Excellent outcome of direct antiviral treatment for chronic hepatitis C in Switzerland

2018 Swiss Medical Weekly 148;(w14560)

BACKGROUND: The introduction of direct acting antivirals (DAAs) for the therapy of chronic hepatitis C (CHC) has revolutionised treatment and marks a paradigm shift in the approach to this disease, rendering interferon-based therapies obsolete. AIMS OF THE STUDY: We retrospectively and prospectively evaluated treatment results after the introduction of DAA in Switzerland in a cohort of patients with CHC. METHODS: We examined 565 patients who received DAA treatment for CHC between November 2013 and June 2016 with regard to HCV genotype, fibrosis stadium, treatment and outcome. In addition, outcome of re-treatment and resistance-associated substitutions (RAS) in patients that did not achieve sustained virological response (SVR) were evaluated. The majority of patients participate in the Swiss Hepatitis C Cohort Study. Data were evaluated in an intention-to-treat and a modified intention-to-treat analysis. RESULTS: Overall SVR rate for all patients was 94% (530 of 565, 95% CI 92-96%). Of 350 patients with HCV genotype 1 CHC, 335 achieved SVR, resulting in an SVR rate of 96% (335 of 350, 95% CI 94-98%). Patients with HCV genotype 2 achieved SVR in 94% (48 of 51, 95% CI 87-100%). Patients with HCV genotype 3 showed SVR of 92% (98 of 107, 95% CI 87-97%). In patients with HCV genotype 4, the SVR rate was substantially lower at 85% (49 of 57, 95% CI 76-94%). The rate of advanced liver fibrosis (Metavir F3/F4) assessed by means of liver biopsy or Fibroscan(R) in the entire patient population was 71% (404 of 565). Out of 35 patients that did not achieve SVR after DAA treatment, 32 had a relapse and 3 patients showed viral breakthrough. In 17 of 35 cases (49%) patients were treatment naive and 21 of 35 patients (60%) were cirrhotic. RAS genotyping of HCV was performed in 14 patients. Nine of these 14 patients (60%) carried mutations in the NS5A region of the virus genome. Twenty-seven percent of patients who experienced treatment failure were not treated with recommended regimens as a result of drug availability and reimbursement limitations. CONCLUSION: In Switzerland, novel DAA treatments for CHC reflect the positive results from registration trials. Genotypes 2 and 4 remained more difficult to treat between 2014 and 2016. Patients who experienced a relapse after DAA treatment in Switzerland predominantly showed mutations in the NS5A region of the virus genome. DAA treatment limitations in Switzerland did prevent optimal treatment regimens in some patients.