Emtricitabine
| Evidence Level: L5 | Predicted Indications: 3 |
Table of Contents
Emtricitabine: From HIV-1 Infection to Simian Immunodeficiency Virus Infection
One-Sentence Summary
Emtricitabine is a nucleoside reverse transcriptase inhibitor (NRTI) used as an antiretroviral for HIV-1 infection. The TxGNN model predicts it may be effective for simian immunodeficiency virus (SIV) infection, an animal-model disease rather than a new human indication. Support is 2 clinical trials (both human HIV studies with only indirect relevance) and 20 publications, mostly preclinical macaque studies.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | HIV-1 infection (general drug knowledge; the SAHPRA indication text in the record is empty) |
| Predicted New Indication | Simian immunodeficiency virus infection |
| TxGNN Prediction Score | 99.92% |
| Evidence Level | L4 (preclinical evidence only) |
| South Africa Market Status | Marketed |
| Number of SAHPRA Registrations | 20 |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Currently, detailed mechanism of action data is not available in the record. Emtricitabine is an NRTI, a class that terminates viral DNA chain elongation. SIV and the chimeric SHIV viruses use a reverse transcriptase closely related to that of HIV-1, so activity is mechanistically plausible. This reasoning rests on general NRTI pharmacology, not on the supplied record.
The literature supports this in macaque models. Emtricitabine combined with tenofovir (TDF or TAF) has been tested for pre-exposure prophylaxis against SHIV, and in one study for SHIV remission. These are non-human primate studies, not human trials.
The prediction largely restates emtricitabine’s existing antiretroviral activity. It does not open a new clinical use for patients in South Africa.
Clinical Trial Evidence
Both registered trials are human HIV studies, not SIV studies. They are indirect evidence at best.
| Trial Number | Phase | Status | Enrollment | Key Findings |
|---|---|---|---|---|
| NCT00863668 | N/A | Withdrawn | 0 | HIV decay kinetics with raltegravir. Withdrawn with no participants, so no data. Emtricitabine is not evident from the title. |
| NCT03577782 | Phase 1/2 | Unknown | 12 | Vedolizumab plus antiretroviral therapy for virological remission in HIV-infected people. Emtricitabine is at most part of the ART background. |
No SANCTR or PACTR identifiers are available in the record.
Literature Evidence
All entries below are preclinical or non-human primate work, except one review. No RCTs were supplied. Findings are taken from titles and truncated abstracts only.
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 31362305 | 2019 | Preclinical (NHP) | J Infect Dis | Oral TAF/emtricitabine or TAF alone tested against vaginal SHIV infection in macaques. |
| 29788316 | 2018 | Preclinical (NHP) | J Infect Dis | Vaginal emtricitabine/tenofovir gel tested against repeated rectal SHIV exposures. |
| 27465645 | 2016 | Preclinical (NHP) | J Infect Dis | Oral emtricitabine plus TAF protected macaques from rectal SHIV infection. |
| 26743846 | 2016 | Preclinical (NHP) | J Infect Dis | Emtricitabine/TDF prevented vaginal SHIV infection in macaques coinfected with Chlamydia and Trichomonas. |
| 39632836 | 2024 | Preclinical (NHP) | Nat Commun | Early oral emtricitabine/TAF plus long-acting cabotegravir/rilpivirine gave SHIV remission in macaques. |
| 23633402 | 2013 | Preclinical (NHP) | J Infect Dis | Emtricitabine/TDF prophylaxis tested against tenofovir-resistant (K65R) SHIV in macaques. |
| 22814162 | 2012 | Preclinical (NHP) | Jpn J Infect Dis | Double oral emtricitabine/tenofovir dosing before exposure protected against highly pathogenic SHIV in macaques. |
| 21632769 | 2011 | Preclinical (NHP) | J Virol | Intermittent Truvada protected against an emtricitabine-resistant (M184V) SHIV mutant. |
| 20874040 | 2010 | Review | Pharmacotherapy | Review of systemic pre-exposure prophylaxis for HIV infection. |
| 12021341 | 2002 | Preclinical virology | J Virol | SIV with the M184V mutation emerged in macaques treated with lamivudine or emtricitabine, with reduced viral fitness. |
South Africa Market Information
Twenty SAHPRA registrations are recorded. The first five are shown below. The approved indication text is empty in the record, so it is not listed.
| Registration Number | Product Name | Dosage Form |
|---|---|---|
| Reg. No. 47/20.2.8/0188 | Emtroc 200mg/300mg | Tablet |
| Reg. No. 41/20.2.8/0171 | Truvada | Tablet |
| Reg. No. 41/2.6.5/1056 | Rutra 1 Mg/Ml Solution | Solution |
| Reg. No. A40/20.2.8/0508 | Sonke-efavirenz | Tablet |
| Reg. No. 55/20.2.8/0080.079 | Tafbin | Film-coated tablet (recorded as “Fct”) |
Essential Medicines List (EML) status is not available in the record.
Safety Considerations
Please refer to the SAHPRA-approved Professional Information (PI) for safety information. Report adverse drug reactions to SAHPRA.
Conclusion and Next Steps
Decision: Hold
Rationale: The predicted indication is an animal-model infection, not a human disease, and the supporting evidence is preclinical (L4). The prediction mostly restates emtricitabine’s existing HIV-1 antiretroviral activity, so it offers no new use for South African patients.
The other two predictions do not change this. Feline acquired immunodeficiency syndrome is also veterinary, with L4 evidence and only indirect human HIV trials. The neurodevelopmental disorder prediction has no supporting evidence (L5) and no plausible mechanism.
To proceed, the following is needed:
- SAHPRA package insert warnings and contraindications, so that safety screening can begin
- Mechanism of action data from DrugBank
- Confirmation of the approved indication text for the SAHPRA registrations
- A clear decision on whether a veterinary or research-model use is in scope at all; if not, the candidate should be closed
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.