Three percent of the patients on petrelintide vomited. On the placebo injection, the figure was 6.2 percent. An experimental obesity shot made fewer people sick than a saltwater control did.
That inversion is the entire pitch for the amylin class, and it arrived with hard numbers this week. At the American Diabetes Association meeting in New Orleans, Zealand Pharma and Roche presented the full Phase 2 ZUPREME-1 dataset ↗ for petrelintide ↗, a once-weekly amylin analog, in 485 adults with overweight or obesity (mean body mass index 36.7, average starting weight 107.1 kg). At the top dose, patients lost up to 10.7 percent of their body weight over 42 weeks, against 1.7 percent on placebo.
Ten percent is not a headline number in 2026. The GLP-1 and dual-agonist drugs that defined obesity treatment now post weight loss in the high teens to high twenties. Judged on that axis alone, petrelintide looks second-tier.
The axis is the point. Amylin is a hormone the pancreas releases alongside insulin, and it signals fullness through receptors in the brainstem rather than by aggressively slowing the gut the way GLP-1 drugs do. Less gut-slowing means less nausea and vomiting, the side effects that drive people off the incretins within the first year. The bet behind the whole class is that a drug people can tolerate for a decade beats a stronger drug they quit by month nine.
The tolerability data backs the bet. Nausea ran 19.6 percent on petrelintide against 6.2 percent on placebo, the one gut symptom that was clearly elevated, but more than three-quarters of those events were mild and only 1.5 percent of patients stopped the drug for stomach trouble. Vomiting, the symptom that most reliably ends a GLP-1 prescription, came in below placebo. Dose escalation worked: 88 to 98 percent of patients reached their target maintenance dose.
The cardiometabolic markers moved in the right direction too. Waist circumference fell 7.9 to 10.8 cm against 4.3 cm on placebo. High-sensitivity C-reactive protein, a blood marker of inflammation, dropped 17 to 41 percent. Triglycerides fell 12 to 21 percent. In the company's announcement, the obesity researcher W. Timothy Garvey tied the result to long-term adherence rather than peak weight loss, which is the case the amylin developers have made from the start.
Petrelintide works through CALCR/RAMP, the amylin receptor complex ↗, not the GLP-1 receptor, which is why its side-effect profile reads so differently from everything else in the obesity clinic. We covered the drug's move into Phase 3 in late April ↗; ZUPREME-1 is the detailed efficacy and safety data that decision rested on. Roche and Zealand say the Phase 3 program for chronic weight management starts in the second half of 2026.
The amylin case has always been a long-game argument. If the class can hold 10 percent weight loss with placebo-level tolerability, the question stops being how much weight a drug takes off in a trial and becomes how many years a patient stays on it in real life.