Acetarsol
| 證據等級: L5 | 預測適應症: 10 個 |
目錄
Acetarsol: From Historical Antiprotozoal Use to Diffuse Cutaneous Leishmaniasis
One-Sentence Summary
Acetarsol is a pentavalent organic arsenic compound historically employed as an antiprotozoal and antisyphilitic agent, though no current formal licensed indication is on record in the United Kingdom. The TxGNN model predicts it may have activity against Leishmaniasis, Diffuse Cutaneous, with a prediction confidence of 98.67%. However, no clinical trials and no supporting publications have been identified for this indication, placing this prediction at evidence level L5 — model prediction only, with no empirical study data available.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | No MHRA-authorised indication on record |
| Predicted New Indication | Leishmaniasis, Diffuse Cutaneous |
| TxGNN Prediction Score | 98.67% |
| Evidence Level | L5 |
| UK Market Status | Not marketed |
| Number of Marketing Authorisations | 0 |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Detailed mechanism of action data is not currently available for Acetarsol in this evidence pack. Based on its chemical class, Acetarsol (acetarsone) is a pentavalent organic arsenic compound. Trivalent arsenic species — the biologically active form — are known to inhibit trypanothione reductase, a critical enzyme in the antioxidant defence system unique to kinetoplastid parasites such as Leishmania spp. Disruption of this enzyme overwhelms the parasite’s ability to manage oxidative stress, leading to cell death. This is the primary mechanistic rationale that likely underpins the TxGNN knowledge graph prediction.
An indirect analogical basis also exists: pentavalent antimonials (e.g., sodium stibogluconate, meglumine antimoniate), the current standard of care for leishmaniasis, are structurally and chemically related to pentavalent arsenic compounds. The shared valence state and similar chemical geometry suggest a plausible, if unproven, pharmacological parallel. Historically, arsenic-based compounds were among the earliest antiprotozoal agents used in medicine (e.g., arsphenamine for syphilis), supporting the broader concept of arsenic-class antiparasitic activity.
However, this mechanistic link is explicitly speculative and inferential. Acetarsol is a pentavalent organic arsenic compound, and whether it undergoes sufficient metabolic reduction to active trivalent arsenic in relevant tissue compartments — a prerequisite for trypanothione reductase inhibition — remains entirely uncharacterised. No preclinical, translational, or clinical data have been identified to validate this pathway for Acetarsol specifically. The TxGNN prediction should therefore be regarded as a hypothesis-generating signal only.
Clinical Trials
Currently no related clinical trials registered.
Literature Evidence
Currently no related literature available.
UK Market Information
Acetarsol currently holds no MHRA marketing authorisations and is not marketed in the United Kingdom. It is not listed in the British National Formulary (BNF) and has no approved indications under either national or centralised authorisation procedures. Any clinical development or compassionate use in the UK would require engagement with the MHRA from the outset, including a pre-submission meeting to discuss the regulatory pathway for an unlicensed organoarsenic compound.
Safety Considerations
No specific safety data — including key warnings, contraindications, or drug–drug interactions — are available within this evidence pack.
Please refer to the SmPC and BNF for safety information. Report suspected adverse reactions via the Yellow Card Scheme.
As a member of the organoarsenic compound class, Acetarsol carries inherent toxicological concerns applicable to the arsenic chemical class as a whole. These include potential nephrotoxicity (arsenic-induced tubular injury and oxidative damage), hepatotoxicity, peripheral neuropathy, haematological toxicity (including bone marrow suppression), and QTc prolongation — the last of which is well-characterised for inorganic arsenic trioxide (As₂O₃). Whether the same toxicity profile applies to Acetarsol at therapeutic doses has not been formally evaluated in contemporary settings. This uncertainty constitutes a significant safety data gap that would be blocking for any clinical development programme.
Conclusion and Next Steps
Decision: Hold
Rationale: This prediction rests entirely on TxGNN knowledge graph inference (L5 evidence), with no supporting preclinical or clinical data, and Acetarsol holds no marketing authorisation in the United Kingdom. The mechanistic link to diffuse cutaneous leishmaniasis is biologically plausible in principle but remains wholly unvalidated, and the arsenic-class toxicity profile introduces substantial safety uncertainties that cannot be resolved from currently available information.
To proceed, the following is needed:
- Mechanism of action characterisation: Determine whether Acetarsol undergoes in vivo reduction to trivalent arsenic species at pharmacologically relevant concentrations, and whether this occurs in Leishmania-infected tissues
- Preclinical efficacy data: In vitro activity against Leishmania spp. (axenic amastigotes and intracellular macrophage models); in vivo murine leishmaniasis models
- Comprehensive safety and toxicology profiling: Including arsenic-specific endpoints (nephrotoxicity, hepatotoxicity, peripheral neuropathy, QTc, haematological parameters) via contemporary GLP studies
- MHRA regulatory pathway assessment: Pre-submission engagement required given unlicensed status; arsenic compounds may face heightened scrutiny
- Clinical unmet need analysis: Benchmarking against existing treatments (pentavalent antimonials, liposomal amphotericin B, miltefosine, paromomycin) to identify patient populations where Acetarsol could offer a meaningful advantage
- Full SmPC and available historical safety documentation review: To recover any pre-existing toxicity data from historical clinical use records
This report is generated for research purposes only and does not constitute medical advice. All drug repurposing candidates require rigorous clinical validation before any therapeutic application. Data cut-off: 4 April 2026.
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.