The major research focus is in using pharmacokinetic/pharmacodynamic modelling to answer questions such as: Does drug X affect disease process Y?  If so, what dose should we recommend?  Often these questions are most challenging when patients are children, and since maturation is a continuous not dichotomous process, understanding appropriate scaling for size and age is important.   Mechanistic, biologically plausible models are fitted using non-linear mixed effects, sometimes using 'priors'. 

Current projects include: Modelling HIV viral load and CD4 counts in adults and children, and investigating the role of antiretroviral treatment on long-term viral suppression and immune reconstitution; Pharmacokinetic/pharmacodynamic studies of antimicrobial and antiviral agents in pre-term and term neonates; Models for immune reconstitution following bone marrow transplantation in children and personalised pre-transplant conditioning; Investigating novel treatments for Polycystic Kidney Disease using pharmacokinetic/pharmacodynamic modelling; Pharmacokinetic/pharmacodynamic modelling to support antimicrobial stewardship.

The London Pharmacometrics Interest Group holds weekly meetings to discuss this kind of research, more information can be found here: 
https://wiki.ucl.ac.uk/display/~ucbpjle/London+Pharmacometrics+Interest+Group