In short
D-Glucose-13C6 is an investigational diagnostic substance being studied in a Phase 2 clinical trial for people with paraganglioma or pheochromocytoma who are scheduled for surgery. The trial, authorised in the EU under number 2023-506001-19-00, plans to enroll 10 participants. It is testing whether a specific metabolic profile of this labelled glucose can serve as a new biomarker for detecting mutations in SDHx genes.
Key points
- D-Glucose-13C6 is a form of glucose labelled with a non-radioactive carbon isotope (carbon-13) used as an investigational diagnostic tracer.
- The only registered trial is a Phase 2 interventional study authorised in the European Union.
- The trial investigates people with paraganglioma or pheochromocytoma who have a surgical indication.
- Planned enrollment is 10 participants.
- The trial measures whether a 13C6-glucose metabolism profile in plasma can indicate the presence of an SDHx gene mutation.
- The trial status is Authorised, meaning it has regulatory approval to proceed.
What is D-Glucose-13C6?
D-Glucose-13C6 is an investigational diagnostic substance. It is a form of glucose — the sugar that cells use for energy — in which all six carbon atoms have been replaced with the stable, non-radioactive isotope carbon-13. In the registry records for the authorised trial, the substance appears only under this name, with no trade names or development codes listed. D-Glucose-13C6 has no marketing authorisation in these records and is being investigated as a potential biomarker tool rather than as a treatment.
How does D-Glucose-13C6 work?
The trial is based on the idea that cells with a mutation in one of the SDHx genes process glucose differently from cells without such a mutation. SDHx genes code for subunits of the enzyme succinate dehydrogenase, which is involved in energy production inside cells. When a person receives D-Glucose-13C6 intravenously, the labelled glucose enters metabolic pathways. The trial measures whether the pattern of labelled glucose breakdown products in plasma — a "13C6-glucose metabolism profile" — differs between people who carry an SDHx mutation and those who do not.
Which conditions is D-Glucose-13C6 being studied for?
The authorised trial focuses on one disease area: rare neuroendocrine tumors. Specifically, it includes people with one of two related conditions:
- Paraganglioma — a rare tumor that arises from nerve cells outside the adrenal gland, often in the neck, chest, or abdomen.
- Pheochromocytoma — a rare tumor of the adrenal gland that can produce excess hormones affecting blood pressure and heart rate.
Both tumor types can occur in people who carry inherited mutations in SDHx genes, and identifying such mutations can influence follow-up and family screening.
How is D-Glucose-13C6 given?
In the registered trial, D-Glucose-13C6 is given as a single intravenous dose of 24 grams. The substance is administered as a solution for intravenous use, meaning it is delivered directly into a vein. This route allows the labelled glucose to enter the bloodstream rapidly so that its metabolic products can be measured in plasma.
What do the clinical trials show?
One trial of D-Glucose-13C6 is registered in the EU Clinical Trials Information System. It is a Phase 2, interventional study with the title "SDH-FLUX - Development of a new biomarker for tumor development in patients with SDHx mutation by in vivo fluxomics". The trial is currently authorised, meaning it has received regulatory approval and may proceed to enroll participants. Planned enrollment is 10 participants.
The main outcome measured is the presence or absence of a specific 13C6-glucose metabolism profile in patients' plasma. The trial aims to determine the sensitivity and specificity of this profile as a marker for a constitutional mutation in one of the SDHx genes, compared with genetic testing as the reference standard. In other words, the study asks how well the glucose-based test can correctly identify people who do and do not carry an SDHx mutation.
Who can take part in the trial?
The trial includes people diagnosed with paraganglioma or pheochromocytoma who have a surgical indication, meaning their tumor is planned to be removed by surgery. The registry record does not list further detailed eligibility criteria such as age limits or exclusion conditions. Because the study compares the glucose metabolism profile with genetic testing results, participants' genetic status is a central part of the analysis.