New Drug AT7687 Boosts Weight Loss Beyond Leading Obesity Treatment in Early Trials
Antag Therapeutics' AT7687 showed strong safety and enhanced weight loss in Phase 1 trials, with a Phase 2a study launching mid-2026.
Summary
A new experimental drug called AT7687, developed by Antag Therapeutics, showed promising safety and early effectiveness in a Phase 1 trial involving 102 participants. The drug was well tolerated with no serious side effects and minimal gastrointestinal issues. When combined with cagrilintide — an existing obesity drug — AT7687 helped obese, insulin-resistant primates lose 12.2% of body weight compared to 7.8% with cagrilintide alone, while also improving insulin sensitivity. The drug is designed for once-weekly injection. Antag has secured €80 million in funding and plans to begin a Phase 2a human trial in mid-2026. For those tracking obesity and metabolic health science, this represents a potentially meaningful addition to the growing toolkit of weight-loss therapeutics.
Detailed Summary
Obesity and metabolic disease remain among the biggest threats to healthspan and longevity. The emergence of effective anti-obesity drugs like GLP-1 agonists has transformed the field, but researchers are still searching for combination approaches that can push weight loss further while improving metabolic markers. AT7687, developed by Antag Therapeutics, is a new candidate aiming to do exactly that.
In a randomized, placebo-controlled Phase 1 trial of 102 healthy volunteers — including people with and without obesity — AT7687 demonstrated a clean safety profile. There were no severe or serious adverse events, and gastrointestinal side effects, often a key concern with obesity drugs, were mild and evenly distributed between the drug and placebo groups. Pharmacokinetic data showed consistent, dose-proportional drug exposure with low variability, supporting a convenient once-weekly subcutaneous dosing schedule.
Perhaps the most compelling data came from preclinical studies in obese, insulin-resistant non-human primates. When AT7687 was combined with cagrilintide — an amylin analogue already in clinical development — animals lost 12.2% of body weight over 42 days, compared to 7.8% with cagrilintide alone. Crucially, insulin sensitivity improved and total energy intake was similar between groups, suggesting the additional weight loss wasn't simply from eating less but may involve distinct metabolic mechanisms.
Target engagement was confirmed at all dose levels and across multiple organ systems, suggesting the drug is hitting its intended biological pathways. Antag has raised €80 million in Series A financing to support further development and plans to initiate a Phase 2a human trial in mid-2026.
Caveats apply: this is early-stage data, and primate results don't always translate to humans. Phase 2a results will be critical for validating the weight loss and metabolic benefits seen so far. Still, the safety signal and combination potential make AT7687 a drug worth watching closely.
Key Findings
- AT7687 combined with cagrilintide produced 12.2% body weight loss in primates vs 7.8% with cagrilintide alone
- Phase 1 trial in 102 humans showed no severe adverse events and minimal GI side effects
- Drug demonstrated consistent once-weekly dosing pharmacokinetics with low inter-subject variability
- Improved insulin sensitivity observed in obese, insulin-resistant primates alongside weight loss
- Phase 2a human trial planned for mid-2026, backed by €80 million Series A funding
Methodology
This is a news report summarizing company-presented data at the American Diabetes Association 2026 Scientific Sessions. Evidence basis includes a Phase 1 randomized placebo-controlled trial and preclinical non-human primate studies; data comes from Antag Therapeutics' own disclosures and has not yet been peer-reviewed.
Study Limitations
All data presented is company-reported and not yet peer-reviewed, warranting caution. Primate weight loss results may not replicate in humans, and Phase 2a efficacy and safety data will be essential before drawing firm conclusions. Long-term effects on weight maintenance and metabolic health remain unknown.
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