Doxecitine and doxribtimine for treating thymidine kinase 2 deficiency

Doxecitine and doxribtimine is in development for the treatment of thymidine kinase 2 deficiency (TK2d). Thymidine kinase 2 (TK2) is a protein involved in the normal function of mitochondria. Mitochondria produce energy in the cells of the body. TK2d leads to abnormally low amounts of DNA in mitochondria and because of this defect, the mitochondria are not able to provide the energy that cells need to function properly. This causes severe muscle weakness, along with a host of additional symptoms that may involve breathing, feeding, and walking, and can progress until patients lose many of these abilities, resulting in death. There are no approved pharmacological treatment options for TK2d. Treatment is usually aimed at managing symptoms as they present.