Lamivudine
| Evidence Level: L5 | Predicted Indications: 5 |
Table of Contents
- Lamivudine
- Lamivudine: From HIV-1/Hepatitis B Infection to Feline Acquired Immunodeficiency Syndrome
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Lamivudine: From HIV-1/Hepatitis B Infection to Feline Acquired Immunodeficiency Syndrome
One-Sentence Summary
Lamivudine (3TC) is a nucleoside reverse transcriptase inhibitor (NRTI) publicly known for treating HIV-1 infection and chronic hepatitis B, though this evidence pack itself contains no confirmed original indication or UK licence data. The TxGNN model’s top-ranked prediction is Feline Acquired Immunodeficiency Syndrome (FIV) — a veterinary, not human, condition — supported by 0 clinical trials and 5 preclinical/veterinary publications, with no data suggesting clinical relevance to human medicine.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Not on file in this evidence pack (no UK licences recorded); lamivudine is widely known as an antiretroviral for HIV-1 infection and chronic hepatitis B |
| Predicted New Indication | Feline Acquired Immunodeficiency Syndrome (FIV) — a veterinary condition, not a human disease |
| TxGNN Prediction Score | 99.93% |
| Evidence Level | L4 (preclinical/mechanistic studies only; no clinical trials) |
| 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 available in this evidence pack for lamivudine (flagged as a High-severity data gap, DG002). Based on the accompanying literature evidence, lamivudine is known to be a nucleoside reverse transcriptase inhibitor (NRTI), and it is this mechanism — inhibition of retroviral reverse transcriptase — that underpins the TxGNN association with FIV: feline immunodeficiency virus is a lentivirus closely related to HIV, and the literature confirms lamivudine (often combined with zidovudine) has been studied in vitro and in cats as an anti-FIV agent, mirroring its established use against HIV in humans.
However, this mechanistic plausibility does not translate into clinical relevance for a UK healthcare setting: FIV is a disease of domestic cats, not humans, so this candidate has no direct human therapeutic application. The evidence pack’s own scoring also flags the model’s next-ranked predictions as similarly problematic — simian immunodeficiency virus infection (rank 2, also non-human), a rare neurodevelopmental disorder (rank 3, “no identifiable mechanistic link… likely a false positive”), and familial combined hyperlipidaemia (rank 4, “contradicts known pharmacology,” since NRTIs are more commonly associated with causing dyslipidaemia than treating it). Chronic hepatitis C infection (rank 5) is mechanistically weak as well, since HCV is a positive-strand RNA virus that does not use reverse transcription, and most of the associated “clinical trials” are mislabelled hepatitis B studies.
Taken together, none of TxGNN’s top five predictions for lamivudine currently represent a clinically actionable human repurposing candidate on the evidence available.
Clinical Trial Evidence
Currently no related clinical trials registered.
Literature Evidence
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 25855689 | 2016 | Case series (feline, long-term follow-up) | J Feline Med Surg | Long-term antiretroviral therapy (zidovudine-based, with lamivudine literature context) evaluated in FIV-infected domestic cats over 5–6 years |
| 22816032 | 2012 | Animal study | Viruses | Compared antiretroviral protocols, including zidovudine + lamivudine, in naturally FIV-infected cats in the late asymptomatic stage |
| 11943320 | 2002 | In vitro/in vivo study | Vet Immunol Immunopathol | AZT/3TC combination showed additive-to-synergistic anti-FIV activity in primary PBMCs but not chronically infected cells |
| 11684314 | 2002 | In vitro study | Antiviral Res | Zidovudine + lamivudine + abacavir combination suppressed FIV replication in vitro; FIV proposed as an animal model for HIV |
| 11327469 | 2001 | In vitro characterisation study | Am J Vet Res | Characterised a pathogenic FIV molecular clone and two lamivudine (3TC)-resistant reverse transcriptase mutants |
UK Market Information
No UK marketing authorisation records are held for lamivudine in this evidence pack (market status: Not Marketed; 0 licences on file). This is flagged as a Blocking data gap (DG001) pending retrieval of the relevant SmPC/product licence data.
Safety Considerations
Please refer to the SmPC and BNF for safety information. Report suspected adverse reactions via the Yellow Card Scheme.
Conclusion and Next Steps
Decision: Hold
Rationale: The top-ranked TxGNN prediction (feline AIDS) is a veterinary condition with no direct application to human patients, and the supporting evidence is limited to five preclinical/veterinary publications with no clinical trials. No UK marketing authorisation, mechanism-of-action confirmation, or safety data (warnings, contraindications, DDI) are available to support progression, and the remaining ranked predictions (SIV infection, a rare neurodevelopmental disorder, familial hyperlipidaemia, chronic HCV) are each independently assessed as mechanistically weak, contradicted by known pharmacology, or non-human in scope.
To proceed, the following is needed:
- Confirmation of a clinically meaningful human indication among lamivudine’s already-established uses (e.g. HIV-1, chronic hepatitis B) before further repurposing evaluation
- Resolution of Blocking data gap DG001: MHRA/SmPC warnings and contraindications
- Resolution of High-severity data gap DG002: verified mechanism of action from DrugBank
- Re-screening of the TxGNN candidate list for a genuinely human, mechanistically plausible indication, since none of the current top five meet that bar
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.