Abacavir Core
| 證據等級: L5 | 預測適應症: 0 個 |
目錄
Abacavir: HIV Antiretroviral — No Repurposing Predictions Available
One-Sentence Summary
Abacavir is a nucleoside reverse transcriptase inhibitor (NRTI) used as part of combination antiretroviral therapy for HIV-1 infection. The TxGNN model returned no predicted new indications for this drug entry, and the drug currently has no registered products in Singapore, making a full repurposing evaluation impossible at this stage. The primary cause is a missing DrugBank ID and an unresolved drug identity flag ("CORE"), which prevented the prediction engine from completing a knowledge graph lookup.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | HIV-1 infection (combination antiretroviral therapy) |
| Predicted New Indication | None — no TxGNN predictions returned |
| TxGNN Prediction Score | N/A |
| Evidence Level | N/A — no predictions available |
| Singapore Market Status | Not marketed |
| Number of Registrations | 0 |
| Recommended Decision | Hold |
Why Evaluation Cannot Proceed
The TxGNN pipeline returned an empty predicted_indications list for this entry. Based on the query log and metadata, three compounding issues likely caused the failure:
1. Unresolved drug identity ("CORE" label) The drug is recorded as "ABACAVIR (CORE)", suggesting it was extracted as a core active ingredient from a fixed-dose combination product (e.g., Epzicom or Triumeq) rather than mapped as a standalone monotherapy entity. This label mismatch may have caused the normalisation step to fail drug node lookup in the knowledge graph.
2. Missing DrugBank ID
Without a confirmed DrugBank ID, the knowledge graph cannot locate the drug node, and no disease–drug edges can be scored by TxGNN. The DrugBank query returned a result (result_count: 1), but the ID was not propagated into the evidence pack — this is a pipeline data-linkage issue that needs to be resolved upstream.
3. Missing mechanism of action data With no MOA available, the model loses a key feature for inferring mechanistic similarity to candidate diseases, further reducing prediction confidence to below the output threshold.
From background knowledge, Abacavir's mechanism — intracellular phosphorylation to carbovir triphosphate, which competitively inhibits HIV-1 reverse transcriptase and acts as a chain terminator — has been explored in repurposing literature for other RNA viruses. However, no model-generated scores or evidence links are present in this evidence pack to support a structured evaluation of any new indication.
Safety Considerations
Please refer to the package insert for safety information.
Important note not captured in this evidence pack: Abacavir carries a well-known black-box warning for potentially fatal hypersensitivity reactions (HSR) associated with the HLA-B*5701 allele. Pre-treatment genetic screening is mandatory in routine clinical practice. This information must be retrieved from the HSA-approved package insert before any further evaluation or clinical consideration proceeds.
Conclusion and Next Steps
Decision: Hold
Rationale: The TxGNN model returned zero predictions for this entry due to a broken drug identity chain — the "(CORE)" label and missing DrugBank ID prevented any disease–drug scoring from completing. There is no prediction output to evaluate, and the drug is not registered in Singapore.
To proceed, the following is needed:
- Resolve drug identity: Confirm whether "ABACAVIR (CORE)" refers to the monotherapy (Ziagen) or a fixed-dose combination component, and align the entry name accordingly
- Link DrugBank ID: The DrugBank query returned one result — retrieve and populate the confirmed ID (expected: DB01048) so the prediction pipeline can complete the knowledge graph lookup
- Re-run TxGNN prediction: After correcting the drug entry, re-run the full prediction pipeline to generate
predicted_indications - Retrieve Singapore/HSA package insert: Populate safety warnings, contraindications, and MOA data from the HSA-registered product label
- Confirm HLA-B*5701 screening requirement: Any repurposing evaluation must account for this mandatory safety screen as a key guardrail for any future indication
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.