CagriSema vs AOD-9604.

CagriSema is a fixed-combination injectable investigational obesity therapeutic developed by Novo Nordisk that co-formulates two long-acting peptide analogues in a single once-weekly subcutaneous injection: cagrilintide, a long-acting amylin receptor agonist (analogue of the pancreatic hormone amylin), and semaglutide, a GLP-1 (glucagon-like peptide-1) receptor agonist already marketed for diabetes and obesity. It pairs the same semaglutide molecule found in Ozempic and Wegovy with a novel amylin analogue, making it the first amylin-plus-GLP-1 dual-hormone combination to reach late-stage clinical development for weight management.

AOD-9604 ("Advanced Obesity Drug 9604") is a synthetic 16-amino-acid peptide corresponding to the C-terminal lipolytic region of human growth hormone (hGH), residues 177–191, with an added tyrosine at the N-terminus. It was engineered in the 1990s by researchers at Monash University and developed by the Australian biotech Metabolic Pharmaceuticals as an orally-investigated anti-obesity agent. The design goal was to isolate hGH's fat-mobilizing activity while leaving out the growth-promoting, IGF-1-stimulating actions of the full hormone.

The two components act on complementary appetite-regulating pathways. Semaglutide is a GLP-1 receptor agonist that slows gastric emptying and signals through hypothalamic and brainstem circuits to reduce hunger and increase satiety. Cagrilintide is an amylin analogue that engages amylin and calcitonin-family receptors, also acting on the area postrema and hypothalamus to promote satiation and reduce food intake; amylin signaling is thought to modulate leptin sensitivity and meal termination through a partly distinct mechanism from GLP-1. The rationale is that combining the two yields additive or complementary reductions in energy intake beyond either agent alone.

In rodent models, AOD-9604 reproduces the lipolytic (fat-breakdown) and fat-oxidation–promoting effects of full-length growth hormone without binding the GH receptor and without raising IGF-1. Mechanistic work in obese and beta-3-adrenergic-receptor knockout mice indicated its effect on fat metabolism is associated with modulation of beta-3 adrenergic receptor activity and increased lipolysis and fat oxidation rather than classic GH-receptor signaling. Because it does not engage the GH receptor, it was hypothesized to avoid the insulin-resistance and tissue-growth liabilities of GH itself. Importantly, the cleanly receptor-independent, IGF-1-sparing profile is best characterized in animal and in-vitro work, not firmly established in humans.

Unlike most "research peptides," CagriSema has substantial human Phase 3 data from the REDEFINE program. In REDEFINE 1 (Garvey et al., NEJM 2025; 68 weeks, ~3,400 adults with obesity/overweight without diabetes), CagriSema produced roughly 20% mean body-weight loss versus semaglutide alone, cagrilintide alone, and placebo. In REDEFINE 2 (Davies et al., NEJM 2025), conducted in adults with overweight/obesity and type 2 diabetes, CagriSema reduced body weight and HbA1c versus placebo, though weight loss in the diabetes population was more modest, consistent with the general pattern for incretin therapies. REDEFINE 5 (Yamauchi et al., Lancet Diabetes & Endocrinology 2026) evaluated it versus semaglutide alone in Japan and Taiwan. Importantly, in the open-label head-to-head REDEFINE 4 trial, CagriSema (~23% weight loss on the efficacy estimand) did NOT meet its primary endpoint of non-inferiority versus tirzepatide (Zepbound, ~25.5%), a notable negative result that tempers claims of clear superiority over existing dual/incretin therapies.

Preclinical evidence is the strongest part of the AOD-9604 record: chronic dosing reduced body-weight gain and increased fat oxidation in obese mice (Heffernan et al., Int J Obes, 2001; PMID 11673763). It progressed into human obesity trials in the early-mid 2000s; a 12-week randomized study reported only a modest separation from placebo (on the order of ~1–2 kg), and development was halted around 2007 after a larger ~24-week trial failed to show meaningful weight-loss efficacy, particularly once diet and exercise were standardized. No peer-reviewed pivotal trial demonstrates clinically useful weight loss, and there is no robust human evidence for the commonly marketed claims around cartilage, joint, or tendon repair: those rest on limited preclinical/early work. In short, the human data are negative-to-thin for obesity and largely absent for other indications.

The most common adverse events in the REDEFINE trials were gastrointestinal: nausea, vomiting, diarrhea, and constipation, consistent with the known class effects of GLP-1 receptor agonists and amylin analogues; these were generally mild-to-moderate and most frequent during dose escalation. As with other GLP-1-based therapies, label-level concerns for the class include gallbladder events, pancreatitis risk signals, and a boxed thyroid C-cell tumor warning carried by semaglutide products (based on rodent data). Long-term safety, durability after discontinuation, and outcomes in broader real-world populations remain incompletely characterized because the compound is still investigational and only recently filed for approval. No legitimate medical use exists outside clinical trials and (pending) regulatory approval, and gray-market "research" cagrilintide/semaglutide products carry purity, sterility, and dosing-error risks.

Across the obesity trials, AOD-9604 was generally reported as well tolerated with a clean short-term safety signal, which is part of why it was later nominated for compounding review; however, these data come from time-limited studies and do not establish long-term safety. There is no established safety profile for chronic use, for injectable research-grade ("gray market") product, or for the unindicated cosmetic, joint, and anti-aging uses now marketed online. Purity, identity, and contamination of non-pharmaceutical material are real concerns, underscored by published forensic identification of illicit AOD9604 preparations (Drug Testing and Analysis, 2014; PMID 24976118). No dosing or administration guidance is provided here.

CagriSema is investigational and not approved by the FDA or EMA as of mid-2026; Novo Nordisk submitted a U.S. New Drug Application for chronic weight management on December 18, 2025, with a regulatory decision anticipated in late 2026. Its individual components have separate statuses: semaglutide is FDA-approved (e.g., Wegovy, Ozempic), while cagrilintide alone is not approved.

AOD-9604 is not approved by the FDA (or any major regulator) for any therapeutic use; its obesity development program was discontinued, and it remains investigational/research-use-only. The FDA has evaluated it among nominated bulk drug substances for pharmacy compounding under section 503A and has flagged peptide candidates of this type as raising significant safety questions; it is also prohibited in sport and tested for by anti-doping authorities under the WADA framework.