FDA Breakthrough status for Rhythm's setmelanotide

The Food and Drug Administration has expanded a previously granted Breakthrough Therapy designation (BTD) for setmelanotide, a novel melanocortin-4 receptor (MC4R) agonist from Boston, USA-based biotech firm Rhythm Pharmaceuticals.

The expanded BTD is for the treatment of obesity associated with genetic defects upstream of the MC4 receptor in the leptin-melanocortin pathway (the MC4 pathway), which includes both pro-opiomelanocortin (POMC) and leptin receptor (LepR) deficiency obesity. The FDA had previously granted BTD to setmelanotide for the treatment of POMC deficiency obesity.

Rhythm is developing setmelanotide for the treatment of obesity caused by genetic deficiencies in the MC4 pathway, a key biological pathway in humans that regulates weight by increasing energy expenditure and reducing appetite. The company has completed positive Phase II clinical trials in both POMC deficiency obesity and LepR deficiency obesity in which patients treated with setmelanotide experienced significant weight loss and substantial reductions in hunger. Setmelanotide was well tolerated in these trials. Rhythm recently initiated a Phase III clinical trial of setmelanotide in POMC deficiency obesity.