Cost-effectiveness of nirmatrelvir/ritonavir in COVID-19 patient groups at high risk for progression to severe COVID-19 in the Netherlands

Abstract

Background: Nirmatrelvir/ritonavir is indicated for the treatment of COVID-19 in symptomatic adults with increased risk for severe illness, not requiring supplemental oxygen yet. From a Dutch societal perspective, a cost-utility assessment of nirmatrelvir/ritonavir versus best supportive care (BSC) was conducted in three patient groups: (a) immunocompromised patients, (b) patients aged at least 60 years with one comorbidity, (c) patients aged at least 70 years. Groups were selected considering their relevance as high-risk groups, as described in Dutch and international guidelines and recommendations. Methods: A one-year decision-tree, estimating costs and outcomes associated with a COVID-19 infection was coupled to a lifetime two-state Markov component simulating subsequent life-time survival and quality of life. Effectiveness estimates, informing the intervention preventing hospital admission or death, were based on real-world evidence by Lewnard and colleagues (2023) in a vaccinated population during a timeframe with predominance of the Omicron variant. Epidemiology relies on publicly available data, primarily sourced during the Omicron variant’s era. In the decision tree, clinically relevant event-related disutilities per disease course were applied to adjusted age-dependent Dutch-specific utility levels. In the Markov component, a disutility was considered for post-ICU patients. Costs rely on Dutch pharmacoeconomic guidelines and public data sources. The incremental cost-effectiveness ratio (ICER) was analysed as the main outcome, with a positive ICER indicating the cost associated with each additional quality-adjusted life year (QALY) gained by adopting the intervention. Results: Nirmatrelvir/ritonavir was associated with an ICER of € 395 in the immunocompromised group (per patient: + 0.125 QALYs gained; + 0.130 life-years [LYs] gained; € 49 incremental cost), with an ICER of € 8700 in 60-plus patients with comorbidity (+ 0.054 QALYs; + 0.055 LYs; € 474 incremental cost), and with an ICER of € 13,021 among 70-plus patients (+ 0.053 QALYs; + 0.045 LYs; € 689 incremental cost). Results were most sensitive to the baseline hospitalization rates among high-risk individuals. Probabilistic sensitivity analyses indicate a high probability of being cost-effective (100, 94, 85% respectively), considering a willingness-to-pay threshold of € 20,000 per QALY. Conclusions: From a Dutch societal perspective, over a lifetime horizon, nirmatrelvir/ritonavir is cost-effective versus BSC in the three groups analysed.