-PAH) |
| TxGNN Prediction Score | 91.55% |
| Evidence Level | L2 |
| India Market Status | ✗ Not Marketed |
| Number of Registrations | 0 |
| Recommended Decision | Proceed with Guardrails |
⚠️ Note on ranking: TxGNN’s raw #1–#5, #7, #8 candidates (scores 91.5%–94.9%) — including hair-shaft disorders, Dandy-Walker syndrome, and periodontal malformation — have zero clinical trial or literature support, and the pack’s own rationale explicitly labels them prediction noise. This report focuses on the highest-evidence, mechanistically coherent candidate (CTD-PAH) rather than the raw top score.
Why is This Prediction Reasonable?
Formal MOA documentation (DrugBank) is currently a data gap (DG002). However, the literature within this pack consistently characterizes riociguat as a soluble guanylate cyclase (sGC) stimulator that amplifies the NO–sGC–cGMP signaling pathway, producing pulmonary vasodilation as well as anti-proliferative and anti-fibrotic effects on remodeled pulmonary vasculature.
CTD-PAH is not a separate disease but a recognized etiological subgroup within WHO Group 1 PAH — the same broad category riociguat is already indicated for. Connective tissue disease, particularly systemic sclerosis, is one of the largest non-idiopathic contributors to the global PAH population, and the pivotal PATENT‑1/PATENT‑2 phase III program that established riociguat’s efficacy in PAH included a prospectively planned CTD-PAH subgroup (PMID 27457511).
Mechanistically, CTD-PAH shares the same core vasculopathy as idiopathic PAH — medial hypertrophy, intimal fibrosis, and endothelial NO/cGMP deficiency — so riociguat’s sGC-stimulating action is expected to translate similarly. A clinical case series (PMID 28671485) further reports benefit when CTD-PAH patients were switched from PDE5 inhibitors to riociguat, reinforcing the biological plausibility beyond the trial subgroup data alone.
Clinical Trial Evidence
Currently no related clinical trials registered.
(A related trial exists for a different PAH-CHD subgroup — NCT07356778 — but it evaluates sotatercept add-on therapy, not riociguat, so it is not included here.)
Literature Evidence
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 27457511 | 2017 | RCT subgroup analysis | Annals of the Rheumatic Diseases | Riociguat improved outcomes in the PAH-CTD subgroup of the PATENT‑1/PATENT‑2 phase III program |
| 38378970 | 2024 | Systematic review/meta-analysis | Internal and Emergency Medicine | Meta-analysis of RCT subgroup/post-hoc data on CTD-PAH treatment outcomes |
| 37765060 | 2023 | Review | Pharmaceuticals (Basel) | Overview of PAH-CTD pathophysiology and treatment advances, including riociguat |
| 28671485 | 2017 | Cohort (case series) | Pulmonary Circulation | Switching from PDE5 inhibitor to riociguat improved outcomes in 3 PAH-CTD patients |
| 33131480 | 2020 | Review/commentary | Kardiologiia | Discusses riociguat’s role in PAH associated with systemic connective tissue disease |
| 27941129 | 2017 | Guideline (EULAR) | Annals of the Rheumatic Diseases | EULAR recommendations include PAH-targeted therapy for systemic sclerosis |
| 40331647 | 2025 | Cohort (prospective) | Kardiologiia | Long-term survival analysis in PAH associated with autoimmune rheumatic disease |
| 35412560 | 2022 | Review | JAMA | General PAH diagnosis and treatment overview |
| 31090367 | 2019 | Cohort (registry) | Terapevticheskii Arkhiv | Six-year national PAH registry observation |
| 40592721 | 2025 | Review (narrative) | RMD Open | 2025 update on the systemic sclerosis treatment landscape |
India Market Information
Riociguat currently has no registrations and is not marketed in this jurisdiction (0 licenses on file), so no product/dosage-form table is available.
Safety Considerations
- Drug Interactions: 75 documented interactions identified (all Moderate severity in the available data), notably with:
- Proton pump inhibitors (rabeprazole, omeprazole, pantoprazole, lansoprazole, dexlansoprazole, esomeprazole)
- SGLT2 inhibitors (canagliflozin, dapagliflozin, empagliflozin, ertugliflozin)
- Antacids/mineral agents (magnesium oxide/carbonate/hydroxide, calcium carbonate, aluminum hydroxide, magaldrate, mannitol)
- Dexamethasone, clarithromycin, papaverine
Formal label warnings and contraindications are a blocking data gap (DG001) and are not yet available in this pack.
Conclusion and Next Steps
Decision: Proceed with Guardrails
Rationale: CTD-PAH is a pre-specified subgroup of riociguat’s pivotal PATENT‑1/2 phase III program (tier‑1 RCT subgroup evidence), reinforced by cohort/case-series data — sufficient to advance under guardrails, but not to a full “Go” given the absence of a dedicated trial in this specific subgroup and outstanding blocking safety data gaps.
To proceed, the following is needed:
- Official label warnings/contraindications (DG001 — blocking; required for S1 safety screen)
- Formal DrugBank/regulatory MOA documentation (DG002)
- Market entry/registration assessment, since the drug currently has zero registrations in this jurisdiction
- A dedicated prospective trial or registry analysis in the CTD-PAH population if a formal label extension is sought
- Review of the TxGNN ranking pipeline: six of the ten returned candidates (including the #1-ranked prediction) have no supporting evidence and should be filtered as noise before future evidence packs are generated
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.