By Amin Rostami-Hodjegan, Pharm.D., Ph.D., Centre for Applied Pharmacokinetic Research (CAPKR), University of Manchester, and Certara; Adam Darwich, Ph.D., CAPKR; Ellen Leinfuss, Certara
While the use of physiologically based pharmacokinetic (PBPK) modeling and simulation (M&S) in drug development was first proposed in 1937 by Torsten Teorell, the applications were mainly confined to environmental science and the fields of animal or human toxicology until the 21st century.1 It is only in the past five years that its impact has reached the point where it is actively encouraged by global regulators and increasingly leveraged by biopharmaceutical companies. It is now well accepted that throughout a drug’s life cycle, PBPK can be used to support decisions on whether, when, and how to conduct certain clinical pharmacology studies and to support dosing recommendations for product labeling. It is used to support strategic decision-making, providing valuable information regarding clinical trial design, and it can be used to help obtain clinical trial waivers. Most important, PBPK helps answer a myriad of “what if” questions that could not be answered without lengthy, expensive, logistically challenging, and sometimes ethically questionable clinical studies. So what caused such a shift between the end of the 20th century and today, when PBPK is considered an industrial necessity?