ESPE Abstracts

With the rising prevalence of childhood obesity, there has been an increase in the number of children presenting with severe obesity. Whilst only a relatively small proportion of severely obese children will have the classical features associated with the well-established genetic obesity syndromes such as Prader-Willi syndrome, there is increasing recognition that highly penetrant genetic disorders can frequently present as severe obesity alone without developmental delay, dys...

Introduction: Hypothalamic obesity (HyOb) is a rare form of treatment-resistant morbid obesity associated with congenital or acquired hypothalamic damage. Its pathophysiology is incompletely understood, with weight gain being attributed to hyperphagia and hyperinsulinaemia. We sought to compare the physiology of various plasma appetite-regulating hormones in HyOb and ‘simple’ obesity (Ob) to improve our understanding of both forms of obesity and identify novel therap...

Background: Congenital leptin deficiency (CLD) is characterized by severe early-onset obesity due to hyperphagia and impaired satiety. The impact of obesity in obstructive sleep apnoea hypopnoea syndrome (OSAHS) was originally reported as mechanical, but recent data suggest that adipokines may influence central ventilation. We highlight that treatment with recombinant human leptin (RHL) in CLD with OSAHS improves ventilation before weight loss.Case prese...

Background: Disruption of the melanocortin-4 receptor pathway by genetic variants in POMC/PCSK1 or LEPR can result in hyperphagia and severe early-onset obesity. In the primary analyses of 2 pivotal Phase 3 trials, the melanocortin-4 receptor agonist setmelanotide was associated with significant reductions in body weight and hunger in patients with obesity due to proopiomelanocortin (POMC) or leptin receptor (LEPR) deficiency. These ...

Background: Rare genetic causes of obesity include variants in genes within the melanocortin-4 receptor (MC4R) pathway, a principal regulator of energy balance. Weight and hunger reductions following treatment with the MC4R agonist setmelanotide have been demonstrated in patients with obesity due to variants in multiple genes, including POMC, LEPR, SRC1, and SH2B1. We describe a trial design of setmelanotide in patients with addition...

Background: Variants in SH2B1 or a 220–kilobase pair distal deletion of chromosome 16p11.2, including SH2B1, are associated with severe, early-onset obesity and hyperphagia. The melanocortin-4 receptor (MC4R) agonist setmelanotide is being investigated in individuals with rare variants in genes in the MC4R pathway.Methods: This ongoing, Phase 2 study (NCT03013543) enrolled individuals aged ≥6...

Background: Rare genetic diseases of obesity are often driven by gene variants in the melanocortin-4 receptor (MC4R) pathway. The MC4R agonist setmelanotide demonstrated significant reductions in body weight in patients ≥6 years old with various rare genetic diseases of obesity, including proopiomelanocortin (POMC), proprotein convertase subtilisin/kexin type 1 (PCSK1), or leptin receptor (LEPR) deficiency and Bardet-Biedl syndrome (BBS). While these condit...

Background: Early-onset severe obesity due to leptin deficiency typically results from a defect of leptin production or secretion due to mutations in the leptin gene. Recently we described a new form of leptin deficiency caused by bioinactivity of the hormone and associated with high circulating leptin levels (New England Journal of Medicine 2015 372 48–54).Method: Serum leptin was measured by ELISA. The leptin gene was seq...

Background: Rare genetic diseases of obesity can be caused by genetic variants leading to disrupted activity of the melanocortin-4 receptor pathway (MC4R). Setmelanotide, an MC4R agonist, is being investigated in a basket study of populations with rare variants in different genes in the MC4R pathway who have early-onset, severe obesity and hyperphagia.Methods: This ongoing, Phase 2, open-label study (NCT03013543) enrolle...

Background: The melanocortin-4 receptor (MC4R) pathway is a key regulator of energy balance and satiety. Variants in genes upstream of MC4R encoding leptin receptor (LEPR), proopiomelanocortin (POMC), proprotein convertase subtilisin/kexin type 1(PCSK1) and those involved in Bardet-Biedl syndrome (BBS) can impair MC4R pathway signaling. Clinically, these variants are characterized by hyperphagia (Pathologic insatiable hunger) and early-onset, severe obesity. E...