SC19

SC19 is a potent and selective peptide agonist of the melanocortin-4 receptor (MC4R), developed as an optimized derivative of setmelanotide. It was engineered to overcome the limitations of setmelanotide, specifically its low aqueous solubility and off-target effects like hyperpigmentation caused by MC1R activation. SC19 incorporates a C-terminal lysine to enhance solubility and modifications to the core pharmacophore to achieve high selectivity (>100-fold) over MC1R and MC3R. In preclinical diet-induced obesity models, SC19 demonstrated significant efficacy in reducing weight gain and improving lipid profiles, comparable to setmelanotide but with a more favorable pharmacological profile.