Boston — Syntis Bio reported results from the 28-day multiple ascending dose portion of its Phase 1/1b SYNTIETY-1 clinical trial evaluating SYNT-101, an oral drug candidate for obesity.
The randomized, double-blind, placebo-controlled study included 23 overweight or obese adults across three ascending dose cohorts ranging from 857 mg to 2,571 mg, equivalent to one to three tablets.
Syntis said SYNT-101 was well tolerated at all dose levels, with no treatment discontinuations or dose reductions. Gastrointestinal adverse events occurred at similar rates among participants receiving SYNT-101 and placebo.
Exploratory pharmacodynamic assessments showed increases in the satiety hormones GLP-1 and PYY and a reduction in ghrelin, a hormone associated with hunger. The company said the hormonal response was consistent with changes observed after gastric bypass surgery.
Participants receiving SYNT-101 also lost more weight than those receiving placebo across all three dose cohorts, according to the company.
“SYNT-101 was designed to produce a specific multi-hormone signature, one that mimics the metabolic response of bariatric surgery but via a once-daily oral tablet,” said David Rosenbaum, Ph.D., Chief Development Officer of Syntis Bio. “Results from the 28-day MAD portion of the SYNTIETY-1 trial confirms the mechanism initially demonstrated in the SAD arm. The continued demonstration of tolerability across all dose cohorts, together with encouraging efficacy signals, reinforce the potential of a therapy that, unlike GLP-1s and other obesity drug candidates, is specifically designed to avoid systemic circulation. Overall, these data mark a significant de-risking milestone for SYNT-101 and provide a strong foundation for its advancement into Phase 2.”
The company plans to present detailed results at The Obesity Society’s ObesityWeek 2026 meeting in Washington, D.C., in November and expects to begin a Phase 2 study in 2027.
SYNT-101 is designed to act locally in the small intestine by temporarily reducing nutrient absorption in the proximal small intestine and redirecting nutrients farther down the digestive tract. Syntis said the mechanism is intended to stimulate the body’s natural secretion of multiple satiety and metabolism-related hormones.
“By acting locally in the gut and forming a transient lining in the duodenum, SYNT-101 takes a fundamentally different approach,” said Rahul Dhanda, Chief Executive Officer of Syntis Bio.
Dhanda said the company believes the drug’s mechanism could offer another weight-management option for patients who cannot tolerate existing therapies and could potentially be studied in combination with GLP-1 drugs.
