Sofosbuvir Works for Patients Who Cannot Take Peginterferon

In patients infected with hepatitis C virus (HCV) genotype 2 or 3, treatment with peginterferon plus ribavirin has a sustained virologic response (SVR) of 70% to 85%. However, adverse effects of peginterferon are a barrier to treatment for many patients. Now, two industry-funded, phase III trials have evaluated the efficacy of sofosbuvir (400 mg daily) plus ribavirin (1000 mg–1200 mg daily) in these patients.

In a blinded, placebo-controlled trial, investigators randomized 280 patients for whom peginterferon therapy was not an option (e.g., adverse effects, contraindications for interferons, and patient refusal) to receive sofosbuvir/ribavirin or matching placebo for 12 weeks. In a blinded, active-control trial, researchers randomized 202 patients with prior nonresponse to peginterferon therapy to receive 12 or 16 weeks of sofosbuvir/ribavirin. The primary endpoint in both studies was SVR at 12 weeks after therapy ended.

In patients for whom peginterferon therapy was not an option, SVR was 78% for treatment with sofosbuvir/ribavirin compared with 0% for placebo (P<0.001). In previously treated patients, SVR was 50% for 12 weeks of therapy versus 73% for 16 weeks (P<0.001). SVR rates were lower for patients with genotype 3 versus genotype 2 in both treatment-naive patients (61% vs. 93%) and treatment-experienced patients who received therapy for 12 weeks (30% vs. 86%) or 16 weeks (62% vs. 94%).

SVR rates were lower in patients with cirrhosis than without, both in treatment-naive patients (overall, 61% vs. 81%; genotype 3 vs. 2, 21% vs. 94%) and treatment-experienced patients (overall, 66% vs. 76%; genotype 3 vs. 2 in 16-week group, 61% vs. 78%). In both studies, investigators found no evidence of resistance development, and discontinuation rates were low (1%–2%).