# Predictive Value of Sustained Virologic Response at Week 4 in Patients with Hepatitis C Virus Infection Treated with Sofosbuvir/Velpatasvir

## TL;DR

This study shows that checking for a hepatitis C cure at week 4 instead of week 12 after treatment is reliable and could help patients stay in care.

## Contribution

The study demonstrates that SVR4 is a valid predictor of SVR12 in patients treated with SOF/VEL, supporting earlier cure confirmation.

## Key findings

- In clinical trials, 99.7% of patients who achieved SVR4 also achieved SVR12.
- In real-world data, 94% of patients achieved SVR4 and 95% achieved SVR12, with high concordance between the two.
- Shifting cure confirmation to week 4 could reduce patient loss to follow-up.

## Abstract

Direct-acting antiviral therapies can cure most people with hepatitis C virus (HCV) infection with little need for testing or monitoring. A major challenge to eliminating HCV is ensuring patients complete all steps of care, including confirmation of cure. We assessed the concordance of sustained virologic response (SVR) at 4 weeks (SVR4) and 12 weeks (SVR12) post-treatment to evaluate the viability of SVR4 as a predictor of cure in patients treated with sofosbuvir (SOF)/velpatasvir (VEL). We conducted a retrospective analysis of patients from the Phase 3 ASTRAL-1, -2, and -3 programs and a historical cohort from the Louisiana Department of Health Sexually Transmitted Infection (STI)/HIV/Hepatitis Program claims database. Concordance analyses were performed for patients with both SVR4 and SVR12 data. The concordance analysis in the ASTRAL studies included 1015 patients; 1005 and 1002 achieved SVR4 and SVR12, respectively. Among SVR4 achievers, 3 failed to maintain SVR12, while all (10/10) patients who did not achieve SVR4 also failed SVR12. In the real-world cohort, 479/509 (94%) patients achieved SVR4 and 485/509 (95%) achieved SVR12. Of those with SVR4, 7 failed SVR12; 17 of 30 patients who did not achieve SVR4 also failed SVR12. High concordance between SVR4 and SVR12 was observed in both ASTRAL and the real-world dataset, supporting the use of SVR4 as a predictor of long-term SVR in patients with HCV infection treated with SOF/VEL. Streamlining cure confirmation by shifting SVR determination from week 12 to week 4 post-treatment may reduce patient loss to follow-up.