PGx7667 (207389) Exploratory Pharmacogenetic Investigation of Efficacy Response to mepolizumab in Eosinophilic Granulomatosis Polyangiitis (Churg-Strauss Syndrome) PGstudy 115921

Trial description: Mepolizumab obtained orphan drug status for treatment of eosinophilic granulomatosis polyangiitis (EGPA) in the US in July 2011 and February 2013 in the EU. Genetic samples are not available from the previous studies and MEA115921, the pivotal Phase 3 study, provides the first opportunity to assess the impact of genetic variation on response to mepolizumab in patients with EGPA. These pharmacogenetic analyses were designed to assess if genetic variation influences response to mepolizumab using data from MEA115921 with the following co-primary endpoints: accrued duration of remission, average oral corticosteroid (OCS) dose during last 4 weeks, and frequency of EGPA relapse. Genetic variation from across the genome and pre-specified candidate gene variants were assessed using linear regression (for the remission and OCS dose endpoints) and negative binomial regression (for the frequency of relapse endpoint).