COST-EFFECTIVENESS ANALYSIS OF DRUGS FOR CHRONIC HEPATITIS C INFECTION: INFORMING ON LISTING DECISIONS OF INTERFERON-FREE DIRECT-ACTING ANTIVIRAL REGIMENS IN CANADA

Purpose:   Prior to 2011, pegylated interferon plus ribavirin (PR) was the standard therapy for chronic hepatitis C (CHC).  Since 2014, a number of interferon-free direct-acting antiviral agents (DAAs) have been approved.  While these treatments appear to be more effective at achieving sustained virologic response in CHC patients, they are significantly more expensive than PR. In anticipation of the need for information regarding the comparative cost-effectiveness of new regimens, we updated a previous cost-effectiveness analysis used to inform listing decisions in Canada by including recently approved and emerging regimens for the treatment of CHC infection (genotypes 1 through 4).

Method:   A state-transition model was developed in the form of a cost-utility analysis. Regimens included in the analysis were approved in Canada, recommended by major guidelines, or considered to have a high likelihood of approval in Canada as of February 2015. The cohort under consideration had a mean age of 50 years and was defined by treatment status (naive versus experienced), and cirrhosis status (non-cirrhotic versus cirrhotic). Treatment effect estimates for sustained virologic response (SVR) and relative risk of adverse events were obtained from a concurrent network meta-analysis. Other inputs for the economic model were derived from published sources and validated by clinical experts. Drug costs were obtained from the Canadian provincial formularies, or directly from manufacturers.

Result:   For each genotype 1 population at least one of the interferon-free therapies (e.g. Harvoni, Holkira Pak) appeared to be economically attractive compared with PR alone, at a willingness-to-pay of $50,000 per Quality-adjusted-life-year (QALY). The regimen that was the most cost-effective varied by population. For each genotype 2-4 treatment naive population, the interferon-free or the PR-based DAA therapies appeared not to be economically attractive compared with PR alone, at a willingness-to-pay of $50,000/QALY. For each genotype 2-4 treatment-experienced population, there were interferon-free or the PR-based DAA therapies that appeared to be attractive at a willingness to pay of $50,000/QALY when compared with no treatment.

Conclusion:   Public health policy should be informed by consideration of health benefit, social and ethical values, feasibility, and cost-effectiveness.  Our analysis assists the development of HCV reimbursement recommendations by informing the latter criterion.  Considering the rapid pace of development of treatments for CHC, updated and expanded reviews will be necessary in the future.