Defibrotide
| Evidence Level: L5 | Predicted Indications: 10 |
Table of Contents
Defibrotide: From Hepatic Veno-Occlusive Disease to Pseudo-von Willebrand Disease
One-Sentence Summary
Defibrotide is an injectable endothelial-protective, antithrombotic agent marketed in the US as DEFITELIO. The pack lists no approved-indication text, so the original use is taken from the drug’s known label (hepatic veno-occlusive disease after stem cell transplant), not from the pack. The TxGNN model predicts it may be effective for pseudo-von Willebrand disease, but there are 0 clinical trials and 0 publications supporting this direction, and the mechanism points the wrong way.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Not stated in the data (known label use: hepatic veno-occlusive disease after HSCT) |
| Predicted New Indication | Pseudo-von Willebrand disease |
| TxGNN Prediction Score | 99.91% |
| Evidence Level | L5 |
| US Market Status | ✓ Marketed |
| Number of NDAs | 1 |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Detailed mechanism of action data is not currently available in the pack. The available rationale describes defibrotide as a profibrinolytic, antithrombotic, endothelial-protective agent.
Pseudo-von Willebrand disease is a platelet-type bleeding disorder caused by a gain-of-function defect in platelet GPIb-alpha. A drug that reduces clotting and promotes fibrinolysis has no evident therapeutic role here. It could plausibly worsen bleeding.
The high graph score therefore looks like a statistical artefact of the knowledge graph, not a mechanistically grounded prediction. Most other top-ranked predictions (ranks 2, 3, 5-9) are also bleeding or platelet disorders with the same problem.
Clinical Trial Evidence
Currently no related clinical trials registered.
Literature Evidence
Currently no related literature available.
US Market Information
| Authorization Number | Product Name | Dosage Form | Manufacturer |
|---|---|---|---|
| NDA208114 | DEFITELIO | Injection, solution | Jazz Pharmaceuticals, Inc. |
Safety Considerations
- Drug Interactions: The DDI query returned no records, so the data are incomplete, not evidence of no interactions.
- Mechanism-based concern: Defibrotide’s antithrombotic and profibrinolytic activity carries a theoretical bleeding risk, which matters in a bleeding disorder.
Please refer to the package insert for warnings and contraindications.
Conclusion and Next Steps
Decision: Hold
Rationale: The prediction rests on a model score alone (L5). The proposed mechanism is opposite to what a bleeding disorder needs, and no trials or publications support it.
To proceed, the following is needed:
- Package insert warnings and contraindications (a blocking data gap)
- Mechanism of action data from DrugBank
- A plausible mechanistic argument for GPIb-alpha gain-of-function disease, or deprioritisation of this candidate
Note on other predictions: The only direction with literature support in this pack is thrombotic thrombocytopenic purpura (rank 4, L4, “Research Question”). It rests on small, mostly 1990s case reports and transplant-associated thrombotic microangiopathy studies. One 1994 report describes TTP occurring after defibrotide, which is a safety signal. This direction is worth reviewing separately.
This report is for research reference only and does not constitute medical advice. Repurposing candidates require clinical validation before any use.
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.