Petrelintide's GI Differentiation Claim Is Phase 2 Only — Phase 3 Design Will Determine Whether It Matters

Zealand Pharma's Petrelintide Phase 2 ZUPREME-1 Data Published

Zealand Pharma announced the publication of results from its Phase 2 ZUPREME-1 trial for investigational petrelintide in The Lancet Diabetes & Endocrinology, with additional data to be presented at EASD 2026. The randomized, double-blind, placebo-controlled trial in 485 adults with obesity or overweight demonstrated clinically meaningful weight loss of up to 10.7% from baseline to week 42 for petrelintide versus 1.7% for placebo. The drug showed a gastrointestinal tolerability profile comparable to placebo, with no vomiting or discontinuations due to GI adverse events at the maximally effective dose. Petrelintide also led to significant improvements in cardiometabolic risk factors, including reductions in waist circumference, high-sensitivity C-reactive protein, and triglycerides. A global Phase 3 ZUPREME registrational program has been initiated.

• Petrelintide demonstrated robust efficacy in chronic weight management, achieving mean reductions in body weight from baseline to week 42 of up to 10.7% (efficacy estimand) and 10.2% (treatment policy estimand), compared to 1.7% and 1.4% for placebo, respectively. These double-digit reductions highlight petrelintide's potential as a highly effective treatment option.
• A key finding was petrelintide's favorable gastrointestinal adverse event profile, which was generally mild and comparable to placebo. Notably, at the maximally effective dose, there were no reported cases of vomiting and no treatment discontinuations attributed to gastrointestinal adverse events, addressing a common challenge with current weight management therapies.
• Beyond weight loss, petrelintide significantly improved several cardiometabolic risk factors. Patients experienced reductions in waist circumference of up to 10.8 cm, high-sensitivity C-reactive protein by up to 41%, and triglycerides by up to 21%, alongside a mean reduction in pulse rate of up to 2.9 bpm, indicating comprehensive health benefits.
• Petrelintide, a long-acting human amylin analog, is designed for once-weekly subcutaneous administration and is now progressing into a global Phase 3 ZUPREME registrational program for chronic weight management. Its mechanism involves amylin receptor activation, which helps reduce body weight by restoring leptin sensitivity and inducing satiety. Zealand Pharma is also collaborating with Roche on its development.

Addressing Unmet Needs in Chronic Weight Management with Petrelintide

Chronic weight management remains one of the most therapeutically complex challenges in modern medicine, with no single intervention delivering durable, safe, and broadly accessible outcomes. Current pharmacological and surgical approaches each carry meaningful limitations that constrain their long-term utility across diverse patient populations.

• GI tolerability and treatment adherence: GLP-1 receptor agonists such as semaglutide and tirzepatide — among the most efficacious agents available — are frequently associated with nausea, vomiting, diarrhea, and constipation, particularly during dose escalation. These effects are common across anti-obesity medications and can impact adherence and lead to treatment discontinuation.

• Weight regain following pharmacotherapy cessation: Discontinuation of GLP-1 receptor agonist therapy is consistently followed by substantial weight regain, with a large proportion occurring during the early post-cessation period. This pattern reflects restoration of appetite, compensatory increases in orexigenic hormones such as ghrelin, and alterations in incretin balance — underscoring the chronic, relapsing nature of obesity and the limited durability of pharmacotherapy alone.

• Loss of fat-free mass during weight loss interventions: Both bariatric surgery and GLP-1-based pharmacotherapy raise concerns about unintended loss of muscle mass, which compromises physical functionality, quality of life, and long-term metabolic health — particularly in individuals with sarcopenic obesity or those at risk of frailty. Current weight-loss strategies often fail to adequately address the need to maintain fat-free mass.

• Limitations of bariatric surgery in specific populations: In patients with Prader-Willi syndrome, bariatric surgery failed to produce sustainable long-term weight loss or comorbidity resolution over a 10-year follow-up, with mean percentage of total weight loss declining from 24.7% at 2 years to 0% at 10 years. More broadly, surgery is accompanied by higher risks and lower uptake compared to lifestyle and pharmacological approaches.

• Access, cost, and safety monitoring barriers: High costs, supply shortages, and unequal access pose significant barriers to widespread implementation, particularly in low-resource settings. Gastrointestinal side effects and long-term safety concerns — including emerging risks such as sarcopenia and joint degeneration — require close monitoring, while earlier agents such as fenfluramine and sibutramine were withdrawn due to serious adverse effects.

• Increased poison control exposures: Following FDA approval of semaglutide (Wegovy) for chronic weight management in June 2021, reported GLP-1 receptor agonist exposures increased by 1.16 per month and hospital utilization from exposures increased by 0.351 per month. The most common adverse effects in exposure cases were nausea (28.0%), vomiting (25.5%), and dizziness (6.0%), with administration errors accounting for 91.7% of exposures involving compounded GLP-1 receptor agonist products.

ZUPREME-1 Phase 2: Petrelintide's Efficacy and Tolerability Profile

Recent clinical evidence continues to reinforce the differentiated efficacy and tolerability profiles of GLP-1–based therapies in chronic weight management, with head-to-head and placebo-controlled data now available across diverse populations and treatment contexts.

• Retrospective Cohort Study (Tirzepatide vs. Semaglutide; Truveta EHR Data): Among 2,396 on-treatment adults with obesity without diabetes, tirzepatide produced a mean 6-month weight reduction of –11.15% versus –8.83% with semaglutide (adjusted difference –2.32%-points; 95% CI: –3.17, –1.48). Tirzepatide-treated patients more frequently achieved 5%, 10%, 15%, and 20% weight-reduction targets, and demonstrated greater reductions in BMI, blood pressure, and haemoglobin A1c. Notably, this comparative advantage emerged despite a higher proportion of semaglutide-treated patients receiving higher doses (≥1.7 mg: 67.7% vs. ≥10 mg tirzepatide: 42.4%).

• SURMOUNT-1, -3, and -4 Post Hoc Analysis (Tirzepatide with Concomitant Weight-Inducing Medications): In participants taking at least one concomitant weight-inducing medication, tirzepatide maintained weight loss comparable to primary study results. Mean percentage weight change versus placebo at 72 weeks ranged from –13.3% (95% CI: –16.0% to –10.7%) for 5 mg to –21.3% (95% CI: –23.9% to –18.7%) for 15 mg in SURMOUNT-1, and –26.1% (95% CI: –30.0% to –22.3%) for the maximum tolerated dose in SURMOUNT-3. At 88 weeks in SURMOUNT-4, the maximum tolerated dose yielded –18.6% (95% CI: –20.9% to –16.3%). Approximately one-fifth of participants across all three trials used one or more weight-inducing medications.

• Randomized Clinical Trial — Semaglutide in Schizophrenia Spectrum Disorders: In a multicenter, double-blind, placebo-controlled trial (n=73 randomized), adjunctive once-weekly subcutaneous semaglutide 1 mg over 26 weeks significantly reduced body weight (–9.2 kg; 95% CI: –13.3 to –5.1 kg; P<.001), waist circumference (–7.0 cm; 95% CI: –10.6 to –3.3 cm; P<.001), and fat mass (–6.1 kg; 95% CI: –10.2 to –1.9 kg; P=.006) in individuals with schizophrenia spectrum disorders on clozapine or olanzapine. HbA1c was also significantly reduced (mean difference –0.25%; 95% CI: –0.33 to –0.16; P<.001), with 43% of semaglutide-treated participants achieving low-risk HbA1c levels (<5.4%) versus 3% with placebo. Gastrointestinal adverse events were common but mild and transient; psychiatric adverse events were similar across groups.

• Systematic Review and Meta-Analysis — Tirzepatide in Non-Diabetic Adults (6 RCTs): Compared with placebo, tirzepatide produced a mean difference in percentage body weight of –16.32% (95% CI: –18.35 to –14.29) and –13.95 kg in absolute weight (95% CI: –18.83 to –9.07), alongside significant reductions in BMI (MD –5.89 kg/m²; 95% CI: –8.97 to –2.81) and waist circumference (MD –12.31 cm; 95% CI: –13.93 to –10.68). GI side effects were prominent: nausea (RR 3.11; 95% CI: 2.74–3.54), vomiting (RR 5.94; 95% CI: 4.50–7.85), diarrhea (RR 2.92; 95% CI: 2.53–3.37), and constipation (RR 2.85; 95% CI: 2.38–3.42). While overall serious adverse events were not statistically significant (RR 0.93; 95% CI: 0.76–1.13), serious GI events (RR 3.07; 95% CI: 2.03–4.66) and discontinuation due to adverse events (RR 2.29; 95% CI: 1.74–3.01) were significantly elevated versus placebo.

Petrelintide's Amylin Analog MoA and Competitive Landscape

Petrelintide is a dual amylin and calcitonin receptor agonist (DACRA) under Phase II clinical investigation for obesity. Several other agents sharing this mechanistic class — targeting amylin receptors (AMYR) and/or the calcitonin receptor (CTR) to induce satiety, reduce food intake, and promote weight loss — are advancing through clinical and late preclinical development.

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Petrelintide's Tolerability Poises Amylin Agonists for Broader Impact

The recent publication of petrelintide's Phase 2 ZUPREME-1 trial results in The Lancet Diabetes & Endocrinology, alongside plans for further data presentation, signals a potentially impactful entry into the evolving obesity treatment landscape. As an amylin receptor agonist, petrelintide joins a class of emerging therapies that leverage central mechanisms to control hunger, gastric motility, and energy metabolism. What truly differentiates petrelintide in this increasingly competitive field is its remarkable tolerability profile.

While other amylin analogues and GLP-1 receptor agonists have demonstrated significant weight loss, they often come with gastrointestinal side effects like nausea and vomiting, which can lead to treatment discontinuation. Petrelintide's Phase 2 data, showing a GI tolerability comparable to placebo with no vomiting or discontinuations due to GI adverse events at the maximally effective dose, addresses a critical unmet need. This could significantly enhance patient adherence and expand the pool of individuals who can effectively manage their weight with pharmacotherapy.

Beyond weight reduction, the observed improvements in cardiometabolic risk factors such as waist circumference, high-sensitivity C-reactive protein, and triglycerides are particularly compelling. Research indicates that long-acting AMYR agonists may offer therapeutic benefits in conditions like fatty liver disease, diabetes-associated kidney complications, and resistant hypertension. This suggests petrelintide could offer more than just weight loss, potentially acting as a disease-modifying agent for obesity-related comorbidities.

However, the path forward is not without challenges. The obesity market is rapidly expanding with numerous established and investigational therapies, including powerful dual and multi-agonists. Petrelintide will need to demonstrate sustained efficacy and safety in its global Phase 3 program to carve out a significant market share. While its tolerability is a strong asset, the broader class risk of GI side effects, even if mitigated, will remain a consideration. Ultimately, petrelintide's progress will be closely watched as it aims to offer a differentiated and highly tolerable option for precision obesity management.