Withdrawal of Tiratricol Treatment in Males With Monocarboxylate Transporter 8 Deficiency (MCT8 Deficiency)

Summary

This is a double-blind, randomized phase 3 multicenter placebo-controlled study in at least 16 evaluable male participants diagnosed with MCT8 deficiency. Male participants, from 4 years of age (at randomization) and having demonstrated stable maintenance treatment with tiratricol, will be randomized to receive placebo or tiratricol for 30 days or until reaching the rescue criterion (serum total triiodothyronine \[T3\] \> upper limit of normal \[ULN\] of the participant's normal range, for a sample collected during the 30-day Randomized Treatment Period). The research hypothesis to be tested is that, for participants in the placebo group, removal of tiratricol will lead to an increase of serum total T3 concentration, measured by liquid chromatography with tandem mass spectrometry (LC/MS/MS), above the ULN and requirement of rescue treatment with tiratricol, compared to those who continue to receive tiratricol.

Conditions

• Monocarboxylate Transporter 8 Deficiency
• Allan-Herndon-Dudley Syndrome

Interventions

DRUG

Tiratricol

Tiratricol tablets are flat tablets that contain 350 µg tiratricol. Treatment will be administered orally or via percutaneous endoscopic gastrostomy (PEG) tube; tablets will be suspended in water and, if needed, mixed with mashed food for oral administration or administered in water through the PEG tube as applicable.

DRUG

Placebo

Placebo tablets will be identical in appearance to tiratricol tablets but contain no tiratricol. Treatment will be administered orally or via PEG tube; tablets will be suspended in water and, if needed, mixed with mashed food for oral administration or administered in water through the PEG tube as applicable. During the Randomized Treatment Period, participants will receive the same number of tablets as the stable dose of open-label tiratricol they were receiving before randomization.

Sponsors & Collaborators

• Premier Research

  collaborator OTHER

• Egetis Therapeutics

  collaborator INDUSTRY

• Rare Thyroid Therapeutics International AB

  lead INDUSTRY

Principal Investigators

• Andrew J. Bauer, MD · Children's Hospital of Philadelphia

• W. E. Visser, MD · Erasmus Medical Center

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

QUADRUPLE

Model

PARALLEL

Eligibility

Min Age

4 Years

Sex

MALE

Healthy Volunteers

No

Timeline & Regulatory

Start

2023-07-21

Primary Completion

2025-07-22

Completion

2025-09-03

FDA Drug

Yes

Countries

• United States
• Netherlands
• United Kingdom

Study Locations