Depemokimab PK/PD in the 52-week randomised double-blind multicentre Phase III SWIFT-1 trial

<bold>Background:</bold> Depemokimab is the first and only humanised anti-IL-5 antibody with enhanced binding affinity and high potency, resulting in extended half-life and enabling 6-monthly dosing. <bold>Aim:</bold> Investigate depemokimab pharmacokinetic (PK)/pharmacodynamic (PD) durability in patients with asthma in SWIFT-1. <bold>Methods:</bold> Study design is described in Fig. 1. Blood eosinophil counts (BEC) were log_e transformed; ratio to baseline was analysed with a mixed model for repeated measures. <bold>Results:</bold> Depemokimab plasma concentrations and BEC are shown in Fig. 2. Baseline geometric mean BEC was 298 cells/μl (SD logs 0.80) for depemokimab (N=250) and 310 cells/μl (SD logs 0.84) for placebo (N=132). Week 2 depemokimab BEC ratio to baseline was ~5-fold lower vs placebo (0.20 vs 1.07; ratio 0.19 [95% CI 0.16, 0.21; p<0.001]). This ~5-fold BEC suppression was sustained to Week 52 (depemokimab 0.17 vs 0.81; ratio 0.21 [95% CI 0.17, 0.26; p<0.001]). <bold>Conclusions:</bold> Sustained depemokimab concentration and rapid and sustained BEC suppression, reflecting inflammation biomarkers, support depemokimab as a twice-yearly option for patients with asthma. <bold>Funding:</bold> GSK 206713; <ext-link>NCT04719832</ext-link>. <fig><object-id>erj;64/suppl_68/OA3647/F1</object-id><object-id>F1</object-id><object-id>F1</object-id><graphic></graphic></fig> <fig><object-id>erj;64/suppl_68/OA3647/F2</object-id><object-id>F2</object-id><object-id>F2</object-id><graphic></graphic></fig>