Insulin, like growth factor receptor-1 (IGF-1R) is well characterized in cancer and there are lots of clinical agents in preclinical development phase, but still there is no drug or no clinical agent in phase III. Why?
Maybe, I think its structural analogue, insulin, conserve the same signalling as IGF-1R has. But as insulin is metabolic more active, so it may cause a problem to the researcher. Here below I am attaching a link related to this concern.
https://www.researchgate.net/publication/235393946_Recent_Advancements_in_Small_Molecule_Inhibitors_of_Insulin-like_Growth_Factor-1_Receptor_(IGF-1R)_Tyrosine_Kinase_as_Anticancer_agents
Whereas I still don't know the reason.
Article Recent Advancements in Small Molecule Inhibitors of Insulin–...