Cost-Effectiveness of Tenofovir Alafenamide for Treatment of Chronic Hepatitis B in Canada

Abstract

Background/Aim: Tenofovir alafenamide (TAF) has been approved for treating chronic hepatitis B (CHB) due to a proposed better safety profile in comparison with current therapies. We evaluated the cost effectiveness of TAF and other available treatment options for hepatitis B envelope antigen (HBeAg)-positive and HBeAg-negative CHB patients from a Canadian provincial Ministry of Health perspective. Methods: A state-transition model based on the published literature was developed to compare treatment strategies involving entecavir (ETV), tenofovir disoproxil fumarate (TDF), and TAF. It adopted a lifetime time horizon. Outcomes measured were predicted number of liver-related deaths, costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios (ICERs). Results: For HBeAg-positive patients, TAF followed by ETV generated an additional 0.16 QALYs/person at an additional cost of Can$14,836.18 with an ICER of Can$94,142.71/QALY compared with TDF followed by ETV. Of the iterations, 28.7% showed that it is the optimal strategy with a Can$50,000 willingness-to-pay threshold. For HBeAg-negative patients, ETV followed by TAF would prevent an additional 13 liver-related deaths per 1000 CHB patients compared with TDF, followed by ETV. It generated an additional 0.13 QALYs/person at an additional cost of Can$59,776.53 with an ICER of Can$461,162.21/QALY compared with TDF, followed by ETV. TAF-containing strategies are unlikely to be a rational choice in either case. The results were sensitive to the HBeAg seroconversion rates and viral suppression rates of the treatments. Conclusions: Our analysis suggests that TAF is not cost effective at its current cost. A 33.4% reduction in price would be required to make it cost effective for HBeAg-positive patients with a Can$50,000 willingness-to-pay threshold.