How to Design an Inhaled Drug: CHF-6523.

Inhalation provides an opportunity to target drugs to the lung, potentially improving efficacy and safety margins for the treatment of respiratory conditions. The discovery of inhaled medicines is a specialized endeavor and has different challenges to medicinal chemistry for oral drugs. The appearance of a successful campaign delivering an inhaled PI3Kδ inhibitor is therefore an opportunity to highlight how a team can address the challenges involved in the identification of such a compound. This Viewpoint seeks to highlight a great example of medicinal chemistry in the inhaled space.