Selection of BI 456906 as a Dual GCGR/GLP-1R Agonist Based on In Vitro Potency and In Vivo Target Engagement Biomarkers

Glucagon (GCG) and glucagon-like peptide 1 (GLP-1) are peptide hormones that pharmacologically regulate bodyweight by increasing energy expenditure and reducing energy intake, respectively. Several dual (GCG receptor [GCGR]/GLP-1 receptor [GLP-1R]) agonistic peptides are in clinical development for obesity. We describe preclinical data leading to selection of BI 456906 as a dual agonist. Functional potencies of the compounds were determined in CHO-K1 cells stably expressing human GCGR and GLP-1R. EC50 for GCGR mediated cAMP increase were 0.52 nM for BI 456906, 0.92 nM for BI 456908 and 0.44 nM for BI 456987. EC50 for GLP-1R engagement were 0.33 nM, 0.61 nM and 1.43 nM, respectively. Upon acute, single dosing to lean mice, engagement of the GCGR and GLP-1R was determined by testing for improvement in oral glucose tolerance (30 nmol/kg) and increase in plasma FGF-21 and liver nicotinamide N-methyltransferase mRNA expression (100 nmol/kg), respectively. Specificity of the biomarkers was confirmed using the selective GLP-1R agonist semaglutide and GLP-1R knockout mice. Bodyweight and glucose lowering (HbA1c) efficacies were investigated in subchronic dosing studies in diet-induced obese (DIO) and diabetic (db/db) mice, respectively. In DIO mice, BI 456906 (30 nmol/kg qd), BI 456908 (30 nmol/kg qd) and BI 456897 (10 nmol/kg qd) achieved bodyweight lowering from baseline of 25%, 27%, and 26%, respectively. In db/db mice, BI 456906 and BI 456908 (10 and 20 nmol/kg qd) substantially lowered HbA1c (0.4-0.6%); no clear effect was observed for BI 456897 (3 and 7 nmol/kg qd). As a balanced GCGR/GLP-1R agonist with robust in vivo efficacy BI 456906 (30 nmol/kg qd) was further characterized, and superior bodyweight lowering (32% vs 27%; p<0.05) was seen versus a maximally effective semaglutide dose (100 nmol/kg qd). This was attributed to an increase in energy expenditure. The selected candidate, BI 456906, is currently in clinical development in people with obesity and NASH. Disclosure R.Augustin: None. L.Thomas: Employee; Boehringer Ingelheim Pharma GmbH&Co.KG. T.Zimmermann: Employee; Boehringer Ingelheim Pharma GmbH&Co.KG. E.Simon: Employee; Boehringer Ingelheim Pharma GmbH&Co.KG. W.Rist: None. I.Uphues: Employee; Boehringer Ingelheim Pharma GmbH&Co.KG. W.Reindl: None. T.Klein: Employee; Boehringer Ingelheim Pharma GmbH&Co.KG. H.Neubauer: None. Funding Zealand Pharma A/S; Boehringer Ingelheim