A 12-week, ribavirin-free regimen achieved sustained virologic response for 85% of patients with genotype 1 hepatitis C virus (HCV) infection, researchers reported in the February issue of Gastroenterology.
“This represents one of the first applications of a highly effective HCV regimen outside clinical trials,” said Dr. Mark S. Sulkowski of John Hopkins University in Baltimore and his associates. Adding ribavirin to the simeprevir and sofosbuvir combination regimen did not improve sustained virologic response (SVR), but patients were less likely to achieve it if they had cirrhosis, current or prior hepatic decompensation, or a history of failing other protease inhibitors, the investigators said.
Dr. Mark S. Sulkowski
Novel hepatitis C therapies have yielded “substantially lower” rates of SVR and more side effects in everyday practice than in clinical trials, the investigators noted. To better understand how some of newest HCV drugs perform in the real world, they conducted an observational cohort study of the safety, tolerability, and efficacy of simeprevir plus sofosbuvir for treating genotype 1 HCV infections in academic and nonacademic settings (HCV-TARGET) (Gastroenterology 2015 doi: 10.1053/j.gastro.2015.10.013).
A total of 836 patients received once-daily simeprevir (150 mg) and sofosbuvir (400 mg), and 169 of them also received ribavirin. Most (61%) patients had genotype 1a infection and were white (76%), male (61%), and cirrhotic (59%); 13% were black. Patients usually were treatment experienced, having failed peginterferon and ribavirin either with (12%) or without (46%) telaprevir or boceprevir, the researchers said.
In all, 675 (84%) patients achieved SVR after 12 weeks of treatment (SVR12; 95% confidence interval, 81%-87%). Adding ribavirin to the combination PI regimen did not improve SVR, regardless of cirrhosis status, genetic subtype, or treatment history. However, crude SVR12 rates were only 75% for patients with hepatic decompensation and 81% for those with cirrhosis, and these patients had significantly lower adjusted odds of achieving SVR, compared with other patients. In hindsight, decompensated and cirrhotic patients might have needed 24 weeks of treatment, as the Food and Drug Administration now recommends based on the COSMOS trial results (Lancet. 2014;384[9956]:1756-65), the investigators said.
The adjusted model did not uncover a link between genotype 1 subtype and SVR, but only about 10% of patients were tested for the Q80K polymorphism, which is more common in genotype 1a infections and is associated with treatment resistance, the investigators noted. Crude SVR12 rates were 92% for patients with genotype 1b infection and 86% for those with 1a infection, they said.
Only 3% of patients stopped treatment; 2% did so because of side effects, and ribavirin did not significantly affect rates of treatment discontinuation, said the investigators. The most common side effects were fatigue, headache, nausea, rash, and insomnia. Serious adverse events affected 5% of patients and included gastrointestinal bleeding (0.5%), hepatic failure or encephalopathy (1.2%), and infections (1.1%).
Taken together, these results show that simeprevir and sofosbuvir effectively translate from the clinical trial setting into clinical practice, said the researchers. “Additional research is needed to understand which patients may benefit from different treatment regimens or longer treatment durations,” they emphasized.
The study was supported by the University of Florida at Gainesville, the University of North Carolina at Chapel Hill, AbbVie, Bristol-Myers Squibb, Gilead, Janssen, Kadmon, Merck, Vertex, and the National Institutes of Health. Dr. Sulkowski reported grants and personal fees from Gilead, Janssen, Achillion, Abbvie, Merck, and Bristol-Myers Squibb. Of 14 coinvestigators, 13 reported financial relationships with a number of pharmaceutical companies.