Development of a Suitable Salt Form for a GPR40 Receptor Agonist

AMG 837 (1) is a novel GPR40 agonist selected for clinical development for the treatment of type 2 diabetes. A lysine salt was initially identified as a development form. However, due to the poor crystallinity and severe hygroscopicity of this form, investigations on the free acid form of the drug substance and salt screening were conducted to identify an acceptable physical form for long-term development. A sodium and calcium salt were identified as potentially viable phases, and polymorph screening was conducted on both. The quality attributes of the salts were then compared to determine which phase would be preferred for development.