Real-life experience on efficacy and safety of setmelanotide treatment in prepubertal children.

Monogenic obesity, characterized by severe, early-onset obesity due to single-gene defects, often resists traditional weight management strategies. This report presents real-life experiences on the efficacy and safety of setmelanotide, an MC4R agonist, in 4 prepubertal children (ages 3-9) with LEPR and POMC deficiencies. Findings indicate that setmelanotide is effective at lower doses in our patients with POMC deficiency (0.3-0.5 mg/day) than the patients with LEPR deficiency (2.5 mg/day). Treatment was generally well-tolerated, with injection site reactions and hyperpigmentation as common side effects. As novel findings, gonadotropin-related effects such as hypothalamo-pituitary-gonadal axis activation and testicular descent were observed in 2 patients. Growth deceleration was noted in 2 children, and recovery from central hypothyroidism in 1 patient with POMC deficiency. Overall, setmelanotide appears to be effective and well-tolerated in young children with monogenic obesity. However, further studies are necessary to evaluate the long-term effects of early intervention on growth and pubertal development.