Infectious Disease
Hepatitis C RNA blood serum results at treatment completion predict sustained virologic response in a cohort of people who use drugs Claire C McDonell* Claire McDonell Meghan D Morris Jennifer C Price Ryan D Assaf Jeff McKinney
Sustained virologic response at 12-weeks post-treatment completion (SVR12) is considered the gold standard clinical efficacy endpoint for direct acting antiviral (DAA) hepatitis C (HCV) treatment. However, its origin dates back to interferon therapy which required close clinical observation and had cure rates closer to 60%, compared to DAA’s 90-95%. While serology from the SVR12 timepoint consistently predicts cure in both cases, it also requires patients to return for bloodwork three months after they complete treatment. This may contribute to loss to follow up, especially for those who often face instability in their life, such as people who inject drugs. To explore shortening this gap, we assessed concordance between the presence of HCV RNA in serum samples at treatment completion, 4-weeks post-treatment (SVR4), and SVR12 “cure” by calculating positive predictive values (PPV) and negative predictive values (NPV). Clinical data was used from a single arm trial (NCT03987503) of participants who received a standard course of the DAA sofosbuvir/velpatasvir. Of the eighty-seven (N=87) participants who initiated treatment, 97% had an income below the national poverty line, 80% had recently injected drugs, and 43% were experiencing homelessness. Sixty-nine (79%) completed treatment and 58 (67%) attained SVR12. Six participants were lost to follow-up between treatment completion and SVR12. Both the PPV and NPV of SVR4 for SVR12 were 100%. The PPV and NPV of treatment completion for SVR12 was 100% and 97%, respectively. Those with discordance (n=2) had different genotypes pre- and post-treatment, likely indicating new (re)infection. Among this cohort, virologic response at treatment completion and SVR4 closely predicted SVR12. Additionally, fewer participants were lost to follow-up at these earlier timepoints. DAA clinical trial data should be analyzed to assess if earlier timepoints consistently predict HCV cure outside of this socially marginalized cohort.