Discovery of SYD5115, a novel orally active small molecule TSH-R antagonist

Area of Science:

• Endocrinology
• Pharmacology
• Drug Discovery

Background:

• The thyrotropin receptor (TSH-R) is crucial for thyroid gland function.
• Graves' disease involves TSH-R overstimulation by autoantibodies, causing hyperthyroidism.
• Existing treatments may have limitations, necessitating novel therapeutic approaches.

Purpose of the Study:

• To discover and characterize novel small molecule antagonists of the TSH-R.
• To evaluate the efficacy of these antagonists in blocking TSH-R activity and thyroid hormone synthesis.
• To address challenges in compound optimization, including metabolic stability and potential mutagenicity.

Main Methods:

• High-throughput screening and medicinal chemistry for small molecule discovery.
• In vitro assays to assess TSH-R binding and antagonism.
• In vivo studies to evaluate the efficacy of lead compounds in blocking thyroid hormone (T4) synthesis.
• Assessment of compound metabolic stability and mutagenicity profiles.

Main Results:

• Discovery of SYD5115, a potent TSH-R antagonist with nanomolar activity.
• SYD5115 demonstrated efficacy in blocking stimulating antibody-induced T4 synthesis in vivo after a single oral dose.
• Optimization efforts addressed initial challenges with metabolic stability and potential mutagenicity of early compounds.

Conclusions:

• SYD5115 represents a promising novel small molecule antagonist for the TSH-R.
• The compound shows potential for treating conditions like Graves' disease by inhibiting thyroid hormone production.
• Further development is warranted to optimize its pharmacological properties for therapeutic use.