AstraZeneca agreed to license Sino Biopharmaceutical’s investigational dual PDE3/4 inhibitor TQC3721 for ex-China rights in a deal worth up to $2.1 billion. Sino’s subsidiary Chia Tai Tianqing Pharmaceutical will grant AstraZeneca exclusive global rights outside China, with milestone payments and royalties tied to development and sales. The asset targets chronic obstructive pulmonary disease (COPD) and is positioned as a challenger to Merck’s Ohtuvayre (ensifentrine), which established the PDE3/4 class reference point after Verona Pharma’s acquisition by Merck. TQC3721 is in phase III in China for a nebulized formulation and in phase II for a dry powder inhaler. The licensing reinforces AstraZeneca’s respiratory strategy and further intensifies competitive dynamics in COPD as multiple PDE3/4 programs advance.