Hepatitis C direct-acting antiviral treatment selection, treatment failure, and use of drug-drug interactions in a state Medicaid program

Abstract

BACKGROUND: Newer hepatitis C virus (HCV) treatments often provide high success rates with fewer adverse events, although the extent of all potential drug interactions is not fully known. OBJECTIVE: To assess outcomes of receiving HCV treatment and subsequent sustained virologic response (SVR) based on patient and clinical characteristics, including direct-acting antiviral (DAA) drug-drug interactions (DDIs), in Medicaid members with chronic HCV. METHODS: Comprehensive medical and pharmacy claims and prior authorization data were collected for HCV patients requesting treatment between January 2014 and June 2015. Outcomes of receiving treatment with DAAs and treatment failure based on SVR were analyzed according to demographics, prior/current HCV treatment, severity of DDIs, advancing liver disease, and comorbidities. Multivariable generalized linear models were employed, including a Bayesian sensitivity analysis. RESULTS: Among 3,412 Medicaid members with HCV, 13.6% received DAAs (n=464), averaging 53.6±10.0 years, with 52.8% female. Multivariable analyses indicated that higher odds of DAA treatment initiation were associated with older age, prior HCV treatment, and advancing liver disease. Some 4.8% of treatment failures occurred among 168 patients with reported SVRs, wherein a 3.218 times higher adjusted odds of treatment failure was associated with concomitant use of medications with DDIs classified as significant or potentially clinically significant by the University of Liverpool HEP Drug Interactions resource (P=0.001). CONCLUSIONS: In a cohort of state Medicaid members with chronic HCV, a markedly higher adjusted odds of treatment failure was independently associated with DDIs classified as significant or potentially clinically significant, warranting continued inquiry and potential alternate treatments concerning conditions that require their use.