The ability to quantify the capacity of a central nervous system (CNS) drug to cross the human blood-brain barrier (BBB) provides valuable information for de-risking drug development of new molecules. In this study, led by Invicro UK (formerly Imanova), a suitable PET ligand was not available for the evaluation of a potent muscarinic acetylcholine receptor type-1 (M1) allosteric agonist (GSK1034702) in the primate and human brain. Hence, direct radiolabelling of the novel molecule was performed and positron emission tomography (PET) measurements were obtained and combined with in-vitro equilibrium dialysis assays to enable assessment of BBB transport and estimation of the free brain concentration of GSK1034702 in-vivo.
In primate and human PET studies designed to evaluate the transport of a novel M1 allosteric agonist (GSK1034702) across the BBB, Invicro UK demonstrated good brain uptake, and BBB passage consistent with passive diffusion or active influx. These studies discharged some of the perceived development risks for GSK1034702 and provided information to progress the molecule into the next stage of clinical development.