Madsen LW, Christensen PB, Fahnøe U, et al. - The present study was performed to correlate four weeks of glecaprevir/pibrentasvir (GLE/PIB) treatment with and without ribavirin for patients with chronic hepatitis C and favorable baseline characteristics, and to monitor the development of resistance-associated substitutions (RAS) and re-treatment outcomes if treatment failed. An open-label single center randomized controlled trial was designed to include patients with chronic hepatitis C who were assigned randomly in a 1:1 ratio to GLE/PIB +/- ribavirin, stratified by genotype 3. Researchers ascertained viral genome sequences by deep sequencing at baseline and at the time of relapse. The study enrolled a total of 32 patients and started treatment. Results demonstrate that baseline RAS were more frequent in patients with virological failure in this pilot study of four-week treatment with GLE/PIB with and without ribavirin. It was shown that development of RAS did occur after short treatment but did not result in retreatment failure with a different regimen.