A phase 1 RCT in which adults with common obesity or overweight together with low baseline leptin levels (<5 ng/mL) were treated with mibavademab, demonstrated a placebo-subtracted weight loss of -2.8 kg (-3.1%) and -2.4 kg (-3.1%) in a phase 1 RCT. The gene discussed is LEP; the disease is obesity due to melanocortin 4 receptor deficiency.