Hepatitis C currently infects more than 170 million people around the world, leading to significant morbidity and mortality. The current standard of care for HCV infection, including one of the two protease inhibitors, telaprevir or boceprevir, for 12-32 weeks, along with pegylated interferon alfa-2a (PEG-IFN-α) and ribavirin for up to 48 weeks, is unsatisfactory in many cases, either because of lack of efficacy or because of treatment-related adverse effects. There is an urgent need of new drugs with improved efficacy as well as a safety profile. Sofosbuvir, a recently approved nucleotide analog, is a highly potent inhibitor of the NS5B polymerase in the Hepatitis C virus (HCV), and has shown high efficacy in combination with several other drugs, with and without PEG-INF, against HCV. It offers many advantages due to its high potency, low side effects, oral administration, and high barrier to resistance. The efficacy and safety were demonstrated in many large and well-designed phase 2 and phase 3 clinical trials like NEUTRINO, PROTON, ELECTRON, ATOMIC, COSMOS, FUSION, FISSION, NUCLEAR, POSITRON, and the like. It is generally well-tolerated. Adverse events that occurred include: Headache, insomnia, fatigue, nausea, dizziness, pruritis, upper respiratory tract infections, rash, back pain, grade 1 anemia, and grade 4 lymphopenia; however, the exact safety profile can only be judged when this drug is actually used on a large scale.
Keywords: Hepatitis C; NS5B polymerase; SVR; sofosbuvir.