PRS28 THE COST-EFFECTIVENESS OF IL-5 INHIBITORS FOR PERSONS WITH EOSINOPHILIC ASTHMA

Abstract

The study assessed the cost-effectiveness of IL-5 inhibitors (mepolizumab, reslizumab, and benralizumab) vs. standard of care (SoC) in patients with severe eosinophilic asthma. A Markov model with a payer perspective was used to compare the costs and quality-adjusted life years (QALYs) of IL-5 inhibitors versus SoC alone. The model adopted a cycle length of two weeks with three primary health states over a lifetime horizon (5 years): an asthma non-exacerbation state, asthma exacerbation state (three subcategories: asthma-related event requiring OCS burst; asthma-related emergency department visit; or asthma-related hospitalization), and death. The population was adult patients (≥12 years) with severe eosinophilic asthma (eosinophils ≥300 cells/μL) based on the Global Initiative for Asthma (GINA) steps 4/5 who had experienced at least three exacerbations in the preceding year. Model inputs were obtained from individual patient-level data from two 52-week randomized controlled trials of reslizumab (NCT01287039/ NCT01285323), 32-week RCT of mepolizumab (NCT01691521), and two identical RCTs for benralizumab (NCT01928771/ NCT01914757). Drug costs were based on REDBOOK WAC. Cost and utility values were obtained from previous mepolizumab ICER review. The outcome of interest was incremental cost-effectiveness ratio (ICER), expressed as cost per QALYs gained using 3% discount rate and 2018 currency value. Both deterministic and probabilistic sensitivity analyses were performed. Treatment with mepolizumab, benralizumab, reslizumab were all associated with increased cost of ($493,302.14), ($534,914.29), ($590,851.60), respectively as compared with SoC. These therapies were associated with improved QALYs of 2.81, 2.90, 2.87 respectively, compared with SoC alone, resulting ICER values of $175,271, $184,158, $205,538 per QALY gained, respectively for mepolizumab, benralizumab, and reslizumab. For patients with high eosinophilic asthma, treatment with IL-5 inhibitors as compared to SoC was found to have ICER values that exceed $150,000/QALY. However, these treatments resulted in substantial QALY gains over a fairly limited time horizon.