Ritonavir
| Evidence Level: L4 | Predicted Indications: 10 |
Table of Contents
Using no special skill here — this is a direct content-generation task per the given report template, not a coding/debugging task.
Ritonavir: From HIV-1 Infection to Simian Immunodeficiency Virus Infection
One-Sentence Summary
Ritonavir is an HIV-1 protease inhibitor originally used to treat HIV-1 infection, most commonly today as a pharmacokinetic booster for other protease inhibitors. The TxGNN model’s top-ranked prediction associates it with Simian Immunodeficiency Virus (SIV) Infection — an animal disease model, not a human condition — supported only by 0 clinical trials and 12 preclinical publications, indicating this is likely an ontology mismatch rather than a genuine human repurposing opportunity.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | HIV-1 Infection (established per evidence-pack rationale text; no formal EU/Taiwan license record retrieved) |
| Predicted New Indication | Simian Immunodeficiency Virus Infection |
| TxGNN Prediction Score | 99.92% |
| Evidence Level | L4 |
| EU Market Status | ✗ Not Marketed |
| Number of Authorizations | 0 |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Currently, detailed mechanism of action data for ritonavir is not available in this evidence pack (flagged as a High-severity data gap). Based on known information referenced throughout the evidence pack’s own repurposing rationales, ritonavir is an HIV-1 protease inhibitor, and its efficacy in HIV-1 infection is well established both as a direct antiviral and as a CYP3A4-mediated booster for co-administered protease inhibitors.
SIV is the simian (macaque) analog of HIV used almost exclusively as a nonhuman primate research model for HIV/AIDS pathogenesis and antiretroviral drug testing — it is not a naturally occurring human disease. The mechanistic link exists at the structural level: SIV protease shares homology with HIV-1 protease, and in vitro data (PMID 12709355) show ritonavir inhibits SIVmac239 with an EC50 of ~13 nM, comparable to its activity against HIV-1 (~25 nM).
However, this mechanistic plausibility does not translate into a viable human repurposing candidate — SIV does not infect humans, and the “indication” itself is a laboratory/animal-model construct. The high TxGNN score most likely reflects the model treating SIV and HIV as closely related graph neighbors (shared drug-target and pathway edges) rather than identifying a novel, clinically actionable indication.
Clinical Trial Evidence
Currently no related clinical trials registered.
Literature Evidence
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 12709355 | 2003 | In vitro/Preclinical | Antimicrob Agents Chemother | Ritonavir inhibits SIVmac239 in vitro (EC50 ≈13 nM), comparable potency to HIV-1 inhibition |
| 15040537 | 2004 | In vitro/Preclinical | Antiviral Therapy | Comparative susceptibility of HIV-2, SIV, and SHIV strains to 16 approved anti-HIV-1 drugs including ritonavir |
| 16973590 | 2006 | Animal model study | Journal of Virology | Viral decay kinetics in SIV-infected macaques receiving quadruple antiretroviral therapy |
| 25033210 | 2014 | Animal model study | PLoS ONE | Combination cART plus HDAC inhibitor SAHA in SIV-infected rhesus macaques (viral reservoir study) |
| 22737073 | 2012 | Animal model study | PLoS Pathogens | Intensified multidrug ART regimen suppresses viremia and restricts viral reservoir in SIV-infected macaques |
| 17350308 | 2007 | In vitro/Animal model | Microbes and Infection | Construction of chimeric SHIV bearing HIV-1 protease gene, for in vivo protease-inhibitor efficacy testing |
| 12951220 | 2003 | Animal model study | Journal of Virological Methods | Oral HAART (including lopinavir/ritonavir) impact on CD8 subsets in SHIV-infected monkeys |
| 12186895 | 2002 | In vitro mechanistic | Journal of Virology | HIV-1 Vif protein processing by viral protease; mechanistic study, not ritonavir-specific efficacy |
| 34903055 | 2021 | Preclinical/mechanistic | mBio | Lentiviral (HIV) persistence in brain tissue despite effective ART; relevance to SIV models discussed |
| 9875393 | 1998 | In vitro/Preclinical | Antiviral Chemistry & Chemotherapy | Broad-spectrum antiviral fluoroquinolone derivative active against HIV-1, HIV-2, and SIV, including ritonavir-resistant HIV-1 strains |
EU Market Information
No marketing authorization records are available in this evidence pack (total_licenses = 0, market_status = Not Marketed). This is inconsistent with ritonavir’s known long-standing EU approval (e.g., Norvir) and likely reflects a data collection gap in this specific evidence pull rather than an actual absence of EU authorization.
Safety Considerations
Please refer to the SmPC for safety information.
Conclusion and Next Steps
Decision: Hold
Rationale: The top-ranked predicted indication, Simian Immunodeficiency Virus Infection, is an animal research model rather than a human disease, and is supported only by L4 (preclinical/mechanistic) evidence with zero registered clinical trials. It cannot be advanced as a human repurposing candidate.
To proceed, the following is needed:
- Resolve the TFDA/EMA label warnings and contraindications data gap (DG001, Blocking) — required before any S1 safety review, per source: TFDA label PDF parsing
- Resolve the mechanism-of-action data gap (DG002, High) via DrugBank API query
- Correct or re-verify the EU marketing-authorization data pull for ritonavir, given the known discrepancy with its established EMA approval
- Review whether the SIV/HIV disease nodes in the underlying knowledge graph should be merged or flagged, since this appears to be an ontology-mapping artifact rather than a novel signal
- If a genuine repurposing signal is sought from this drug’s prediction set, evaluate the lower-ranked but more clinically translatable candidates already present in this pack (e.g., hepatitis E virus infection at L4/S1 with a distinct viral-entry-inhibition mechanism, or ritonavir-boosted PI use in perinatal/pediatric HIV at L1/S3) as separate, better-supported candidates
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.