Gilead Sciences, Inc., announced in late April the results from four Phase 3 clinical trials (called NEUTRINO, FISSION, POSITRON and FUSION) to evaluate sofosbuvir (nucleotide NS5B inhibitor), the company’s investigational once-daily pill-form therapy for the treatment of chronic hepatitis C virus (HCV) infection. Sofosbuvir, a direct-acting agent, works by interrupting the HCV life cycle by suppressing viral replication.
The results were presented in oral sessions at the 48th Annual Meeting of the European Association for the Study of the Liver (International Liver Congress 2013), April 24-28, 2013, in Amsterdam, The Netherlands. Findings from the studies were also published online in two papers and ahead of print in The New England Journal of Medicine on April 23.
In the four trials, sofosbuvir was administered to nearly 1,000 patients with chronic HCV infection as part of an all-oral 12-week or 16-week treatment regimen, in combination with ribavirin (RBV) in genotypes 2 and 3, or with RBV and pegylated interferon (peg-IFN) for 12 weeks in genotypes 1, 4, 5 and 6.
Investigators observed sustained viral response (SVR) rates 12 weeks after completing therapy that ranged from 50% to 90%. SVR signals that a patient has “cleared” the virus for at least six months after completing therapy. It is achieved when viral levels drop, becoming nearly undetectable. Patients who achieve SVR are considered cured of their HCV infection.
Adverse events were mild and included fatigue, nausea, headache, anemia and dizziness. Less than 2% of patients in the sofosbuvir treatment groups discontinued the study due to side effects.
“There remains an urgent unmet medical need for individuals diagnosed with chronic hepatitis C infection,” commented Ira Jacobson, MD, Chief of the Division of Gastroenterology and Hepatology, Vincent Astor Distinguished Professor of Medicine, The Joan Sanford I. Weill Medical College of Cornell University, Attending Physician, New York-Presbyterian Hospital Cornell Campus. “The breadth of data from the Phase 3 program evaluating sofosbuvir will help physicians understand how to treat the disease in the future across various HCV genotypes and patient populations.”
Source: Gilead news release dated April 30, 2013