Ioxitalamate meglumine

Ioxitalamate meglumine is a chemical substance classified as an iodinated contrast agent (ATC code V08AA05, ioxitalamic acid). It is already authorised as a medicine and is supplied by the company Guerbet under the trade name Telebrix Gastro, 300 mg I/ml, as a solution for oral or rectal use.^[1]

What is ioxitalamate meglumine?

Ioxitalamate meglumine is a chemically synthesised, iodine-containing contrast agent. Its registry name in the EU Clinical Trials Information System is IOXITALAMATE MEGLUMINE, and it is authorised as a medicine in Belgium (authorisation record BE147411).^[1] The product used in the trial is called Telebrix Gastro, 300 mg I/ml, described as a solution for oral or rectal administration.^[1] In the FAPIDO trial, ioxitalamate meglumine does not act as the medicine under investigation; it is listed as an auxiliary agent, meaning it supports the imaging procedure rather than being tested for a treatment effect.^[1]

How does ioxitalamate meglumine work?

Ioxitalamate meglumine belongs to a group of substances called iodinated contrast agents. These agents contain iodine, which absorbs X-rays strongly. When the solution is given by mouth or into the rectum, it coats the inside of the digestive tract. This makes the outline of the stomach, intestines and surrounding structures stand out more clearly on computed tomography (CT) scans. In the FAPIDO trial, the contrast agent is used together with positron emission tomography (PET) imaging to help define the digestive tract during scans with the investigational tracer [18F]AlF-FAPI-74.^[1]

Which conditions is it used or studied for?

Ioxitalamate meglumine is not a treatment for any disease. It is used as a diagnostic aid in imaging. In the FAPIDO trial, it is used in patients with the following conditions:

• Oesophagogastric adenocarcinoma (OGA) — a cancer of the junction between the oesophagus and the stomach, where the study measures how well the new tracer detects lymph node and distant metastases.
• Pancreatic ductal adenocarcinoma (PDAC) — the most common type of pancreatic cancer, where the same detection of lymph node and distant metastases is measured.
• Clinically challenging oncological situations — patients in whom standard imaging leaves doubt about whether a lesion is malignant, where the study records whether the new scan is considered contributory to the clinical decision.

How is ioxitalamate meglumine given?

Ioxitalamate meglumine is given as a solution for oral or rectal use. The product in the FAPIDO trial is Telebrix Gastro, 300 mg I/ml, and the trial record lists a volume of 100 millilitres given by mouth.^[1] It is not injected. The contrast agent is used to prepare the digestive tract before PET/CT imaging, while the investigational tracer [18F]AlF-FAPI-74 is given separately by intravenous administration at a dose of 600 megabecquerels.^[1]

What do the clinical trials show?

There is one registered clinical trial involving ioxitalamate meglumine in the EU Clinical Trials Information System. The trial is called FAPIDO and carries the EU CT number 2024-512059-19-00.^[1] It is a Phase 4, interventional, prospective, non-randomised, multicentre, multi-cohort study that plans to enrol 109 participants.^[1] The trial is currently authorised, meaning it has received regulatory approval but has not yet started recruiting according to the registry record.^[1]

The main goal of the trial is to compare the detection of lymph node and distant metastases between [18F]AlF-FAPI-74 PET/CT and standard imaging ([18F]FDG PET/CT or conventional imaging) in treatment-naïve, newly diagnosed patients with oesophagogastric adenocarcinoma (clinical stage T1-4N0-3M0) or pancreatic ductal adenocarcinoma (clinical stage T1-4N0-2M0-1).^[1] For patients with a clinically challenging situation, the study measures the fraction of patients in whom the new scan was deemed contributory to the clinical decision, for example by correctly identifying a lesion as malignant or non-malignant, or by resolving doubt between the two.^[1]

The trial description states that the aim is to demonstrate a superior detection ratio for [18F]AlF-FAPI-74 PET/CT compared with standard imaging, and to describe the clinical utility of the new tracer in patients with a clinically challenging situation.^[1] The study is described in the registry as a Phase II/III trial in its brief summary, while the structured phase field records it as Phase 4.^[1]

What side effects are known?

The registry record for this trial does not list side effects for ioxitalamate meglumine. No supplementary sources on side effects were provided.