Concordance between SVR4 and SVR24 in DAA Based Regimens: A real life experience including post-liver transplant patients

BACKGROUND AND AIM: The use of direct antiviral (DAA) regimens for the treatment of chronic HCV infection is associated with high rates of sustained virological response (SVR), independently from HCV genotype, stage of liver disease, baseline viral load and response to previous therapies. Shortening the follow up period after the end of therapy, considering SVR4 equivalent to SVR12-24 could have implications in accelerating drug development and trial reporting. We aimed at assessing concordance between SVR4 and SVR 12-24 in chronic HCV patients who received antiviral treatment with DAAs in Interferon (IFN) containing or IFN free regimens. METHODS: Between January 2012 and February 2015, 300 HCV patients, followed at our Center, received treatment. SVR4, 12, 24 was defined as HCV RNA target not detected by the Abbott RT-PCR (LOD 12 IU/mL) at week 4, 12 or 24 following treatment cessation. RESULTS: 199 patients (66%), 31 (67%) post liver transplant (LT), completed the follow-up period of 24 weeks and were assessed in the current analysis. The median followup period was of 18 months (range 6-37 months). Baseline and demographics characteristics are shown in Table 1. In the post-LT group end of treatment response rate (ETR) was 100% (31/31), 29 (95%) had SVR4 and 28 (90%) had SVR12 and SVR24. The one late viral relapse was observed in a patient treated with an IFN containing regimen. No relapses after week 4 of follow-up were seen in IFN free treatments. In the immunocompetent group of 168, 130 achieved ETR (130/168, 77%), 112 (67%) SVR4 and 108 (64%) SVR 12 and 24. All four patients with a virological relapse after week 4 of follow-up received an IFN containing regimen. No relapse after week 4 of follow-up was observed in IFN free regimens. Overall, concordance between SVR4 and SVR24 was 100% in IFN free and 96% in IFN containing regimens. CONCLUSIONS: In IFN free regimens SVR-4 by the Abbott RT-PCR assay can be considered as viral cure of HCV in immunocompetent and immunocompromised patients. (Figure Presented).