Cagrilintide: Long-Acting Amylin Analogue for Metabolic Research

Cagrilintide (AM833) is a long-acting acylated analogue of human amylin developed by Novo Nordisk. Amylin (islet amyloid polypeptide, IAPP) is a peptide co-secreted with insulin from pancreatic β-cells that plays complementary roles to insulin in postprandial glucose regulation. Cagrilintide achieves once-weekly dosing through fatty acid acylation for albumin binding — analogous to the technology used in semaglutide — and is currently in Phase III trials in combination with semaglutide as CagriSema for obesity treatment.

Amylin Biology

Amylin is co-released with insulin in a 1:100 molar ratio from pancreatic β-cells in response to meals. It acts on amylin receptors (calcitonin receptor + RAMP1/2/3 co-proteins) in the area postrema, hypothalamus, and brainstem to exert complementary glycaemic effects:

• Gastric emptying slowing: Reduces the rate of nutrient delivery to the small intestine, blunting postprandial glucose excursions
• Glucagon suppression: Inhibits meal-stimulated glucagon secretion from α-cells, reducing hepatic glucose output
• Satiety signalling: Acts in the hypothalamus to reduce food intake and promote satiety

In type 2 diabetes and obesity, amylin signalling is deficient (β-cell amylin secretion is reduced) or disrupted (IAPP aggregation and β-cell toxicity). Pramlintide (Symlin), a first-generation amylin analogue, was FDA-approved in 2005 for type 1 and type 2 diabetes but required three-times-daily injection — a major compliance limitation that cagrilintide's weekly dosing addresses.

Cagrilintide Pharmacology

Cagrilintide's C18 fatty diacid modification enables albumin binding analogous to semaglutide, extending half-life to approximately 7-8 days. Phase I data (Gall et al., 2020, Diabetes, Obesity and Metabolism) demonstrated dose-dependent body weight reduction of up to 8.0% over 26 weeks at 4.5 mg/week, with dose-dependent nausea as the primary adverse effect — consistent with amylin receptor activation in the area postrema.

CagriSema Combination Research

The combination of cagrilintide with semaglutide (GLP-1 receptor agonist) in the CagriSema programme represents a mechanistically rational dual hormone strategy targeting complementary satiety pathways:

• GLP-1 (semaglutide): Acts on GLP-1R in hypothalamus, brainstem, and vagus to reduce appetite and slow gastric emptying via distinct CNS pathways from amylin
• Amylin (cagrilintide): Acts on amylin receptors in area postrema and hypothalamus for complementary satiety signalling, glucagon suppression, and additional gastric emptying regulation

Phase II SCALE data showed CagriSema produced weight loss of approximately 15.6% over 32 weeks at full doses — exceeding either agent alone and consistent with additive or synergistic satiety mechanisms. Phase III REDEFINE trials are ongoing and represent the leading edge of obesity pharmacotherapy research.

Lean Mass Preservation Research

A critical research question for obesity treatments is the ratio of fat mass to lean mass loss. Preliminary data suggests amylin-based approaches may preferentially preserve lean mass compared to GLP-1-only approaches — potentially due to amylin receptor expression in muscle and distinct energy substrate selection signalling. Research comparing body composition changes between amylin analogue, GLP-1 RA, and combination strategies is ongoing.