Erasmus Universitair Medisch Centrum Rotterdam (Erasmus MC)
Responsive
Rotterdam, The Netherlands
Not recruitingRare disease
Study of Tiratricol Treatment Withdrawal in Males with MCT8 Deficiency (Monocarboxylate Transporter 8 Deficiency)
Verified siteInvestigational
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What is this trial about?
A plain-language summary of the goals, design and what participants do
This study focuses on Monocarboxylate Transporter 8 (MCT8) deficiency, a rare genetic condition that affects how thyroid hormones move through the body. The research examines the effects of a medication called tiratricol, which is a thyroid hormone-like substance taken as tablets, in male patients who have been diagnosed with this condition.
The purpose of this research is to understand what happens when some patients stop taking tiratricol and receive a placebo instead, while others continue their regular tiratricol treatment. The study will specifically look at the levels of thyroid hormones in the blood and determine if patients who stop taking tiratricol need to restart the treatment.
During the study, participants will be randomly divided into two groups. One group will continue taking tiratricol tablets, while the other group will receive placebo tablets. The treatment period will last for 30 days, during which various measurements will be taken, including blood tests to check thyroid hormone levels, heart function monitoring, and general health assessments. The study includes regular check-ups to ensure participant safety throughout the treatment period.
The research process
The trial runs in 5 steps – from screening to follow-up. Each step says what happens and what the team monitors.
Who can join the trial?
5 criteria
- Must be male with confirmed MCT8 gene mutation (proven by genetic testing)
- Must have elevated levels of T3 hormone (thyroid hormone) above the normal range either:
- At the time of diagnosis before starting tiratricol treatment, or
- During the screening visit (for those who have never taken tiratricol or have stopped other medications)
- Must be at least 4 years old when starting the study (children who will turn 4 by the study start may be considered)
- Must have parent or legal guardian consent through a signed and dated form
Who cannot join the trial?
10 criteria
- Being female (only male participants are eligible)
- Age under 18 years or over 65 years old
- Not having a confirmed diagnosis of MCT8 deficiency
- Not currently taking a stable dose of tiratricol (a thyroid hormone medication)
- Having any serious medical conditions that could interfere with the study procedures
- Being unable to comply with study procedures or follow-up visits
- Having participated in another clinical trial within the past 30 days
- Having any known allergies to tiratricol or similar medications
- Having significant abnormalities in blood tests that could affect safety
- Being unable to provide informed consent
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Investigated drugs
Tiratricol is a medication that helps regulate thyroid hormone levels in patients with MCT8 deficiency, a rare genetic condition affecting thyroid hormone transport. This medication is particularly important for managing high T3 hormone levels in the blood of patients with this condition. It works by helping to normalize thyroid hormone function in the body. The medication helps improve symptoms associated with MCT8 deficiency, which is a condition that primarily affects males.
What is already known about the treatment
Tiratricol - A thyroid hormone analog administered orally that is being studied in the treatment of Monocarboxylate Transporter 8 (MCT8) deficiency, a rare genetic condition affecting thyroid hormone transport. The medication works by mimicking the effects of thyroid hormones in the body, particularly helping to regulate metabolism and development in patients with MCT8 deficiency. As a synthetic thyroid hormone derivative, it belongs to the pharmacological class of thyroid hormone receptor agonists and is currently being evaluated in clinical trials to assess its effectiveness when used as a maintenance therapy for male patients with MCT8 deficiency.
Investigated diseases
Monocarboxylate Transporter 8 (MCT8) Deficiency - A rare genetic condition that affects the body's ability to transport thyroid hormones into cells. The condition primarily affects males and is caused by mutations in the MCT8 gene, which is responsible for moving thyroid hormones across cell membranes. People with MCT8 deficiency have abnormal thyroid hormone levels in their blood, with typically high T3 levels. This disorder affects brain development and function, leading to developmental delays and movement difficulties. The condition becomes apparent in early infancy, with affected individuals showing problems with muscle control and movement.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2024-516124-34-00Protocol codeMCT8-2021-3Estimated enrolment10 patientsSponsorRare Thyroid Therapeutics International AB
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