A Novel Inhalable Nanobody Targeting IL-4Rα for the Treatment of Asthma.

ABSTRACT

BACKGROUND: Inhalable biologics represent a promising approach to improve the efficacy and safety of asthma treatment. Although several monoclonal antibodies (mAbs) targeting IL-4Rα have been approved or are undergoing clinical trials, the development of inhalable mAbs targeting IL-4Rα presents significant challenges. OBJECTIVE: Capitalizing on the distinctive advantages of nanobodies (Nbs) in maintaining efficacy during storage and administration, we sought to develop a novel inhalable IL-4Rα Nb for effectively treating asthma. METHODS: Three IL-4Rα immunized Nb libraries were utilized to generate specific and functional IL-4Rα Nbs. LQ036, a bivalent Nb comprising two HuNb103 units, was constructed with a high affinity and specificity for hIL-4Rα. The efficacy, pharmacokinetic and safety of inhaled LQ036 were evaluated in B-hIL4/hIL4Ra humanized mice. RESULTS: LQ036 inhibited secreted embryonic alkaline phosphatase (SEAP) reporter activity, TF-1 cell proliferation, and suppressed pSTAT6 in T cells from asthma patients. Crystal structure analysis revealed a binding region similar to Dupilumab but with higher affinity, leading to better efficacy in blocking the signaling pathway. HuNb103 competed with IL-4 and IL-13 for IL-4Rα binding. Additionally, LQ036 significantly inhibited OVA-specific IgE levels in serum, CCL17 levels in BALF, bronchial mucous cell hyperplasia, and airway goblet cell hyperplasia in B-hIL4/hIL4Ra humanized mice. Inhaled LQ036 exhibited favorable pharmacokinetics, safety and tissue distribution, with higher concentrations observed in the lungs and bronchi. CONCLUSION: These findings from preclinical studies establish the safety and efficacy of inhaled LQ036, underscoring its potential as a pioneering inhalable biologic therapy for asthma.