Cagrilintide (AM833)

Cagrilintide operates through a neurohormonal mechanism entirely separate from GLP-1 receptor agonists, targeting the amylin receptor family — a group of heterodimeric G-protein coupled receptor complexes formed by the calcitonin receptor (CTR) paired with receptor activity-modifying proteins (RAMP1, RAMP2, or RAMP3) — expressed predominantly in the hypothalamus, brainstem, and peripheral metabolic tissues. Unlike the incretin-based drug class, cagrilintide does not stimulate insulin secretion; instead, it modulates appetite, gastric motility, glucagon secretion, and energy balance through amylin-mediated brain-gut signaling, making its pharmacological profile complementary to — rather than redundant with — GLP-1 agonists.

Amylin Receptor Agonism — Appetite Suppression and Satiety

Amylin, co-secreted with insulin from pancreatic beta cells in response to meals, acts as a satiety signal across the central nervous system and gastrointestinal tract. Cagrilintide mimics and amplifies this effect:

• AMY1R and AMY3R activation in the hypothalamic arcuate nucleus and brainstem area postrema drives satiety signaling, reducing total caloric intake and promoting earlier meal termination — independent of the GLP-1 pathway
• Gastric emptying delay: Cagrilintide slows the rate at which ingested food passes from the stomach into the small intestine, prolonging postprandial fullness and blunting glucose excursions after meals
• Glucagon suppression: Amylin receptor activation inhibits postprandial glucagon secretion from pancreatic alpha cells, contributing to glycemic stability without directly stimulating insulin release
• Hedonic appetite modulation: Amylin receptors are expressed in reward and motivation circuits beyond purely homeostatic brain regions, suggesting cagrilintide may reduce food craving and compulsive eating behavior independent of hunger suppression
• This mechanism explains why cagrilintide shows particular promise for patients who struggle with frequent snacking or binge-type eating patterns, behaviors less well-addressed by GLP-1 receptor agonism alone

Calcitonin Receptor Agonism — The DACRA Distinction

Cagrilintide’s status as a dual amylin/calcitonin receptor co-agonist (DACRA) differentiates it from pramlintide, which binds amylin receptors more selectively:

• The calcitonin receptor (CTR) — the shared structural component of all amylin receptor complexes — is directly activated by cagrilintide, contributing additional weight-reducing pharmacodynamic effects demonstrated to exceed pure amylin agonism in animal models
• Cagrilintide displays an amylin-like binding mode at calcitonin-family receptors but induces distinct conformational dynamics compared to other peptides in the class, including native amylin and salmon calcitonin — a structural property characterized in 2025 cryo-EM studies
• CTR co-activation contributes to bone density modulation — a potentially important consideration given that large-magnitude weight loss drugs generally raise concern about lean mass and skeletal effects
• The differential affinity profile — higher potency at AMY1R and AMY3R than at CTR alone — ensures weight-loss effects are primarily mediated through brain amylin circuits, with CTR engagement providing additive rather than dominant pharmacology

Half-Life Engineering and Pharmacokinetics

Cagrilintide’s once-weekly profile is entirely the product of deliberate structural engineering — native amylin has a biological half-life of only minutes in circulation:

• N-terminal lysine lipidation using a fatty acid chain enables reversible albumin binding, dramatically extending systemic half-life to 159–195 hours (approximately 6.6–8.1 days) and supporting once-weekly subcutaneous administration
• Three amino acid substitutions (N14E, V17R, P37Y) relative to pramlintide alter receptor selectivity to produce the DACRA profile and confer enhanced proteolytic stability
• Proline mutations and structural modifications during development specifically targeted amylin’s well-known propensity to form amyloid fibrils, a formulation and safety challenge that had limited earlier amylin analogue development
• Maximum plasma concentration is achieved at a median of approximately 24 hours after subcutaneous injection; the near-identical pharmacokinetic profile of cagrilintide and semaglutide (half-life ~158 hours) makes dose co-titration of the CagriSema combination clinically manageable without differential peak/trough mismatches
• Cagrilintide is a non-selective AMYR agonist — activating all three amylin receptor subtypes (AMY1R, AMY2R, AMY3R) and the CTR — as opposed to pramlintide, which preferentially engages the human amylin receptor

Complementary Pharmacology with GLP-1 Agonists

The rationale for CagriSema rests on non-overlapping, synergistic mechanisms:

• GLP-1 receptor agonism (semaglutide component) drives glucose-dependent insulin secretion, further appetite suppression, and gastric emptying delay through the incretin axis
• Amylin/calcitonin receptor agonism (cagrilintide component) provides a distinct, additive satiety signal through brain amylin circuits, suppresses glucagon through a complementary pathway, and engages reward-related appetite circuits not fully covered by GLP-1R signaling
• The combination produces superadditive weight loss — the ~22.7% achieved by CagriSema at 68 weeks substantially exceeds the arithmetic sum of each agent’s individual monotherapy efficacy (11.8% cagrilintide + 16.1% semaglutide separately in the same REDEFINE 1 trial)
• This represents a form of “dual-axis neurohormonal metabolic reprogramming” — targeting appetite, satiety, gastric motility, glucagon suppression, and reward-related eating behavior through two independent but physiologically coordinated receptor systems

Cagrilintide has a well-developed clinical evidence base by investigational compound standards, built through Novo Nordisk’s structured Phase 1, Phase 2, and Phase 3 programs. The evidence hierarchy spans in vitro receptor characterization, preclinical animal models, Phase 1b pharmacokinetic and safety studies, Phase 2 randomized controlled trials published in The Lancet, and Phase 3 REDEFINE/REIMAGINE/RENEW trial data. It is important to distinguish cagrilintide monotherapy evidence from CagriSema combination evidence — both are substantial, but the Phase 3 dataset is currently more developed for the combination product.

Preclinical and Structural Evidence

• Animal models demonstrated cagrilintide, as a DACRA, produced greater weight loss than pure amylin agonism, greater than pramlintide, and comparable to or exceeding semaglutide at equivalent dose levels — establishing the pharmacological rationale for human trials
• Cryo-EM structural studies published in Nature Communications in April 2025 characterized cagrilintide’s receptor binding mode, confirming it shares an amylin-like binding geometry at calcitonin-family receptors while inducing distinct receptor conformational dynamics, providing mechanistic insight into its DACRA pharmacological profile
• Development work documented in Journal of Medicinal Chemistry (2021) describes the structure-activity optimization that led to cagrilintide’s selection: dozens of analogues were screened for receptor activity, half-life, and critically for resistance to amyloid fibril formation — the principal formulation barrier that had historically impeded injectable amylin analogue development

Phase 1b Safety and Pharmacokinetic Trials

Enebo et al. (The Lancet, 2021) conducted the pivotal Phase 1b multiple-ascending dose study of cagrilintide co-administered with semaglutide 2.4 mg:

• Enrolled participants were randomized to cagrilintide (0.16–2.4 mg/week) plus semaglutide 2.4 mg/week, or semaglutide 2.4 mg/week plus placebo, over 20 weeks
• The combination achieved −17.1% mean body weight reduction at the 2.4/2.4 mg dose versus −9.5% for semaglutide alone — the first human evidence of synergistic weight loss from cagrilintide/GLP-1 combination
• Pharmacokinetic parameters confirmed cagrilintide half-life of 184 ± 7.4 hours and median Tmax of 24 hours — nearly identical to semaglutide’s profile, validating co-formulation feasibility
• No pharmacokinetic interaction between cagrilintide and semaglutide was detected, confirming independent metabolism and supporting fixed-dose combination development

Phase 2 Obesity Trial — The Lancet (2021)

Lau et al. (The Lancet, 2021) conducted the pivotal Phase 2 dose-finding monotherapy trial:

• 401 adults with overweight or obesity (BMI ≥27 with comorbidity or ≥30) were randomized to once-weekly subcutaneous cagrilintide (0.3–4.5 mg), liraglutide 3.0 mg/day, or placebo for 26 weeks
• At 26 weeks, the 2.4 mg cagrilintide arm achieved a mean −9.7% body weight reduction vs. −3.0% for placebo and −9.0% for liraglutide 3 mg/day — demonstrating comparable efficacy to an approved GLP-1 agonist with a markedly better GI tolerability profile
• Vomiting was significantly lower with cagrilintide 2.4 mg compared to liraglutide (p=0.02), a finding with substantial clinical relevance given that vomiting is a primary driver of GLP-1 drug discontinuation
• Dose-response was confirmed across the 0.3–4.5 mg range; 2.4 mg was selected as the Phase 3 dose based on the benefit-risk profile

Phase 2 Type 2 Diabetes Trial — The Lancet (2023)

Frias et al. (The Lancet, 2023) evaluated cagrilintide 2.4 mg, CagriSema 2.4/2.4 mg, and semaglutide 2.4 mg head-to-head in adults with type 2 diabetes and obesity over 32 weeks:

• CagriSema 2.4/2.4 mg achieved −15.6% mean body weight reduction vs. −8.1% for cagrilintide 2.4 mg and −5.1% for semaglutide 2.4 mg
• HbA1c reduction was greatest with CagriSema: −2.2% vs. −1.8% for semaglutide and −0.9% for cagrilintide alone
• Cagrilintide as monotherapy demonstrated superior triglyceride and VLDL-C reduction compared to placebo — a metabolic benefit extending beyond weight loss
• No severe hypoglycemia was observed in any active treatment arm, consistent with the non-insulin-secretagogue mechanism of cagrilintide

Meta-Analysis Evidence (2024)

Dutta et al. (Indian Journal of Endocrinology and Metabolism, 2024) performed a systematic review and meta-analysis of 3 RCTs (n=430):

• CagriSema 2.4/2.4 mg produced a significantly greater percentage weight loss than semaglutide 2.4 mg: MD −9.07% (95% CI: −11.91, −6.23; p<0.00001)
• Cagrilintide 2.4 mg monotherapy demonstrated comparable weight loss to semaglutide 2.4 mg and liraglutide 3 mg, with a significantly lower rate of vomiting vs. both GLP-1 agents
• GI adverse events as a whole were significantly higher with CagriSema versus semaglutide alone — a key finding informing the risk-benefit calibration of combination therapy
• GRADE evidence certainty for weight loss outcomes was rated Low, reflecting high heterogeneity and publication bias potential — underscoring the importance of the larger Phase 3 dataset

Phase 3 Program — REDEFINE, REIMAGINE, and RENEW

REDEFINE 1 (CagriSema, obesity without T2DM): The landmark Phase 3 trial enrolling 3,417 adults with obesity or overweight with at least one comorbidity (excluding T2DM), comparing CagriSema 2.4/2.4 mg to placebo and each monotherapy over 68 weeks:

• CagriSema achieved 22.7% mean body weight reduction at 68 weeks — vs. 11.8% for cagrilintide 2.4 mg monotherapy, 16.1% for semaglutide 2.4 mg, and 3.2% for placebo
• 31.6% of participants on cagrilintide monotherapy achieved ≥15% weight loss vs. 4.7% with placebo
• No weight loss plateau was observed with CagriSema at 68 weeks, suggesting continued efficacy potential with extended treatment duration
• Results were published in the New England Journal of Medicine (June 2025)

REIMAGINE 2 (CagriSema, T2DM): Phase 3 trial comparing CagriSema to semaglutide (Ozempic) in adults with T2DM:

• CagriSema achieved a superior HbA1c reduction of 1.91 percentage points vs. 1.76 percentage points with semaglutide (Ozempic) at 68 weeks
• CagriSema also delivered 14.2% weight loss vs. 10.2% with Ozempic — no weight plateau observed
• 43% of CagriSema participants achieved ≥15% weight loss; 24% achieved ≥20% weight loss

Cagrilintide monotherapy — Phase 3 REDEFINE 1 arm: In the dedicated cagrilintide arm of REDEFINE 1, cagrilintide 2.4 mg monotherapy delivered 11.8% mean body weight reduction vs. 2.3% for placebo over 68 weeks, with 31.6% of participants achieving ≥15% weight loss.

RENEW Program (dedicated cagrilintide monotherapy Phase 3): Based on the REDEFINE 1 monotherapy results, Novo Nordisk announced plans to initiate a dedicated Phase 3 program for cagrilintide as a standalone agent for obesity, with the RENEW program scheduled to begin in Q4 2025.

Clinical Development

Cagrilintide is an investigational compound with an advanced late-stage clinical development program by Novo Nordisk:

• As a monotherapy, cagrilintide has no FDA approval and no NDA filed as of May 2026; it is advancing into the dedicated Phase 3 RENEW program
• As the cagrilintide component of CagriSema, Novo Nordisk submitted an NDA to the FDA in December 2025; FDA review is anticipated during 2026, with possible approval as the first once-weekly combination of a GLP-1 receptor agonist and an amylin analogue
• CagriSema is simultaneously under Phase 3 evaluation in the REIMAGINE program for type 2 diabetes management
• Cagrilintide has no approved therapeutic indication in any country globally as of May 2026

Regulatory Status

FDA (United States): Cagrilintide is not approved for any human therapeutic use. It is not listed on the FDA’s 503A Category 1, Category 2, or 503B bulk compounding substance lists; it is not a component of any FDA-approved drug product; and it is not the subject of a USP or NF monograph. Compounded cagrilintide does not qualify for exemptions under either section 503A or 503B of the FD&C Act. The FDA has specifically warned companies against selling unapproved cagrilintide products labeled “for research purposes” or “not for human consumption.”

WADA: Cagrilintide is not currently listed by name on the WADA Prohibited List. However, its mechanism of action via hormonal receptor pathways may attract scrutiny under evolving anti-doping frameworks. Athletes subject to anti-doping rules should confirm current status with their national anti-doping organization before any use.

International: No regulatory authority — EMA, Health Canada, TGA, or otherwise — has approved cagrilintide for any indication as of May 2026. Its availability is currently limited to clinical trial enrollment and unregulated research chemical suppliers, the latter of which carry significant quality and safety concerns.

Cagrilintide’s safety data derives from controlled Phase 1b and Phase 2 clinical trials, supplemented by the emerging Phase 3 REDEFINE 1 dataset — a more robust evidence base than most investigational compounds, but still limited relative to the post-approval pharmacovigilance available for established GLP-1 agents. Notably, cagrilintide’s GI tolerability profile compares favorably to GLP-1 agonists on vomiting, though less favorably when combined with semaglutide in the CagriSema formulation.

Established Adverse Effects from Clinical Trials

Adverse effects are dose-dependent and consistent with the amylin/calcitonin receptor agonist drug class:

• Nausea: The most common adverse event; dose-dependent and typically transient, most prominent during dose escalation; incidence significantly higher than placebo (OR ~0.97 vs. placebo, but higher with CagriSema vs. semaglutide)
• Vomiting: Reported but — critically — at a significantly lower rate than semaglutide or liraglutide in head-to-head comparisons; a meaningful tolerability advantage for cagrilintide monotherapy
• Diarrhea: Reported across active dose groups; typically mild to moderate and transient
• Constipation: Less common than nausea; consistent with gastric emptying delay as the mechanistic driver
• Injection site reactions: Observed at significantly higher rates with cagrilintide vs. placebo in the Phase 2 Lau et al. trial; clinical significance under continued evaluation in Phase 3
• Increased GI adverse events with CagriSema: The combination product significantly increases overall GI adverse events and vomiting compared to semaglutide monotherapy — a key risk-benefit consideration for CagriSema prescribing
• Discontinuation rates due to GI adverse events (nausea-driven specifically) were approximately 1.0% with cagrilintide vs. 0.1% with placebo in the REDEFINE 1 trial

Potential Serious Adverse Effects Under Evaluation

Theoretical or signal-based risks requiring monitoring in larger, longer-duration trials:

• Medullary thyroid carcinoma (MTC): Cagrilintide is contraindicated in individuals with personal or family history of MTC due to its structural similarity to calcitonin, which may theoretically influence thyroid C-cell activity — the same class concern carried by all GLP-1 agonists
• Multiple endocrine neoplasia type 2 (MEN2): Excluded from clinical trials; calcitonin receptor pathway overlap creates a theoretical risk consistent with the calcitonin-family drug class
• Cardiovascular effects: No elevated cardiovascular signal in Phase 2; a comprehensive cardiovascular outcomes trial analogous to the SELECT trial for semaglutide has not yet been conducted; long-term MACE data remain unavailable as of May 2026
• Lean mass loss: As with all significant weight-loss pharmacotherapies, the body composition question — whether cagrilintide-induced weight loss disproportionately reduces lean body mass and bone mineral density — remains under evaluation in Phase 3 body composition substudies
• Severe renal impairment: Insufficient safety data in patients with eGFR <30 mL/min/1.73 m²; use with caution until Phase 3 data fully characterize renal safety
• Serious adverse events (SAEs) with cagrilintide monotherapy were observed at a higher rate vs. semaglutide in one meta-analysis (RR 1.83; 95% CI: 1.03–3.24) — a signal that requires confirmation and mechanistic characterization in the larger RENEW Phase 3 dataset

Manufacturing Quality in the Unregulated Market

For cagrilintide obtained outside of clinical trials through research chemical or peptide vendors:

• No cGMP manufacturing oversight applies; contamination with residual TFA, heavy metals, endotoxins, and microbial load represent serious injection safety risks
• Product identity and potency cannot be verified; mislabeling, underdosing, and substitution with structurally similar compounds are documented risks across the unregulated peptide market
• The FDA has explicitly warned consumers against purchasing cagrilintide from vendors marketing it “for research purposes” or “not for human consumption”

1. Lau DCW, et al. (2021). Once-weekly cagrilintide for weight management in people with overweight and obesity: A multicentre, randomised, double-blind, placebo-controlled and active-controlled, dose-finding phase 2 trial. The Lancet, 398(10317), 2160–2172. https://doi.org/10.1016/S0140-6736(21)01751-7
2. Enebo LB, et al. (2021). Safety, tolerability, pharmacokinetics, and pharmacodynamics of concomitant administration of multiple doses of cagrilintide with semaglutide 2.4 mg for weight management: A randomised, controlled, phase 1b trial. The Lancet, 397(10282), 1736–1748. https://doi.org/10.1016/S0140-6736(21)00845-X
3. Frias JP, et al. (2023). Efficacy and safety of co-administered once-weekly cagrilintide 2.4 mg with once-weekly semaglutide 2.4 mg in type 2 diabetes: A multicentre, randomised, double-blind, active-controlled, phase 2 trial. The Lancet, 402(10403), 720–730.
4. Dutta D, et al. (2024). Efficacy and Safety of Cagrilintide Alone and in Combination with Semaglutide (Cagrisema) as Anti-Obesity Medications: A Systematic Review and Meta-Analysis. Indian Journal of Endocrinology and Metabolism, 28(5), 436–444. https://pmc.ncbi.nlm.nih.gov/articles/PMC11642503/
5. Jastreboff AM, et al. (2025). CagriSema 2.4 mg / 2.4 mg demonstrated 22.7% mean weight reduction in adults with overweight or obesity in REDEFINE 1. New England Journal of Medicine. https://doi.org/10.1056/NEJMoa2501513
6. Novo Nordisk. (2025, September). Novo Nordisk presents phase 3 data for next-generation amylin cagrilintide leading to advancement in dedicated obesity phase 3 program. Press Release. https://www.biospace.com/press-releases/novo-nordisk-presents-phase-3-data
7. Novo Nordisk. (2025, December). Novo Nordisk files for FDA approval of CagriSema. PR Newswire. https://www.prnewswire.com/news-releases/novo-nordisk-files-for-fda-approval-of-cagrisema
8. FSMB Letter to FDA. (2025, June). Cagrilintide compounding regulatory status. https://www.fsmb.org/siteassets/communications/fdaCagrilintide.pdf
9. Gæde J, et al. (2025). Cagrilintide lowers bodyweight through brain amylin receptor pathways. eBioMedicine. https://www.thelancet.com/journals/ebiom/article/PIIS2352-3964(25)00280-4
10. Zhang X, et al. (2025). Structural and dynamic features of cagrilintide binding to calcitonin-family receptors. Nature Communications. https://www.nature.com/articles/s41467-025-58680-y
11. Kitic M, et al. (2021). Development of Cagrilintide, a Long-Acting Amylin Analogue. Journal of Medicinal Chemistry, 64(17). https://pubs.acs.org/doi/10.1021/acs.jmedchem.1c00565
12. ClinicalTrials Arena. (2026, February). Novo Nordisk’s CagriSema outperforms Ozempic in Phase III REIMAGINE trial. https://www.clinicaltrialsarena.com/news/novo-nordisks-cagrisema-outperforms-ozempic-in-phase-iii-trial/