Used in the treatment of hepatitis C, this compound acts as a deuterated analog of sofosbuvir's active metabolite, enhancing metabolic stability and improving pharmacokinetic properties. It is studied for its ability to increase the half-life of the active antiviral agent, allowing for lower dosing and reduced side effects. Its deuterated structure slows down degradation in the liver, making it more effective in inhibiting the RNA polymerase of the hepatitis C virus. It has been part of research into next-generation nucleotide analogs for improved antiviral therapies.