A phase 2 study of SelK2 on sputum cell counts in COPD

<bold>Background:</bold> Airway inflammation is a hallmark of COPD. This process involves PSGL-1/selectin binding between circulating inflammatory cells and the endothelium facilitating transmigration of cells into the lung. SelK2 is a monoclonal antibody to PSGL-1 that blocks cell recruitment into inflamed tissues. <bold>Methods:</bold> This phase 2, randomized, double-blind, placebo-controlled parallel group study (EudraCT: 2020-001027-13) evaluated the safety and efficacy of IV-administered SelK2 in COPD (17 SelK2:8 placebo). Subjects required a sputum neutrophil differential count of >55% at screening and received a single dose of 7.5 mg/kg SelK2 or placebo. Sputum induction and differential cell counts were performed at screening and post-dose, with day 21 being a key analysis timepoint. <bold>Results:</bold> SelK2 significantly reduced total cell count per gram of sputum compared to placebo from screening to day 21 (p= 0.026). Importantly, there were significant reductions in absolute neutrophil and eosinophil cell counts in sputum (Table 1) but not in blood. There were no treatment differences for sputum percentage cell counts most likely due to the marked reduction in absolute counts of different cell types. There were no changes in FEV1 across treatment groups in this short study. There were no safety signals of concern. <bold>Conclusion:</bold> A single SelK2 dose significantly reduced absolute sputum neutrophils and eosinophils in COPD consistent with decreased migration from the blood. This study indicates potential for SelK2 as an anti-inflammatory COPD treatment. Table 1: <table-wrap><object-id>erj;64/suppl_68/OA3646/TB1</object-id><object-id>T1</object-id><object-id>TB1</object-id><table><colgroup><col></col><col></col><col></col><col></col></colgroup><tbody><tr><td>Mean Sputum cells (x10⁶/g)</td><td> SelK2 (N=17) </td><td> Placebo (N=8) </td><td><italic>p</italic>-value</td></tr><tr><td>Screen</td><td>Day 21</td><td>Screen</td><td>Day 21</td></tr><tr><td>Neutrophils</td><td>4.1</td><td>1.7</td><td>5.8</td><td>5.8</td><td>0.041</td></tr><tr><td>Eosinophils</td><td>0.10</td><td>0.02</td><td>0.17</td><td>0.23</td><td>0.018</td></tr></tbody></table></table-wrap>