Efficacy and Safety of Ravidasvir Plus Sofosbuvir in Chronic Hepatitis C Infected Subjects Without Cirrhosis or with Compensated Cirrhosis: Interim Analysis Results of a Two-Stage, Open-Label, Multicentre, Phase 2/3 Trial

Background: In low- and middle-income countries, affordable direct-acting antivirals are urgently needed to treat hepatitis C virus (HCV) infection. The combination of ravidasvir, a pangenotypic NS5A inhibitor, and sofosbuvir has shown efficacy and safety in chronically HCV infected patients with genotype (GT) 4. The STORM-C-1 trial aims to assess the efficacy and safety of sofosbuvir plus ravidasvir in a more diverse population of adults chronically infected with HCV. Methods: STORM-C-1 is a two-stage, open-label, multicentre clinical trial in Malaysia and Thailand. HCV infected subjects with compensated cirrhosis (Metavir F4 and Child-Turcotte-Pugh class A) or without cirrhosis (Metavir F0-F3)  were eligible to participate, regardless of HCV genotype, HIV infection status, prior interferon-based HCV treatment or source of HCV infection. Stage 1 results are reported here. Once-daily ravidasvir (200mg) and sofosbuvir (400mg) were prescribed for 12 (without cirrhosis) or 24 (with cirrhosis) weeks. The primary endpoint was sustained virologic response at 12 weeks post-treatment (SVR12). This trial is registered with ClinicalTrials.gov: NCT02961426 and the National Medical Research Register of Malaysia NMRR-16-747-29183. Findings: Between October 2016 and June 2017, 301 subjects were enrolled and 300 included in the full analysis set: 97 with GT1a, 27 GT1b, 2 GT2, 158 GT3, and 16 GT6; 81 (27%) had compensated cirrhosis; 90 (30%) had HIV co-infection; and 99 (33%) had prior interferon-based treatment. 291/300 subjects (97%, 95% CI 94%-99%) achieved SVR12. Three subjects prematurely discontinued study treatment due to adverse events. There were no deaths or treatment discontinuations due to the study drugs. Interpretation: In this first stage, ravidasvir plus sofosbuvir was found to be highly effective and well tolerated in all subgroups of this diverse adult population chronically infected with HCV. Trial Registration Number: This trial is registered with ClinicalTrials.gov: NCT02961426 and the National Medical Research Register of Malaysia NMRR-16-747-29183. Funding: Drugs for Neglected Diseases initiative; National Science and Technology Development Agency, Thailand; Department of Disease Control, Ministry of Public Health, Thailand; Ministry of Health, Malaysia. Conflict of Interest: Dr. Avihingsanon reports grants from National Science and Technology Development Agency (NSTDA) during the conduct of the study, and also from ViiV Healthcare outside of thesubmitted work. Tim Cressey and Nicolas Salvadori report a service agreement with DNDi.Isabelle Andrieux-Meyer, Caroline Menetrey, Francois Simon, Jean-Michel Piedagnel,Sasikala Siva, Alistair Swanson, Francois Bompart, Vishal Goyal, and Bernard Pecoul are employed by the Drugs for Neglected Diseases initiative. All other authors do not report any potential conflicts of interest. Ethical Approval: The initial protocol and all protocol amendments were reviewed and approved before implementation by the applicable individual institutional or national ethics committees. All subjects provided written informed consent.