Development of PRS-400, an inhaled Jagged-1 Anticalin protein for the treatment of muco-obstructive lung diseases

Abstract

<b>Background:</b> Anticalin^® proteins derived from human lipocalins can be engineered to bind to their targets with high potency and selectivity and are well-suited for inhaled delivery with the potential for a higher therapeutic index. The Jagged-1/Notch pathway is a promising therapeutic target given preclinical data reflecting its role in goblet cell metaplasia and mucus obstruction that are pathogenic features of many chronic airway diseases. <b>Objective:</b> To develop a Jagged-1-binding Anticalin protein for the treatment of muco-obstructive lung diseases via an inhaled delivery. <b>Methods:</b> Display selection technology was used for candidate identification. Binding characteristics and <i>in vitro</i> potency of Jagged-1-targeting Anticalin proteins were determined. Anticalin proteins were screened for their ability to interact with the mucus layer. The impact of Jagged-1-binding Anticalin proteins was assessed in primary human bronchial epithelial cell (HBEC) air-liquid-interface (ALI) cultures. <b>Results:</b> We identified Anticalin proteins binding with high affinity and specificity to different epitopes of Jagged-1. Further, a dose-dependent inhibition of Jagged-1-Notch2 interaction was observed. Jagged-1-targeting Anticalin proteins reduced secretory- and increased ciliated cell marker expression in <i>ex vivo</i> HBEC ALI cultures and showed little or no interaction with mucus to ensure target engagement. <b>Conclusions:</b> We report the identification of novel and potent Jagged-1-targeting Anticalin proteins. The data support further development of PRS-400 as a potential inhaled therapy for patients with muco-obstructive respiratory diseases.