Abstract

The discovery of leptin in 1994 was a seminal event in obesity research. It helped to establish that body weight is tightly regulated by a complex neurohormonal feedback system and that obesity should be viewed as a disorder with a strong biological basis rather than simply the result of poor lifestyle choices and lack of willpower.

Leptin, secreted from adipocytes, acts as a prototypic long-term (tonic) adiposity signal. Although nonclinical and clinical studies have provided unequivocal evidence that leptin plays a unique, pivotal role in body weight regulation, efforts to develop recombinant leptin (metreleptin) as a monotherapy for obesity have proven unsuccessful. Amylin, secreted from pancreatic β-cells, fulfills the criteria for a short-term (episodic) satiety signal. The amylin analog pramlintide elicits sustained reductions in food intake and body weight in obese rodents and humans.

A translational research program aimed at elucidating the interaction between different islet-, gut-, and adipocyte-derived hormones led to the discovery that combined amylin/leptin agonism induces marked, synergistic, fat-specific weight loss in leptin-resistant diet-induced obese rodents. In obese humans, combination treatment with pramlintide/metreleptin led to an approximately 13% weight loss after 24 weeks, significantly more than after treatment with pramlintide or metreleptin alone.

Collectively, these findings suggest that combined amylin/leptin agonism may have therapeutic utility as part of an integrated, neurohormonal approach to obesity pharmacotherapy.