Roche insists amylin obesity drug still valuable for patients who ‘don’t want side effects’

Roche Defends Petrelintide's Value Despite Phase 2 Efficacy Shortfall

Roche is defending its amylin analog petrelintide for obesity, despite its Phase 2 ZUPREME-1 study showing a 9% placebo-controlled weight reduction at 42 weeks, which fell short of analyst expectations (e.g., William Blair expected 12%). CEO Thomas Schinecker emphasized the drug's high tolerability, with only 4.8% of patients at the highest dose dropping out due to toxicities, comparable to placebo (4.9%). Schinecker positions petrelintide as a valuable option for maintenance or combination regimens, particularly for patients prioritizing fewer side effects over maximum weight loss, contrasting it with GLP-1/GIP drugs that offer higher efficacy but often lead to higher discontinuation rates.

• Roche CEO Thomas Schinecker highlighted petrelintide's high tolerability as its primary benefit, positioning it for patients who prioritize fewer side effects over aggressive weight loss. In the ZUPREME-1 study, only 4.8% of patients on the highest petrelintide dose discontinued due to toxicities, a rate nearly identical to the 4.9% in the placebo arm. This tolerability is seen as crucial for maintenance treatment and combination therapies, offering an alternative to GLP-1/GIP drugs known for higher efficacy but also higher discontinuation rates due to side effects.
• The Phase 2 ZUPREME-1 study for petrelintide demonstrated a 9% placebo-controlled weight reduction over 42 weeks in patients with obesity or who are overweight. This result, announced last month by Roche and Zealand Pharma, underperformed analyst expectations, with firms like William Blair anticipating at least 12% weight loss. The disappointment led to a significant market reaction, with Zealand Pharma's shares plummeting as much as 32% following the data readout, reflecting investor concerns about petrelintide's competitive standing against existing and emerging weight-loss therapies.
• Despite petrelintide's efficacy falling short of some competitors, Roche remains committed to the obesity market, aiming to be a 'top three player.' CEO Schinecker reiterated that amylin drugs like petrelintide fill a niche for patients seeking safer, more tolerable options, even if GLP-1/GIPs offer greater than 20% weight loss. Separately, Roche reported mixed first-quarter 2026 financial results, with CHF 14.72 billion in revenues, a 5% year-on-year decline attributed to currency appreciation, though sales grew 6% at constant currencies.

ZUPREME-1: Petrelintide's Efficacy and Tolerability Data Unveiled

Recent obesity and overweight studies have demonstrated significant advances in pharmacological interventions, particularly with GLP-1/GIP receptor agonists, alongside emerging evidence for dietary and lifestyle interventions. The data spans multiple therapeutic approaches with robust efficacy and safety profiles across diverse patient populations.

SURMOUNT Trials (SURMOUNT-1, SURMOUNT-3, SURMOUNT-4) evaluated tirzepatide, a dual GIP/GLP-1 receptor agonist administered once weekly at 5-15 mg doses, showing medium-term weight reduction of 16.03% versus placebo with 3.6-fold higher likelihood of achieving ≥5% weight loss, though associated with increased non-serious adverse events (RR 1.33) and withdrawal due to adverse events (RR 2.06).

VENTURE Study assessed VK2735, a novel GLP-1/GIP receptor dual agonist, demonstrating dose-dependent weight reductions ranging from 9.1% (2.5 mg) to 14.7% (15 mg) at 13 weeks, with 93% of active treatment participants achieving ≥5% weight reduction compared to 12% with placebo, and predominantly gastrointestinal adverse events that decreased after dose titration.

Liraglutide meta-analysis encompassing 24 RCTs with 9,937 participants showed moderate-certainty evidence for 4.72% weight reduction and 2.1-fold increased likelihood of ≥5% weight loss, but was associated with increased serious adverse events (RR 1.20) and nearly doubled withdrawal rates due to adverse events (RR 1.98).

Mazdutide studies involving five RCTs of the dual GLP-1/glucagon receptor agonist demonstrated 12.42% body weight reduction with dose-dependent efficacy, alongside improvements in systolic blood pressure (-7.68 mmHg) and lipid profiles, with only slightly increased overall adverse events (RR 1.12).

Time-restricted eating versus six-meal diet study with 174 participants showed superior weight loss with time-restricted eating (1.17 kg additional loss, Cohen's d=0.42), greater BMI reduction, and improved waist-to-hip ratios, though the six-meal approach achieved better LDL reduction while more participants preferred continuing time-restricted eating.

Petrelintide's Position in the Evolving Obesity Treatment Landscape

The obesity treatment landscape has evolved significantly with recent clinical evidence demonstrating varying efficacy across pharmacological, surgical, and lifestyle interventions. Network meta-analyses and real-world studies provide comprehensive comparisons of investigational therapies against established standard-of-care treatments, revealing notable differences in weight reduction outcomes and safety profiles.

The Future Role of Petrelintide and Amylin in Obesity Management

Recent clinical trials have identified several promising combination therapy approaches for obesity management, spanning pharmacological combinations, lifestyle interventions, and integrated treatment modalities. The most advanced pharmacological combinations involve novel dual and triple hormone receptor agonists, with bimagrumab plus semaglutide demonstrating particularly robust results in a phase 2 trial of 507 adults with obesity. The high-dose combination (bimagrumab 30 mg/kg plus semaglutide 2.4 mg) achieved -17.8 kg weight loss at week 48 versus -3.3 kg with placebo, with continued improvements through week 72. This combination leverages bimagrumab's targeting of type II activin receptors to reduce fat mass while promoting muscle growth, combined with semaglutide's established GLP-1 receptor agonism.

Emerging multi-hormone receptor agonists represent another significant advancement, with retatrutide (GLP-1/GIP/glucagon triple agonist) demonstrating the greatest weight reduction versus placebo at -13.44 kg in network meta-analyses. Survodutide, a glucagon receptor and GLP-1 receptor dual agonist, showed substantial weight reduction of -10.74 kg versus placebo and is advancing to phase 3 trials. The SYNCHRONIZE-1 trial is investigating survodutide at doses up to 6.0 mg via once-weekly subcutaneous injections for 76 weeks in 725 participants. These investigational agents are expected to achieve weight loss in the 15-25% range, approaching the efficacy of bariatric surgery while maintaining favorable safety profiles, with mazdutide demonstrating the most favorable tolerability among the glucagon receptor agonist-based combinations.

Comprehensive lifestyle intervention combinations are also showing promise, particularly the plant-based intensive lifestyle intervention being evaluated in the REPAIR trial. This 52-week intervention combines a two-phase dietary approach (12-week plant-based total diet meal replacement followed by 40-week plant-based dietary pattern maintenance) with a 16-week structured exercise program and 52-week behavioral change curriculum targeting ≥15% weight loss for diabetes remission. Additionally, structured nutritional management combined with existing incretin therapies is gaining recognition, with systematic reviews indicating that energy intake decreases by 24-39% with semaglutide and tirzepatide, though lean tissue loss accounts for up to 40% of total weight reduction, emphasizing the need for mechanism-based nutritional counseling tailored to GLP-1 and dual GIP/GLP-1 receptor agonists.

Roche's Amylin Strategy: Prioritizing Tolerability in a Crowded Market

The recent Phase 2 results for Roche's amylin analog, petrelintide, present a nuanced picture in the rapidly evolving obesity treatment landscape. While the 9% placebo-controlled weight reduction at 42 weeks fell short of some analyst expectations, Roche's strategic emphasis on the drug's high tolerability—with discontinuation rates comparable to placebo—signals a deliberate pivot. This approach aims to carve out a distinct niche for petrelintide, positioning it not as a direct competitor to the high-efficacy GLP-1/GIP agonists, but rather as a valuable option for patients prioritizing fewer side effects, or for use in long-term maintenance and combination regimens.

This strategy acknowledges the diverse needs within the obesity patient population. For individuals who experience significant gastrointestinal side effects with other therapies, or those seeking a more gradual, sustainable weight management solution, petrelintide's profile could be particularly appealing. The literature indicates that while amylin analogs, including petrelintide, can cause gastrointestinal side effects similar to GLP-1R agonists, these often resolve with continued use. The development of other amylin analogs, such as the AMY1R-selective eloralintide, which has shown favorable GI tolerability, further underscores the potential for this class to offer differentiated profiles.

However, this strategic positioning is not without its challenges. The primary risk lies in the perception of efficacy; a 9% weight loss, while clinically meaningful, may be viewed as insufficient by some prescribers and patients accustomed to the higher efficacy numbers reported by leading GLP-1/GIP agonists. Furthermore, the amylin analog space itself is dynamic, with ongoing efforts to develop more potent compounds. For instance, BGM1812, a novel dual amylin and calcitonin receptor agonist (DACRA) derived from petrelintide, is being optimized for enhanced agonistic activity. The success of combination therapies, such as CagriSema (cagrilintide + semaglutide), which achieved greater effects than either component alone, also highlights the potential for petrelintide to be part of future multi-modal approaches. Ultimately, petrelintide's success may hinge on its ability to demonstrate compelling benefits in real-world settings, particularly in combination with other agents, or in specific patient segments where tolerability and long-term adherence are paramount.