Samuel Callisto, Ph.D.

Senior Scientist II

Samuel joined MetrumRG in 2019 after earning his PhD in Experimental and Clinical Pharmacology with an emphasis in Pharmacometrics from the University of Minnesota College of Pharmacy. His thesis work focused on modeling cognitive side effects of the anti-epileptic drug topiramate using a combination of pharmacokinetic-pharmacodynamic models and unsupervised machine learning algorithms. While in graduate school he also researched the impact of pharmacogenomics on the pharmacokinetics and pharmacodynamics of multiple drug classes.

Recent publications by this scientist

Pharmacometric Machine Learning: Integrating Neural Networks for Flexible, Advanced Covariate Analysis

June 13, 2025

Presented at ASCPT 2025 Annual Meeting. Neural networks can be integrated with traditional pharmacometric models using several free open-source programming languages. Both Julia and R environments are suitable platforms, but there are tradeoffs regarding development speed, built-in capabilities, and documentation. DCM simplifies the covariate modeling process and uncovers complex, non-linear relationships in computationally efficient workflows.

Download PDF

Reinforcement Learning for Pharmacometrics: A Proof of Concept and Future Directions.

December 6, 2024

Presented at ACoP 2024. A proof-of-concept was conducted using deep reinforcement learning to optimize vancomycin dosing based on predicted PK profiles. The reinforcement learner was able to produce dose recommendations that (on average) exceeded the standard-of-care recommended dose, and future opportunities for using reinforcement learning within pharmacometrics are vast with a large potential for impact through personalized dosing.

Download PDF

Population pharmacokinetic-pharmacodynamic (popPKPD) model of the impact of iclepertin on hemoglobin levels.

July 8, 2024

Presented at PAGE 2024. This model, developed by Boehringer Ingelheim in collaboration with Metrum Research Group, provides insights into potential anemia risks and informs monitoring strategies for patients with cognitive impairment associated with schizophrenia.