Cagrilintide

Cagrilintide 10mg is a long-acting amylin analog peptide supplied in lyophilized form for in vitro and preclinical research applications. With ≥99% purity confirmed by HPLC and mass spectrometry, this vial format is intended strictly for laboratory use and is not approved, intended, or suitable for human or veterinary administration.

What Is Cagrilintide?

Cagrilintide (also designated AM833) is a fatty-acid acylated analog of human amylin engineered by Novo Nordisk to exhibit substantially prolonged duration of action compared to native amylin or its earlier analog pramlintide. Amylin is a 37-amino acid pancreatic peptide co-secreted with insulin from beta cells in response to nutrient ingestion. While insulin manages peripheral glucose disposal, amylin simultaneously acts in the central nervous system and gastrointestinal tract to slow gastric emptying, suppress post-prandial glucagon secretion, and signal satiety — functions that work in concert with insulin to regulate postprandial glycemia.

The structure of cagrilintide incorporates strategic amino acid substitutions that reduce aggregation tendency (a limitation of native amylin), plus a fatty acid chain that facilitates albumin binding, extending plasma half-life to approximately seven days in human pharmacokinetic studies. This once-weekly dosing profile makes cagrilintide mechanistically compatible with once-weekly GLP-1 receptor agonists such as semaglutide, enabling the combination product "CagriSema" studied in the SCALE-STEP clinical program.

Mechanism of Action

Cagrilintide exerts its effects primarily through agonism at amylin receptors, which are heterodimeric complexes formed by the calcitonin receptor (CTR) subunit paired with receptor activity-modifying proteins (RAMPs), particularly RAMP1 (forming AMY1), RAMP2 (AMY2), and RAMP3 (AMY3). These receptor complexes are expressed in the area postrema, nucleus tractus solitarius (NTS), and the hypothalamic arcuate nucleus — brain regions that integrate peripheral satiety signals.

Key pharmacological actions observed in preclinical research models include:

**Gastric Emptying Delay:** Amylin receptor signaling in the dorsal vagal complex significantly slows the rate at which stomach contents empty into the duodenum. This dampening of gastric transit reduces the rate of post-meal glucose appearance in circulation and prolongs the satiety signal generated by gastric distension.

**Glucagon Suppression:** Following a meal, inappropriate glucagon secretion from pancreatic alpha cells contributes to postprandial hyperglycemia. Cagrilintide, like native amylin, suppresses glucagon secretion in a glucose-dependent manner, providing an additional layer of glycemic regulation beyond what insulin alone achieves.

**Central Appetite Modulation:** In rodent studies, amylin receptor agonism in the area postrema reduces food intake through pathways that converge on hypothalamic satiety circuits. Unlike leptin, amylin/cagrilintide does not appear to face the receptor downregulation that characterizes diet-induced obesity, making it a sustained appetite-suppressant signal even in obese animals.

**Body Composition Effects:** Rodent obesity models treated with amylin or cagrilintide analogs show preferential loss of fat mass over lean mass, a distinction that has important implications for metabolic health beyond simple weight reduction.

**Complementary GLP-1 Synergy:** When cagrilintide is combined with GLP-1R agonists in preclinical studies, researchers observe additive to synergistic reductions in food intake and body weight beyond what either agent achieves alone. The mechanistic basis appears to involve complementary receptor populations and signaling pathways: GLP-1R agonists primarily act on vagal afferents and hypothalamic neurons expressing GLP-1R, while amylin receptors are enriched in distinct (though overlapping) brainstem and hypothalamic regions. The combination effectively engages multiple satiety circuits simultaneously.

Receptor Pharmacology

Cagrilintide's acylation with a C18 fatty diacid linked through a hydrophilic spacer to a lysine residue at position 25 enables reversible binding to serum albumin. When dissociated from albumin, free cagrilintide binds amylin receptor complexes with high affinity. Ki values for human AMY1, AMY2, and AMY3 receptors have been characterized in vitro, confirming engagement across the amylin receptor family with selectivity over the calcitonin receptor alone (CTR without RAMP), which mediates calcitonin's bone-regulatory effects.

The extended plasma half-life (~7 days in humans) also reduces peak-to-trough fluctuations in receptor occupancy compared to shorter-acting analogs, potentially providing more consistent central and peripheral signaling across the dosing interval — an important pharmacodynamic consideration in chronic administration experiments.

Preclinical Research Applications

Researchers studying cagrilintide in vitro and in animal models have explored several application areas:

**Metabolic Disease Models:** In diet-induced obese (DIO) mouse and rat models, cagrilintide reduces body weight, improves fasting glucose, lowers HbA1c equivalents, and improves insulin sensitivity. These effects are amplified when combined with semaglutide in CagriSema combination protocols, with some DIO mouse studies reporting near-complete normalization of body weight.

**Appetite Circuit Mapping:** In vivo neurophysiology studies and c-Fos activation mapping have used amylin receptor agonists to delineate the circuits mediating appetite suppression, helping identify downstream targets in the NTS-to-hypothalamus axis.

**Adipose Tissue Biology:** Research has examined how amylin receptor signaling influences adipokine secretion, lipolysis rates, and fat depot-specific responses, contributing to understanding of how amylin pathways interact with leptin and insulin signaling in adipose tissue.

**Combination Pharmacology Studies:** Given the clinical development of CagriSema (cagrilintide + semaglutide), preclinical researchers have designed dose-matrix experiments to characterize drug-drug interactions, identify optimal dose ratios, and characterize potential off-target effects at combined exposure levels.

**Bone Metabolism Considerations:** Because the calcitonin receptor shares subunit architecture with amylin receptors, research has examined whether potent amylin receptor agonists with cagrilintide's potency profile produce off-target calcitonin-like effects on bone density or calcium regulation — a consideration for long-term safety assessment in animal models.

Reconstitution and Handling

**Reconstitution Protocol:** Cagrilintide 10mg lyophilized powder is typically reconstituted in bacteriostatic water (0.9% benzyl alcohol) for research use to provide antimicrobial preservation over multiple sampling sessions. Sterile water for injection can also be used for single-use preparations.

Recommended reconstitution approach: 1. Allow the sealed vial to equilibrate to room temperature (approximately 15 minutes) before opening to minimize condensation. 2. Add diluent slowly down the inner wall of the vial rather than directly onto the powder cake, using a sterile syringe and needle under aseptic conditions. 3. Gently swirl the vial — do not vortex or shake — to allow complete dissolution. The reconstituted solution should be clear and colorless. 4. For a 10mg vial, adding 2.0 mL diluent yields a 5 mg/mL (5000 µg/mL) working stock. Adding 10 mL yields a 1 mg/mL stock convenient for subcutaneous dose calculations in rodent studies.

**Storage:** - Lyophilized (unopened): Store at -20°C, protected from light and moisture. Properly stored lyophilized peptide is stable for 24+ months. - Reconstituted solution: Refrigerate at 2–8°C. Bacteriostatic preparations are typically usable for 28 days; sterile water preparations should be used within 72 hours or aliquoted and stored at -80°C to prevent degradation. - Avoid repeated freeze-thaw cycles, which can cause aggregation and activity loss.

Structure and Physicochemical Properties

- **Type:** Acylated amylin analog - **Molecular Weight:** Approximately 4,600 Da (varies by acyl chain and spacer) - **Sequence Basis:** Human amylin (IAPP) with position-specific substitutions to reduce aggregation and a fatty acid acyl chain at Lys25 - **Disulfide Bond:** Cys2–Cys7 (retained from native amylin) - **C-terminal Amidation:** Present (as in native amylin) - **Half-life:** ~7 days (human PK); extended in rodents relative to pramlintide

Regulatory and Safety Information

Cagrilintide is a research compound available exclusively for laboratory investigation. It is not approved by the FDA, EMA, or any regulatory body for clinical or therapeutic use in humans or animals. This material is supplied under the following conditions:

- **Research Use Only (RUO):** For in vitro experiments, cell assays, and properly authorized animal studies conducted by qualified research personnel. - **Not for Human Use:** This compound must not be administered to humans under any circumstances. - **Institutional Compliance:** Use should comply with institutional biosafety committee (IBC) protocols and IACUC approvals for animal research. - **Handling Precautions:** Standard peptide handling precautions apply. Avoid inhalation of powder during reconstitution. Dispose of sharps and biological waste per institutional guidelines. - **No Clinical Claims:** Nothing in this product listing constitutes a claim about human therapeutic efficacy, safety, or applicability.

Related Research Compounds

Researchers investigating amylin receptor pharmacology and metabolic disease mechanisms may also consider:

- **Pramlintide:** An earlier-generation amylin analog (synthetic version of rat amylin) approved in the US as Symlin for diabetes management; shorter half-life (2.5 hours) compared to cagrilintide, useful for studying acute amylin receptor effects. - **Salmon Calcitonin:** A calcitonin receptor agonist that cross-reacts with some amylin receptor complexes; used in mechanistic studies to distinguish AMY- vs CTR-mediated effects. - **Semaglutide / GLP-1 Analogs:** Frequently combined with cagrilintide in preclinical combination studies modeling the clinical CagriSema program. - **Amylin (IAPP):** Native human islet amyloid polypeptide; aggregation-prone but useful as a reference ligand in binding assays. - **NN9278 (Amycretin):** An investigational dual amylin/GLP-1 receptor co-agonist representing the next generation of combined amylin/incretin therapeutic concepts.

All compounds listed above are available for research purposes only and carry the same RUO designation as cagrilintide.