The goal of this study is to assess hepatitis C virus (HCV) treatment with Zepatier (elbasvir/grazoprevir) in HCV monoinfected and human immunodeficiency virus (HIV)-HCV co-infected, HCV treatment-naïve or peginterferon/ribavirin-experienced patients with HCV genotype 1a, without baseline NS5A resistance, 1b, or 4 and substance use in urban, multidisciplinary specialty clinics.

Previously, people who use substances and those without liver fibrosis or cirrhosis were excluded from receiving direct-acting antiviral (DAA) treatment due to Illinois Medicaid restrictions. These sobriety and staging restrictions were recently lifted. However, due to these previous stringent requirements for sobriety, many patients were not able to be treated for HCV. This created a data gap for real-world outcomes of HCV treatment in people who use substances. This study presents a unique opportunity to provide patients with hepatitis C treatment and obtain much needed data on the use of elbasvir/grazoprevir in patients with substance use and other underrepresented comorbidities. Additionally, this study will determine if our current standard of care for the treatment of HCV is effective for patients with substance use.

Inclusion Criteria:

• Adults (at least 18 years of age or older)
• Chronic HCV (HCV antibody positive with detectable HCV-RNA)
• HCV genotypes 1a, without the presence of baseline NS5A resistance (specifically, polymorphisms at amino acid positions 28, 30, 31, or 93), 1b, or 4
• HCV treatment-naïve or peginterferon/ribavirin-experienced
• Managed by the UI Health Infectious Diseases Clinic or Liver Clinic
• Recent or current substance use (per self-report or electronic medical record (EMR) data within 90 days of the screening visit, with or without positive baseline urine toxicology), inclusive of one or more of the following: Opiate substitution therapy; Prescription medication misuse (including: opiates, sedatives, tranquilizers, hypnotics, and psychostimulants); Illicit substances; Injection drug use; Alcohol

Exclusion Criteria:

• Incarcerated
• Pregnant or breastfeeding
• Decompensated liver disease (Child-Pugh B or C)
• Albumin below 3 g/dL
• Platelet count below 75,000
• Unwilling to commit to treatment and/or monitoring
• Poor venous access inhibiting laboratory collection
• Any condition considered by the investigators to be a contraindication to study participation
• Hepatitis B virus (HBV) surface antigen (HBsAg) positive

The specific patient population to be studied is HCV monoinfected and HIV-HCV co-infected, HCV treatment-naïve or peginterferon/ribavirin-experienced patients of the UI Health Infectious Disease or Liver Clinic with HCV genotype 1a, without baseline NS5A resistance, 1b, or 4 and substance use treated with 12 weeks of elbasvir/grazoprevir therapy.