GCG and obesity due to melanocortin 4 receptor deficiency: Among the reasons behind the development of new chemical entities (NCEs) in the polypeptide segment there is the commercial and therapeutic success of GLP-1 analogues, Liraglutide and Semaglutide, for the treatment of type 2 diabetes and obesity, that exceeded 7.6 B$ sales in 2020 (Novo Nordisk 2020 annual report, February 3, 2021).