Introduction and Objective: Survodutide, a dual glucagon/GLP-1 receptor agonist in phase 3 trials for obesity and metabolic dysfunction-associated steatohepatitis, contains a C18-diacid half-life extension (HLE) group for once weekly dosing. This study thoroughly investigated the in vitro receptor pharmacology of survodutide and the impact of its HLE using time-resolved cellular assays. Methods: GCGR and GLP-1R both signal via an increase in intracellular cAMP levels upon agonist activation. Survodutide and its analogue without the HLE were assessed for binding and cAMP signaling at GCGR and GLP-1R, with and without human serum albumin (HSA). Binding affinities were measured using Tag-Lite technology, while time-resolved cAMP responses, β-arrestin recruitment as a measure of cAMP desensitization, and receptor internalization were quantified using biosensors and imaging. Data were analyzed using non-linear regression. Results: Survodutide elicited equipotent cAMP responses of 2-3 pM for GLP-1R and GCGR versus endogenous ligands. In contrast, in the presence of 0.1% HSA, EC50 values increased from 3 pM to 750 pM for GCGR and from 3 pM to 90 pM for GLP-1R and confirmed survodutide’s 8-fold higher potency on GLP-1R over GCGR. The potency shift observed in the presence of HSA was mediated by the HLE, as evidenced by the analogue lacking HLE, which maintained unchanged potencies under HSA across multiple assay formats. While for GLP-1R both survodutide and its analogue without HLE showed a maximal cAMP response consistent with native GLP-1, at GCGR, survodutide demonstrated biased agonism with reduced β-arrestin recruitment (54%) and receptor internalization (81%) compared to endogenous glucagon, suggesting lower receptor desensitization and prolonged GCGR effects. Conclusion: Survodutide, in time-resolved cellular systems, exhibits a differentiated pharmacological profile at GLP-1R and GCGR, with biased agonism at GCGR potentially contributing to sustained therapeutic effects. Disclosure B. Berger: Employee; Current; Boehringer Ingelheim International GmbH. M. Schuler: Employee; Current; Boehringer Ingelheim International GmbH. P. Haebel: Employee; Current; Boehringer Ingelheim International GmbH. T. Klein: Employee; Current; Boehringer Ingelheim International GmbH. R. Augustin: Employee; Current; Boehringer Ingelheim International GmbH. Funding Boehringer Ingelheim
BERGER et al. (Sat,) studied this question.