Glycine
| Evidence Level: L5 | Predicted Indications: 2 |
Table of Contents
Glycine: From Maple Syrup Urine Disease (Acute Decompensation) to Nasal Cavity Disease
One-Sentence Summary
Glycine (marketed as Maapliv) was originally authorised in the EU for acute decompensation episodes of maple syrup urine disease (MSUD). The TxGNN model predicts it may be effective for nasal cavity disease, but this is a computational prediction only. The data compiled for this report contain 1 registered clinical trial (judged not relevant) and 2 publications (basic or preclinical, not relevant to glycine therapy).
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Treatment of maple syrup urine disease (MSUD) presenting with an acute decompensation episode in patients from birth who are not eligible for an oral or enteral BCAA-free formulation |
| Predicted New Indication | Nasal cavity disease |
| TxGNN Prediction Score | 99.85% |
| Evidence Level | L5 |
| EU Market Status | Cancelled only (no currently valid authorisation) |
| Number of Authorizations | 1 |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Currently, detailed mechanism of action data is not available. Glycine is a simple amino acid that acts as an inhibitory and co-agonist neurotransmitter and has general metabolic roles. In the authorised MSUD indication, its use is tied to metabolic management during acute decompensation rather than to any effect on the nose or airway tissue.
The data compiled for this report establish no credible mechanistic link between glycine and nasal cavity disease. The high TxGNN score (99.85%, rank 2574) comes from network-based modelling and is not backed by clinical or experimental evidence. The original and predicted indications (an inborn error of metabolism versus a disease of the upper airway) are biologically distant, and no similarity analysis could be supported.
A second prediction, acute laryngopharyngitis (score 99.84%), also has no trials or literature and the same Hold recommendation.
Clinical Trial Evidence
| Trial Number | Phase | Status | Enrollment | Key Findings |
|---|---|---|---|---|
| NCT01806675 | Phase 1/2 | Completed | 25 | PET/CT or PET/MRI imaging of αvβ3 integrin expression with a new radiotracer (18F-FPPRGD2) as an angiogenesis biomarker in glioblastoma, gynaecological cancers and renal cell carcinoma. This is a diagnostic imaging study; glycine is not a therapeutic intervention and it gives no support for nasal cavity disease. |
Literature Evidence
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 29607903 | 2018 | Preclinical formulation study | Chemical & Pharmaceutical Bulletin | Oligoarginine-polymer conjugates as mucosal adjuvants for nasal influenza vaccination in mice; not a study of glycine therapy |
| 7771054 | 1995 | Basic research | Veterinary Pathology | Lectin histochemistry of normal and herpesvirus-infected bovine nasal mucosa; not related to glycine treatment |
EU Market Information
| Authorization Number | Product Name | Dosage Form | Approved Indication |
|---|---|---|---|
| EMEA/H/C/005557 (status: cancelled) | Maapliv | Not specified | Treatment of maple syrup urine disease (MSUD) presenting with an acute decompensation episode in patients from birth who are not eligible for an oral and e… |
Safety Considerations
- Disease associations from the knowledge graph (not label text): The TxGNN knowledge graph lists contraindication links with the following conditions, which should be verified against official labelling before any use:
- Kidney and urinary: kidney disease, chronic kidney disease, chronic renal failure, end-stage renal failure, nephrolithiasis, nephrocalcinosis, acute urate nephropathy, pyoureter.
- Calcium, phosphate and parathyroid: hypercalcaemia, humoral hypercalcaemia of malignancy, hyperparathyroidism, osteitis fibrosa, hyperphosphataemia, phosphorus metabolism disease, hypervitaminosis, lytic metastatic bone lesion, sarcoidosis.
- Cardiovascular: heart disease, cardiovascular disease, arteriosclerosis obliterans, digitalis poisoning, ventricular fibrillation.
- Metabolic and other: phenylketonuria, disorders of phenylalanine metabolism, constipation.
No drug-interaction records were found. Please refer to the SmPC for formal warnings and contraindications.
Conclusion and Next Steps
Decision: Hold
Rationale: The prediction rests only on a model score. The single related trial is an unrelated imaging study, the literature is basic or preclinical, and no mechanistic link to nasal cavity disease can be established. The only EU authorisation for glycine (Maapliv) has been cancelled.
To proceed, the following is needed:
- Mechanism of action data (for example from DrugBank) and a plausible biological rationale for nasal cavity disease
- Official SmPC warnings and contraindications, so safety screening can be completed
- Preclinical or clinical studies that test glycine directly in nasal or upper-airway disease
- Assessment of route and formulation suitability (for example, topical or nasal), since the original product was an intravenous metabolic therapy
- Clarification of the regulatory status of glycine products in the EU
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.