Abstract: Objective The aim of this study was to investigate the clinical antiviral efficacy of dalatavir (DCV) and asulivir (ASV) combination in the treatment of naïve patients with chronic hepatitis C (CHC) with genotype 1b infection. Methods 53 naïve patients with CHC and genotype 1b infection were enrolled in our hospital between October 2019 and October 2021, and all of them received the combination regimen of DCV and ASV therapy for 24 weeks, and were followed-up for 24 weeks. Serum HCV RNA loads, blood biochemical indexes and liver fibrosis index levels were detected. The drug resistance-related mutations of NS5A were detected by direct sequencing. Results At week 1, 2, 4, 8, 12 and 24 treatment, and at the end of 24 week follow-up, serum HCV RNA loss rates in the 53 patients with CHC were 3.7%, 9.4%, 43.3%, 69.8%, 83.0%, 94.3% and 94.3%, and serum HCV RNA loads were (5.8±0.1)lg IU/ml, (5.3±0.6)lg IU/ml, (3.5±0.5)lg IU/ml, (2.2±0.6)lg IU/ml, (1.0±0.2)lg IU/ml, (0.7±0.5)lg IU/ml and (0.7±0.4)lg IU/ml, all significantly lower than [(6.1±0.4)lg IU/ml, P＜0.05] at baseline; at treatment week 24 and at the end of follow-up, serum AST levels were (22.7±11.4)U/L and (20.9±9.9)U/L, both significantly lower than [(63.5±6.6)U/L, P<0.05], and serum ALT levels were (19.3±10.7)U/L and (19.2±8.5)U/L, both significantly lower than [(80.2±65.3)U/L, P＜0.05] at baseline; there were no obvious changes as respect to estimated glomerular filtration rate and blood routines during the treatment; at the end of treatment and follow-up, serum liver fibrosis indexes, such as Pc-III, HA and IV-c levels decreased greatly (P＜0.05); the drug resistance-related mutations of NS5A was found in 3 cases (5.6%), out of which, the L31Y and Y93H simultaneous mutation in one case, and Y93H mutation in two cases. Conclusion The combination of DAC and ASV in treatment of naïve patients with CHC with genotype 1b infection is definitely efficacious, without renal function injury, while the NS5A mutations needs further investigation.

Key words: Hepatitis C, Genotype 1b, Dalatavir, Asurivir, Therapy, Naïve