Microphysiological lung models to evaluate the safety of new pharmaceutical modalities: a biopharmaceutical perspective.

The lung is a complex organ; it is both the initial barrier for inhaled agents and the site of metabolism and therapeutic effect for a subset of systemically administered drugs. Comprised of more than 40 cell types that are responsible for various important functions, the lung's complexity contributes to the subsequent challenges in developing complex in vitro co-culture models (also called microphysiological systems (MPS), complex in vitro models or organs-on-a-chip). Although there are multiple considerations and limitations in the development and qualification of such in vitro systems, MPS exhibit great promise in the fields of pharmacology and toxicology. Successful development and implementation of MPS models may enable mechanistic bridging between non-clinical species and humans, and increase clinical relevance of safety endpoints, while decreasing overall animal use. This article summarizes, from a biopharmaceutical industry perspective, essential elements for the development and qualification of lung MPS models. Its purpose is to guide MPS developers and manufacturers to expedite MPS utilization for safety assessment in the biopharmaceutical industry.