In a proof-of-concept study, Lau et al. have shown that the treatment course of direct-acting antiviral agents (DAAs) can be reduced to 3 weeks and still be effective using a response-guided approach. Patients with chronic hepatitis C (genotype 1b) without cirrhosis were randomly allocated to receive one of three different triple DAA regimens: sofosbuvir, ledipasvir and asunaprevir (n = 12); sofosbuvir, daclatasvir and simeprevir (n = 6); or sofosbuvir, daclatasvir and asunaprevir (n = 8). Only those who demonstrated an ultra-rapid virologic response to DAAs by day 2 had their treatment course reduced from the standard 12 weeks to 3 weeks, achieving virologic ‘cure’ by week 3 with excellent tolerability. The authors hope that shortening the duration of therapy could substantially reduce treatment costs, but large-scale studies of this approach are needed.