BETHESDA, MD 09 Dec 2013—
and Gilead Sciences on December 6 announced the approval of sofosbuvir oral tablets as part of a regimen for the treatment of chronic hepatitis C virus (HCV) infection caused by viruses of genotypes 1, 2, 3, or 4.
Sofosbuvir is the third drug with breakthrough therapy status to be approved by FDA. The agency grants breakthrough status to drugs on the basis of preliminary clinical evidence that they may be substantially superior to existing therapies for serious or life-threatening diseases.
According to FDA, sofosbuvir is the first drug that can be used without an interferon product to treat certain types of chronic HCV infection. The drug may also be used in patients coinfected with HCV and HIV.
for sofosbuvir, marketed by Gilead as Sovaldi, describes it as an inhibitor of the hepatitis C virus NS5B RNA-dependent RNA polymerase, which is essential for viral replication.
The goal of combination therapy with sofosbuvir is to clear the HCV infection, and the recommended treatment regimen and duration depend on the viral genotype and patient characteristics.
For patients infected with HCV of genotype 1 or 4, the recommended treatment regimen is 12 weeks of triple therapy with sofosbuvir, peginterferon alfa, and ribavirin.
A 12-week course of dual therapy with sofosbuvir and ribavirin is recommended for patients with HCV genotype 2 infection, and 24 weeks of the dual therapy is recommended for patients with genotype 3 infection.
The labeling recommends 24 weeks of dual therapy in patients with genotype 1 infection who are "interferon ineligible," and up to 48 weeks of dual therapy in patients with hepatocellular carcinoma who are awaiting liver transplantation. Dual therapy should be discontinued once the patient receives a new liver.
Sofosbuvir is not recommended as monotherapy for the treatment of HCV infection.
The recommended dosage of sofosbuvir is one 400-mg tablet taken once daily with or without food. Dosage reductions are not recommended.
Included in the labeling for sofosbuvir are instructions for reducing the dosages of ribavirin and peginterferon in response to adverse events that may be associated with those drugs.
Dual therapy with ribavirin and peginterferon alfa has been associated with embryofetal toxicity, and pregnancy must be avoided during treatment, according to the labeling for sofosbuvir.
In clinical trials, the most frequently reported adverse events in patients receiving sofosbuvir and ribavirin were fatigue and headache. In patients treated with sofosbuvir, ribavirin, and peginterferon alfa, the most frequently reported adverse events were fatigue, headache, insomnia, and anemia.
Sofosbuvir is packaged in 28-tablet bottles containing a desiccant. The drug should be dispensed in the original container only and stored below 30 °C.