"Given the size of the T2D market I find it very odd how few of these targets are being explored by big pharma."
This is not true. Most of the targets big pharma working on are at very early stage (Discovery stage). I know for sure that more than 15 different targets are being worked on currently.
Some of them are: CCR2 antagonists, GDIR (or GPR119) agonists, GPR120, GPR140, peripheral CB1, etc,.
The probelm with these targets are, they show very good potency and efficacy in preclinical species, but in clinic they are all duds.
One target, GCGR is very potent and efficacious, but issues with elevated liver enzymes since it is directly working on liver.
