Cagrilintide

Overview

Cagrilintide represents a mechanistically distinct approach to weight loss pharmaceuticals. While the field has been dominated by GLP-1 receptor agonists since exenatide's approval in 2005, cagrilintide targets amylin receptors — an entirely different satiety pathway — enabling true additive or synergistic effects when combined with GLP-1 agents.

Developed by Novo Nordisk, cagrilintide is designed as a once-weekly amylin/CGRP receptor co-agonist. Its parent molecule, amylin, is a 37-amino acid peptide co-secreted with insulin from pancreatic beta cells. Native amylin has poor pharmaceutical properties (short half-life, aggregation tendency) — cagrilintide's modifications solve these issues.

Mechanism

Amylin Receptor Biology

Amylin receptors are heterodimers of the calcitonin receptor (CTR) paired with receptor activity-modifying proteins (RAMP1, 2, or 3). Cagrilintide activates:

• AMY1 receptor (CTR + RAMP1): Primary target; highest in brainstem
• AMY3 receptor (CTR + RAMP3): Secondary target
• CGRP receptors: Partial activity — contributes to peripheral vasodilation

Central Satiety Actions

1. Area postrema activation: Brainstem satiety center directly accessible from bloodstream; reduces meal size
2. Hypothalamic effects: Modulates arcuate nucleus circuits (NPY/AgRP inhibition, POMC activation)
3. Gastric emptying reduction: Slows glucose absorption, attenuating post-meal glucose spikes
4. Glucagon suppression: Reduces post-meal glucagon, contributing to glycemic control

Why CagriSema Works Better Than Either Alone

The key insight: amylin and GLP-1 satiety pathways are anatomically and mechanistically distinct. GLP-1 receptors are dense in the vagus nerve and nucleus tractus solitarius; amylin receptors are concentrated in the area postrema and hypothalamus. Combining them addresses multiple satiety circuits simultaneously without dose-limiting GI effects from stacking two GLP-1 agonists.

CagriSema Clinical Data

| Treatment | Weight loss at 32 weeks | |-----------|------------------------| | Placebo | ~2% | | Cagrilintide 2.4mg | ~11% | | Semaglutide 2.4mg | ~15% | | CagriSema (both) | ~25% |

This additive effect is precisely what the amylin/GLP-1 combination hypothesis predicted — and distinguishes CagriSema from simple GLP-1 dose escalation.