Abstract
BACKGROUND: Despite the success of current treatments, many chronic hepatitis B (CHB) patients still live with low-level viremia [LLV] resulting in liver disease progression. This study evaluated the long-term health and economic impact of switching to tenofovir alafenamide (TAF) from entecavir (ETV) in Saudi Arabia (SA) in chronic hepatitis B (CHB) LLV patients. METHODS: A hybrid decision tree Markov state-transition model was developed to simulate a cohort of patients with CHB LLV treated with ETV and switched to TAF over a lifetime horizon in SA. While on treatment, patients either achieved complete virologic response (CVR) or maintained LLV. CVR patients experienced slower progression to advanced liver disease stages as compared to LLV patients. Demographic data, transition probabilities, treatment efficacy, health state costs, and utilities were sourced from published literature. Treatment costs were sourced from publicly available databases. RESULTS: Base case analysis found that over a lifetime horizon, switching to TAF versus remaining on ETV increased the proportion of patients achieving CVR (76% versus 14%, respectively). Switching to TAF versus remaining on ETV resulted in a reduction in cases of compensated cirrhosis (-52%), decompensated cirrhosis (-5%), hepatocellular carcinoma (-22%), liver transplants (-12%), and a 37% reduction in liver-related deaths. Switching to TAF was cost-effective with an incremental cost-effectiveness ratio of $57,222, assuming a willingness-to-pay threshold of three times gross national income per capita [$65,790/QALY]. CONCLUSIONS: This model found that switching to TAF versus remaining on ETV in SA CHB LLV patients substantially reduced long-term CHB-related morbidity and mortality and was a cost-effective treatment strategy.