New Amylin Drug Petrelintide Cuts Body Weight by Nearly 10% in Phase 2 Trial
Once-weekly petrelintide achieved up to 9.8% weight loss at 28 weeks with far better GI tolerability than GLP-1 drugs — a potentially major new obesity therapy.
Summary
Petrelintide, a novel long-acting amylin analogue developed by Zealand Pharma, produced clinically meaningful weight loss in adults with obesity in a rigorous phase 2 trial. Unlike GLP-1 receptor agonists such as semaglutide, petrelintide works through a distinct mechanism — mimicking the satiety hormone amylin — potentially offering a new option or combination partner for obesity treatment. Across five dose levels, participants lost between 7.9% and 9.8% of body weight at 28 weeks compared to just 1.7% with placebo. Weight continued to fall through week 42, reaching up to 10.7% total reduction. Critically, gastrointestinal side effects were mild, with nausea the only notable complaint, and rates of vomiting, diarrhea, and constipation were similar to placebo — a meaningful advantage over current standard-of-care agents.
Detailed Summary
Obesity is a major driver of accelerated aging, metabolic disease, cardiovascular risk, and reduced healthspan. While GLP-1 receptor agonists have transformed obesity treatment, they carry significant gastrointestinal side effects and their mechanism may limit long-term durability or combination use. Petrelintide, a once-weekly injectable amylin analogue, targets a distinct neurohormonal pathway for appetite regulation, raising the possibility of an effective, better-tolerated alternative or add-on therapy.
The ZUPREME 1 trial was a randomized, double-blind, placebo-controlled phase 2 study conducted across 32 sites in Poland, Romania, and the USA. Adults without type 2 diabetes and with a BMI of at least 30 kg/m² (or ≥27 kg/m² with comorbidities) were randomized 5:1 to one of five weekly maintenance doses of petrelintide (1.0–9.0 mg) or placebo over 42 weeks including dose escalation. The primary endpoint was percentage body weight change from baseline at 28 weeks. A total of 485 participants received at least one dose.
At 28 weeks, all petrelintide doses produced significantly greater weight loss than placebo (-1.7%). The 5.0 mg dose achieved the greatest reduction at -9.8%, with other doses ranging from -7.9% to -9.4%. Estimated treatment differences versus placebo ranged from -6.2% to -8.1%. Weight loss continued through week 42, reaching up to -10.7% with the highest doses — suggesting the drug had not yet reached its plateau effect.
The tolerability profile was notably favorable. Nausea occurred in 20% of petrelintide participants versus 6% on placebo but was predominantly mild and concentrated during dose escalation. Vomiting, diarrhea, and constipation rates were low and comparable to placebo — a striking contrast to the GI burden commonly seen with incretin-based therapies.
Petrelintide's distinct mechanism and favorable tolerability position it as a potentially important addition to the obesity treatment landscape, whether as monotherapy or in combination with GLP-1 agents. Limitations include the short trial duration, predominantly White study population, and the fact that this summary is based on the abstract only. Phase 3 data will be needed to confirm long-term efficacy, safety, and effects on cardiometabolic outcomes.
Key Findings
- Petrelintide 5.0 mg produced 9.8% body weight loss at 28 weeks vs. 1.7% for placebo — a difference of 8.1 percentage points.
- Weight loss continued through week 42, reaching up to 10.7% total reduction, suggesting no plateau by trial end.
- Nausea occurred in 20% of petrelintide users but was predominantly mild and limited to the dose-escalation phase.
- Vomiting, diarrhea, and constipation rates were similar to placebo — a key tolerability advantage over GLP-1 drugs.
- Petrelintide's amylin-based mechanism is distinct from incretins, opening the door to combination obesity therapies.
Methodology
ZUPREME 1 was a multicenter, randomized, double-blind, placebo-controlled phase 2 trial across 32 sites in Poland, Romania, and the USA. A total of 485 adults without type 2 diabetes and with obesity were randomized 5:1 to once-weekly subcutaneous petrelintide at one of five dose levels (1.0–9.0 mg) or placebo over 42 weeks. The primary endpoint was percentage body weight change from baseline at 28 weeks, analyzed in all participants who received at least one dose.
Study Limitations
This summary is based on the abstract only, as the full paper was not available for review. The 42-week trial duration is insufficient to assess long-term weight maintenance, cardiovascular outcomes, or durability of effect. The study population was 86% White and excluded people with type 2 diabetes, limiting generalizability; larger and more diverse phase 3 trials are essential.
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