QST and the Transformation in Drug Safety Assessment

Paul B. Watkins, M.D. FAASLD
Director, Institute for Drug Safety Sciences , University of North Carolina in 
Chapel Hill

Wednesday December 16, 2020, 12:00 to 1:00 pm EDT

Register for free at https://www.rosaandco.com/webinars

Abstract:
Establishing the safety of new drug candidates is a major hurdle to drug 
development as standard preclinical toxicology does not reliably predict human 
adverse drug events. Liver toxicity is a potentially fatal adverse event that 
has been particularly challenging to predict from preclinical studies. 
Moreover, abnormalities in serum liver chemistries are commonly observed in 
clinical trials raising suspicion of liver safety liability that can currently 
only be removed with very large clinical trials. This talk will focus on the 
progress of a public-private partnership (the DILI-sim Initiative) that for the 
last decade has been developing a Quantitative Systems Toxicology (QST) model 
(DILIsym(r)) to improve mechanistic understanding and therefore prediction of 
liver safety liabilities of new drug candidates.

The DILIsym model uses PBPK and other available data to determine the 
concentration of parent drug and major metabolites inside the hepatocyte during 
various dosing regimens. Also fed into the model are the exposure dependent 
effects of parent drug and major metabolites on oxidative stress, bile acid 
homeostasis, and mitochondrial function as measured in in vitro or cellular 
systems. Parameters in the model have been varied to reflect genetic and 
non-genetic variability to create a virtual healthy human population as well as 
disease-specific populations. With the data inputs, DILIsym will predict the 
incidence and severity of liver injury that will be observed in a simulated 
patient population as a function of dosing regimen. Results of DILIsym modeling 
are increasingly used in decision making within Pharma and have also been 
helpful in interactions with regulators.

DILIsym provides an example of how increased application of QST modeling should 
transform the safety assessment of new drug candidates as well as risk 
management in clinical trials and post-approval.


Reply via email to