Background: European guidelines advocate the measurement of on-treatment hepatitis C virus (HCV) RNA in order to determine optimal therapy duration (response-guided therapy [RGT]) in patients with rapid virological response (RVR) or delayed virological response (DVR). Treatment response is highly dependent upon the extent of liver fibrosis yet there is little evidence quantifying the cost effectiveness of RGT particularly conditional upon fibrosis stage.
Objective: This study describes an economic model designed to assess the costs and benefits of RGT compared with standard duration of therapy (SDT) in hepatitis C virus genotype 1 patients.
Methods: A Markov cohort simulation model with lifetime perspective was developed to undertake a cost utility analysis of RGT in the UK. Patients entered the model at Metavir disease stages F0-F4, and progressed through these stages via age and duration of HCV infection-dependent transition probabilities. Treated patients were partitioned according to virological response and shortened or extended duration of therapy was applied following European guidelines.
Results: For all patients, SDT and RGT was associated with an increase of 2.14 and 2.20 QALYs and £2,374 and £2,270 costs, respectively, compared with no treatment. Overall, RGT was a dominant scenario being associated with a lower risk of complications, increased QALYs (0.08) and cost saving (£101). RGT across fibrosis stages was either highly cost effective or dominant; in all cases RGT was associated with an increase in QALYs, driven by a reduction in complications in DVR subjects and reduced exposure to treatment disutility in RVR subjects; costs were lower in F1 and F2 fibrosis stages. At a willingness-to-pay threshold of £20,000 per QALY, overall RGT across fibrosis stages F2-F4 were associated with the highest probability of being cost effective. At this threshold, the probability of reduced/extended therapy in RVR/DVR patients being cost effective is 0.35 and 0.88, respectively.
Conclusions: This analysis suggests that the treatment of HCV genotype 1 patients in fibrosis stage F2 has the greatest potential for maximizing health benefit and cost saving within an RGT protocol. Predicting those patients most likely to respond to treatments is important from both a clinical and cost perspective and the tailoring of treatment duration with the current standard of care is likely to remain a priority for payers with budgetary constraints.