Dr. J.J. (Jesse) Swen


  • Ziekenhuisapotheker
  • Associate Professor of Pharmacogenetics
  • Klinisch farmacoloog
  • Hoofd Sectie Laboratorium


Jesse Swen PharmD, PhD is an associate professor of pharmacogenetics and clinical pharmacist-clinical pharmacologist at the Department of Clinical Pharmacy & Toxicology, Leiden University Medical Center. He is the chair of the laboratory of the hospital pharmacy. 

The long-term central goal of my career is to improve the outcomes of drug treatment by gaining a better understanding of the genetic mechanisms that result in inter-individual variability in drug response. Our limited ability to predict drug pharmacokinetics, response, and toxicity presents a significant challenge that needs to be resolved. I aim to gain novel mechanistic insights into the origins of this limited ability by working on the following research questions:

- Dissecting the impact of rare, structural and regulatory variants on drug absorption, distribution, metabolism, and excretion (ADME) 

- Elucidating the mismatch between the drug metabolizer genotype and the capacity of an individual to metabolize drugs (Phenoconversion).

- Translating pharmacogenomics to patient care.

This work is seamlessly integrated with his work as chair of the pharmacy laboratory.

I have (co-)authored more than 100 (Web of Science indexed) articles in international peer reviewed scientific journals and several chapters in books. I’m one of the primary investigators of the “Ubiquitous Pharmacogenomics” project (www.upgx.eu). U-PGx aims to implement pharmacogenetics across 7 European sites by genotyping 8,100 patients. In addition I am an active member of the Dutch Pharmacogenetics Working Group and the US Clinical Pharmacogenetics Implementation Consortium.  

Key publications

Swen JJ, Nijenhuis M, de Boer A, Grandia L, Maitland-van der Zee AH, Mulder H, Rongen GA, van Schaik RH, Schalekamp T, Touw DJ, van der Weide J, Wilffert B, Deneer VH, Guchelaar HJ. Pharmacogenetics: from bench to byte--an update of guidelines. Clinical pharmacology and therapeutics 2011;89:662-73. Foundational work explaining the work of the Dutch Pharmacogenetics Working group on developing PGx guidelines that help clinicians to use PGx test results to guide drug prescribing and dispensing. 

Swen JJ, Nijenhuis M, van Rhenen M, de Boer-Veger NJ, Buunk AM, Houwink EJF, Mulder H, Rongen GA, van Schaik RHN, van der Weide J, Wilffert B, Deneer VHM, Guchelaar HJ. Pharmacogenetic Information in Clinical Guidelines: The European Perspective. Clinical pharmacology and therapeutics 2018;103:795-801. Key paper describing how I envision PGx will change drug prescribing and dispensing in the next decade.

van der Lee M, Allard WG, Bollen S, Santen GWE, Ruivenkamp CAL, Hoffer MJV, Kriek M, Guchelaar HJ, Anvar SY, Swen JJ. Repurposing of Diagnostic Whole Exome Sequencing Data of 1,583 Individuals for Clinical Pharmacogenetics. Clin Pharmacol Ther 2020;107:617-27. This work is the basis for expanding the number of patients with a pharmacogenetics profile. Based on the results, similar approaches may be used by other medical centers (ongoing in Amsterdam UMC).

Van der Lee M, Allard WG, Vossen R, Baak-Pablo RF, Menafra R, Deiman B, Deenen MJ, Neven P, Johansson I, Gastaldello S, Ingelman-Sundberg M, Guchelaar HJ, Swen JJ, Anvar SY. Toward predicting CYP2D6-mediated variable drug response from CYP2D6 gene sequencing data. Sci Transl Med 2021;13. In this paper we show that by combining long-read sequencing with a neural network model and the use of a continuous instead of categorical scale, we are able to substantially improve our ability to explain the interindividual variability in CYP2D6 activity from 39% to 79%.

Klomp SD, Manson ML, Guchelaar HJ, Swen JJ. Phenoconversion of Cytochrome P450 Metabolism: A Systematic Review. J Clin Med 2020;9. In this paper we review the mechanisms of phenoconversion of Cytochrome P450.



Leids Universitair Medisch Centrum
Gebouw 1
Kamer L-01-019

Albinusdreef 2
2333 ZA Leiden
Tel: 071 526 6125

Postzone L0-P
Postbus 9600
2300 RC Leiden

E-mail: j.j.swen@lumc.nl