Our lead product candidate, RTT01, is under development for the treatment of several conditions of thyroid hormone signalling dysfunction. Thyroid hormone is a key metabolic regulator in the human body with effects on almost all cell types and plays an important role in the development and proper function of multiple organs. To adequately perform its normal role, thyroid hormone needs to be produced correctly and in the right amount, transported to its place of activity and ultimately bind successfully to its receptor within the cell nucleus. A disruption in any of these steps will impair the body’s possibility to adequately perform and regulate thyroid hormone signalling and cause dysfunction of various cells and organs with different symptoms depending on the type and nature of the defect.
We are currently evaluating RTT01 in clinical trials for the treatment of MCT8 deficiency, a rare inborn error of thyroid hormone signalling. This devastating condition is caused by genetic mutations that result in inadequate activity of a key thyroid hormone transporter called MCT8. This results in a complex clinical picture with symptoms of both under and over signalling of thyroid hormone in different cells and organs, together resulting in a very severe syndrome with significant impact on the patients’ lives. A first clinical trial in patients suffering from MCT8 deficiency of all ages has been concluded with significant and clinically relevant results. A second clinical trial looking at early intervention in very young affected children is about to start later this year.