Glutamic Acid
| Evidence Level: L4 | Predicted Indications: 4 |
Table of Contents
Glutamic Acid: From Maple Syrup Urine Disease to Postmenopausal Osteoporosis
One-Sentence Summary
Glutamic acid (marketed as Maapliv) was originally authorised in the EU for acute decompensation episodes of maple syrup urine disease (MSUD) in patients who cannot take an oral or enteral BCAA-free formulation. The TxGNN model predicts it may be effective for postmenopausal osteoporosis, but there are 0 registered clinical trials and only indirect literature (one animal study and one small human calcium-absorption study of a polymer derivative) supporting this direction. This is a computational prediction with very limited evidence.
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 and enteral BCAA-free formulation |
| Predicted New Indication | Postmenopausal osteoporosis |
| TxGNN Prediction Score | 99.34% |
| Evidence Level | L4 |
| EU Market Status | Cancelled only (no currently valid authorisation) |
| Number of Authorizations | 1 (cancelled) |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Currently, detailed mechanism of action data is not available. Glutamic acid is a naturally occurring amino acid, and its authorised use in MSUD is metabolic and nutritional in nature. No direct mechanistic bridge from that indication to bone metabolism can be drawn from the data compiled for this report.
Indirect support is weak. In ovariectomized mice, glutamic acid ameliorated estrogen deficiency-induced menopausal-like symptoms (PMID 26144993). A small human study found that poly-gamma-glutamic acid, a polymer derivative rather than glutamic acid itself, acutely enhanced calcium absorption in postmenopausal women (PMID 18187428). Neither study measured bone endpoints such as bone mineral density or fractures for glutamic acid itself.
Several other retrieved papers concern vitamin K2 or D3, whose effects involve glutamic acid residues in bone proteins, as well as genetic or metabolomic associations. These do not test glutamic acid as a treatment. The very high TxGNN score is a computational prediction only and should not be read as evidence of efficacy.
Clinical Trial Evidence
Currently no related clinical trials registered.
Literature Evidence
Only publications that involve glutamic acid or a direct derivative are listed as relevant. The remaining retrieved papers (vitamin K2/D3 studies, genetic and metabolomic associations, traditional medicine) do not test glutamic acid.
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 18187428 | 2007 | Human acute physiological study | J Am Coll Nutr | Poly-gamma-glutamic acid (a polymer derivative) on calcium absorption in postmenopausal women; first human study of this effect |
| 26144993 | 2015 | Animal study | Nutr Res | Glutamic acid ameliorated estrogen deficiency-induced menopausal-like symptoms in ovariectomized mice |
| 34529430 | 2021 | Preclinical drug delivery | Nano Lett | Bone-targeting polymer vesicles built from a glutamic acid-containing polymer for estradiol delivery; glutamic acid is a material component, not the therapeutic |
| 19172219 | 2009 | Randomized open-label study (109 patients) | J Bone Miner Metab | Menatetrenone (vitamin K2) increased osteocalcin gamma-carboxylation in postmenopausal osteoporosis; not a glutamic acid study |
| 14529146 | 2003 | Clinical review | Keio J Med | Vitamin D3 and/or K2 treatment for postmenopausal osteoporosis; not a glutamic acid study |
| 14584089 | 2003 | Clinical review | Yonsei Med J | Vitamin K2 plus bisphosphonate in postmenopausal osteoporosis; not a glutamic acid study |
EU Market Information
| Authorization Number | Product Name | Dosage Form | Approved Indication |
|---|---|---|---|
| EMEA/H/C/005557 (cancelled) | Maapliv | Not specified | Maapliv is indicated for the 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 enteral branched-chain amino acids free (BCAA- free)… |
Safety Considerations
- Knowledge-graph contraindication signals (from drug-disease contraindication edges, not label text): kidney disease (including chronic kidney disease, chronic renal failure and end-stage renal failure), nephrolithiasis and nephrocalcinosis, acute urate nephropathy, hypercalcemia and related calcium disorders (hyperparathyroidism, humoral hypercalcemia of malignancy, osteitis fibrosa, sarcoidosis), phosphorus metabolism disease, heart disease and cardiovascular disease, digitalis poisoning, ventricular fibrillation, and phenylketonuria or other disorders of phenylalanine metabolism.
- Drug Interactions (5 moderate-level interactions): amphetamine, benzphetamine, dextroamphetamine, lisdexamfetamine and metamfetamine.
Several of these signals, especially kidney disease, nephrolithiasis and calcium disorders, overlap with comorbidities common in an osteoporosis population and warrant careful review. Please refer to the SmPC for label-based warnings and contraindications.
Other Predicted Indications (for reference)
| Predicted Indication | TxGNN Score | Evidence Level | Assessment |
|---|---|---|---|
| Pregnancy associated osteoporosis | 99.18% | L5 | No trials or literature; likely reflects network proximity to postmenopausal osteoporosis; would need a separate pregnancy safety review. Hold |
| Primary hereditary glaucoma | 99.13% | L5 | No trials or literature; glutamate excitotoxicity is a recognised mechanism in retinal ganglion cell injury, so supplementation is mechanistically counterintuitive and potentially harmful. Hold |
| Gastroparesis | 99.11% | L5 | No trials; retrieved papers concern GAD65 autoantibodies, not glutamic acid as a therapy, and appear to be a name-matching artifact. Hold |
Conclusion and Next Steps
Decision: Hold
Rationale: The prediction rests on a computational score alone. There are no registered clinical trials, the only supportive literature is one animal study and one acute calcium-absorption study of a polymer derivative, and no mechanism links the original MSUD indication to bone metabolism. The only EU authorisation is cancelled, and the knowledge-graph contraindication signals (renal, calcium and cardiovascular disorders) need careful review.
To proceed, the following is needed:
- Mechanism of action data and a plausible pathway linking glutamic acid to bone remodelling
- Label-based warnings and contraindications from the SmPC
- Preclinical studies of glutamic acid itself with bone endpoints (bone mineral density, turnover markers)
- Safety evaluation covering renal function, calcium handling and cardiovascular risk in postmenopausal women
- Assessment of formulation and route, since the original product was an intravenous acute-care formulation
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.