Microphysiological systems in early stage drug development: Perspectives on current applications and future impact.

Microphysiological systems (MPS) are making advances to provide more standardized and predictive physiologically relevant responses to test articles in living tissues and organ systems. The excitement surrounding the potential of MPS to better predict human responses to medicines and improving clinical translation is overshadowed by their relatively slow adoption by the pharmaceutical industry and regulators. Collaboration between multiorganizational consortia and regulators is necessary to build an understanding of the strengths and limitations of MPS models and closing the current gaps. Here, we review some of the advances in MPS research, focusing on liver, intestine, vascular system, kidney and lung and present examples highlighting the context of use for these systems. For MPS to gain a foothold in drug development, they must have added value over existing approaches. Ideally, the application of MPS will augment in vivo studies and reduce the use of animals via tiered screening with less reliance on exploratory toxicology studies to screen compounds. Because MPS support multiple cell types (e.g. primary or stem-cell derived cells) and organ systems, identifying when MPS are more appropriate than simple 2D in vitro models for understanding physiological responses to test articles is necessary. Once identified, MPS models require qualification for that specific context of use and must be reproducible to allow future validation. Ultimately, the challenges of balancing complexity with reproducibility will inform the promise of advancing the MPS field and are critical for realization of the goal to reduce, refine and replace (3Rs) the use of animals in nonclinical research.

Is Science the Only Driver in Species Selection? An Internal Study to Evaluate Compound Requirements in the Minipig Compared to the Dog in Preclinical Studies.

Dogs have been often chosen as a nonrodent species for preclinical development of small molecule drugs mainly due to availability and relative ease of handling. Recently, focus has increased on the minipig as a potential alternative to the dog, based on either scientific rationale or public opinion concerns. There are, however, other factors influencing nonrodent choices, in particular drug amount and synthesis time, which differ between species and therefore may impact the milestones of a drug development program. To assess the magnitude of compound need, a retrospective internal survey was conducted on drug amounts used in dog studies which were translated into the requirements for minipigs. Compound need approximately doubles if minipigs are used. Costs of compound are accordingly higher, and synthesis times are slightly increased. In our company, the differences were not considered significant enough to preclude the use of minipigs if the later preclinical program might benefit from improved human risk prediction.

Practical aspects of discovery pathology.

Pathologists are uniquely qualified to play a central role in driving drug discovery and development programs by: 1) establishing disease models to assess potential therapies, 2) characterizing modifications in the disease state in response to therapies, 3) characterizing toxicologic mechanisms and responses to drug candidates, and 4) facilitating multidisciplinary efforts to monitor for the clinical occurrence, progression, and reversibility of adverse events. Such nontraditional deployment of resources must, to be viable, produce benefits to the pharmaceutical industry comparable to those of more conventional activities such as delivery of data in nonclinical safety studies. Additionally, benefits must be tangible from standpoints such as time savings or improved quality of research decisions, manifesting as either program acceleration or improved candidate survival.