First-in-human data with investigational formulation of SYNT-101 establish preliminary safety, tolerability and efficacy markers, including modulation of hunger hormones
Preclinical weight loss data demonstrate 100% preservation of lean muscle mass and significant reduction in weight and caloric consumption
Findings support company’s plan for submission of a U.S. IND application in H2 2025
BOSTON, April 10, 2025 – Syntis Bio, Inc. (Syntis), a clinical-stage biopharmaceutical company revolutionizing oral therapies for obesity, diabetes and rare diseases, today announced positive preclinical and first-in-human data for its lead candidate, SYNT-101, an investigational once-daily oral treatment for obesity. The data are being presented today during two scientific sessions at the European Congress on Obesity and Weight Management (Obesity 2025) in Barcelona.
SYNT-101 is designed to induce metabolic changes that support improved glycemic control, weight loss and energy balance by redirecting nutrient absorption from the proximal to distal small intestine, creating a similar effect to gastric bypass. In preclinical rodent models, SYNT-101 produced consistent 1% weekly weight loss over the six-week study period while preserving 100% of lean muscle mass. In a first-in-human pilot study, an investigational formulation of SYNT-101 demonstrated strong evidence of nutrient redirection and resulting satiety hormone modulation. Importantly, SYNT-101 displayed strong safety and tolerability across both studies, with no adverse events reported.
“These data further validate the potential of SYNT-101 as a convenient once-daily oral alternative or complement to GLP-1 drugs, which often involve substantial costs, severe side effects such as muscle loss and long-term maintenance issues despite high efficacy rates,” said Rahul Dhanda, chief executive officer of Syntis. “With SYNT-101, we believe we can deliver sustainable, safe, effective weight loss by reducing fat while preserving lean muscle and stimulating natural production of satiety hormones, including GLP-1, to prevent weight regain. We are excited to replicate and expand upon these promising data in our upcoming Phase 1 clinical trial.”
Obesity 2025 Data Presentations
The first presentation, “SYNT-101 first-in-human evaluation of a novel pharmacologic therapeutic to replicate gastric bypass for management of obesity,” summarizes data from a nine-person safety and tolerability study of the drug at three dose levels. No treatment-related adverse events were reported, and all biopsy samples showed normal tissue histology. Glucose tolerance testing confirmed effective nutrient diversion, with no changes in safety biomarkers and complete clearance within 24 hours. Additionally, participants demonstrated favorable acute postprandial shifts in appetite-regulating hormones, including increased leptin and decreased ghrelin, consistent with enhanced satiety signaling and metabolic regulation.
The company also discussed data from a six-week study of diet-induced obesity rodent models in a second presentation, “Preclinical evaluation of SYNT-101: effects on glycemic control, weight loss, and body composition in obese rodents.” Following daily dosing and compared to control rodents, the test subjects experienced a total average weight loss of 6.1% (1% per week), 10% reduction in caloric consumption and 8% decrease in fasting glucose levels. Notably, lean muscle mass was fully preserved throughout the study, and no adverse events were observed.
“The safety profile that SYNT-101 has shown to date, coupled with these data demonstrating preservation of lean muscle mass, is remarkable and an important advance in today’s obesity treatment landscape,” commented Louis Aronne, M.D., obesity expert, past president of The Obesity Society, and member of the Syntis clinical advisory board. “A major pitfall of current GLP-1 drugs is related to the gastrointestinal side effects as well as the loss of lean muscle that accompanies weight loss. Based on these data, SYNT-101’s mechanism of action may avoid these issues entirely, which could provide both an alternative and adjunct for the millions of people living with obesity.”
About SYNT-101
SYNT-101 is being developed as a once-daily pill for the treatment of obesity. It works by transiently blocking nutrient absorption in the duodenum, the upper part of the small intestine, and redirecting nutrients to the distal small intestine to stimulate the natural secretion of satiety and metabolism-regulating hormones, including GLP-1. This mechanism, known as duodenal nutrient exclusion, is a key contributor to the efficacy of gastric bypass surgery, which remains the gold standard for weight loss and metabolic disease management. SYNT-101 leverages the power of SYNT™ (SYNthetic Tissue-lining), an oral formulation that establishes a safe, transient polymer coating to the duodenum. Syntis plans to submit an investigational new drug (IND) application to the U.S. FDA in H2 2025.
About Syntis Bio
Syntis Bio is a clinical-stage biopharmaceutical company developing oral therapies that harness the small intestine’s unique biology to provide more accessible, effective and sustainable solutions across the healthcare spectrum, from rare genetic disorders to the world’s most prevalent conditions. Syntis is rapidly advancing a pipeline of oral therapies engineered for targeted activity in the small intestine, the body’s nexus for metabolic control, digestion and drug absorption. Alongside its lead obesity program, SYNT-101, the company is advancing a portfolio of therapies targeting orphan metabolic diseases and intestinal-related disorders. Syntis is headquartered in Boston, MA. For more information, please visit www.syntis.bio and follow on LinkedIn.
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