LY-104

LY-104 is a **small-molecule investigational drug candidate** being developed in China for **chronic obstructive pulmonary disease**. Publicly available sources identify it as a **structurally novel PDE4B inhibitor** discovered from a marine natural-product-inspired program associated with Ocean University of China and Qingdao marine-biomedicine groups. Preclinical descriptions indicate a multimodal anti-COPD profile, with reported bronchodilatory, anti-inflammatory, and tissue-metabolism or repair-related effects, but the clearly attributable primary mechanism in public drug databases is **phosphodiesterase 4B inhibition**. As of publicly reported 2025-2026 sources, LY-104 injection had received clinical trial authorization in China and appears to be in **Phase 1 / IND-approved clinical development** for COPD.