Leonhard holds a B. Sc. & M. Sc. in Pharmaceutical Science from the Ludwig Maximilian University as well as a B. Sc. in Management and Technology from the Technical University Munich. In 2022, he joined the group of Prof. Reinhold Penner at the Queen’s Center for Biomedical Research to investigate the effects of cannabinoids, specifically cannabigerolic acid (CBGA), cannabicyclol (CBL), and cannabinodiol (CBND), on the transient receptor potential ankyrin 1 (TRPA1) channel, a key player in pain perception. For his master’s thesis, he investigated therapeutic strategies for frontotemporal dementia (FTD) associated with GRN gene mutations. His work, conducted in the lab of Dr. Lorea Blazquez at the BioGipuzkoa Health Research Institute, focused on exon skipping techniques using antisense oligonucleotides and CRISPR-Cas13d.

In April 2025, Leonhard began his PhD studies in the Biopharmacy Group, where he is now researching P-glycoprotein with the aim of advancing personalized medicine by understanding how individual variability in P-gp activity affects therapeutic outcomes.