Petrelintide

Identity a synthetic, long-acting analog of amylin — the hormone co-secreted with insulin by pancreatic beta cells after eating — engineered for once-weekly subcutaneous dosing. A defining design feature: it's chemically and physically stable with no fibrillation around neutral pH, which (unlike native amylin) lets it be co-formulated and co-administered with other peptides — a deliberate "combination-ready" design. Developed by Zealand Pharma, partnered with Roche (2025). ## Mechanism (as proposed) amylin is a hormone co-secreted with insulin by pancreatic beta cells in response to food. Acting at amylin receptors (in the hindbrain/area postrema), it promotes satiety — and, importantly, it restores sensitivity to leptin, the fat-derived "fullness" hormone that obesity tends to blunt (leptin resistance). Petrelintide is a long-acting amylin analog that sustains this signalling with once-weekly dosing, so people feel full faster and eat less. Because this is a different pathway from GLP-1/GIP incretins, amylins are seen as complementary — hence the combination strategy (petrelintide + CT-388). The engineering achievement is stability without fibrillation at neutral pH (native amylin is amyloidogenic — the same problem that shaped Pramlintide's design), which both enables weekly dosing and makes petrelintide co-formulable with other peptides.