On August 23, 2026, Phase IIIa data from the REDEFINE 1 trial showed that 60 percent of adults receiving once-weekly cagrilintide–semaglutide lost at least 20 percent of their body weight over 68 weeks, a threshold clinicians have historically associated with bariatric surgery rather than pharmacotherapy. Twenty-three percent of participants shed 30 percent or more. The results, published in The New England Journal of Medicine and reported by Applied Clinical Trials, rank among the most significant weight reductions recorded in a Phase 3 anti-obesity study. Yet no adult outside the trial can obtain the combination. Novo Nordisk has filed for U.S. approval, but no launch price and no marketing authorization exist in any major market.
The trial (NCT05567796) enrolled 3,417 adults without diabetes who carried a body-mass index of 30 or higher, or 27 or higher with at least one weight-related complication. Investigators assigned participants in a 21:3:3:7 ratio to the fixed-dose combination at 2.4 mg of each agent (n = 2,108), semaglutide 2.4 mg alone (n = 302), cagrilintide 2.4 mg alone (n = 302), or placebo (n = 705), with lifestyle counseling in every arm.
Additive efficacy from two receptor pathways
Under the treatment-policy estimand, the combination group recorded a mean 20.4 percent body-weight reduction versus 3.0 percent with placebo, a 17.3-percentage-point difference (P < .001). Semaglutide monotherapy produced 14.9 percent; cagrilintide monotherapy produced 11.8 percent, according to a post hoc analysis in Pharmacy Times. The combination's advantage over semaglutide alone measured 5.5 additional percentage points.
Cagrilintide is a long-acting synthetic analog of amylin, a hormone co-secreted with insulin that slows gastric emptying and signals fullness through receptors in the hindbrain's area postrema. Semaglutide, marketed as Wegovy, activates GLP-1 receptors concentrated in the hypothalamus. Because the two compounds engage distinct neural circuits, the trial authors attributed the additive weight loss to complementary satiety signaling rather than a single amplified pathway. The structural logic of these synthetic hormones—short amino-acid chains engineered for receptor specificity—follows the design principles outlined in what are peptides.
Adverse events in the combination arm were predominantly gastrointestinal and graded mild to moderate, consistent with the known tolerability profile of weight-loss peptides in this class.
NDA filed; pricing and authorization remain undefined
Novo Nordisk submitted a New Drug Application for CagriSema to the U.S. Food and Drug Administration, as Patient Care Online reported. Neither cagrilintide monotherapy nor the fixed-dose combination holds marketing authorization in the United States or the United Kingdom as of August 2026. No launch price has been published. Coverage for anti-obesity injectables already varies sharply between commercial insurers and public programmes such as Medicaid or national health services, and the absence of a confirmed reimbursement code means the adults most likely to benefit from the additional 5.5 percentage points—particularly those who plateaued on semaglutide alone—have no defined route to the drug outside a research protocol.
REDEFINE 1 excluded adults with type 2 diabetes. A parallel trial, REDEFINE 2, is evaluating the same combination in that population, and separate NEJM reporting has described weight-loss and glycemic outcomes there. The efficacy observed in REDEFINE 1 cannot be extrapolated to patients managing concurrent diabetes until those data are replicated across primary-care and lower-resource settings where GLP-1 access is already constrained.
The 68-week follow-up also leaves durability unresolved. Trial retention strategies including coaching calls and injection reminders kept dropout low, but the design does not address whether weight loss persists after discontinuation.
Until the FDA issues a decision on the CagriSema NDA and Novo Nordisk sets a launch price, the 60 percent figure describes what 2,108 monitored trial participants achieved, not what is available to the broader population living with obesity.
