P037: In vitro evaluation of drug–drug interaction potential of doxecitine and doxribtimine in thymidine kinase 2 deficiency (TK2d)

Doxecitine and doxribtimine powder for oral solution is a 1:1 mixture by weight of deoxycytidine (dC) and deoxythymidine (dT). It is being investigated as a treatment for patients with thymidine kinase 2 deficiency (TK2d), an ultra-rare genetic mitochondrial disease associated with progressive proximal myopathy and respiratory weakness. Here, we report findings on the in vitro plasma protein binding and potential interactions of doxecitine and doxribtimine with cytochrome P450 (CYP) enzymes and common drug transporters.