ASCLETIS-B: The American clinical study of ASC47, a small molecule THRβ agonist for targeted fat, administered once a month in combination with semaglutide for the treatment of obesity, has completed dosing for all subjects

According to the announcement from Ascletis Pharma-B (01672), a randomized, double-blind, placebo-controlled study (ASC47-103 study, NCT06972992) has recently completed the administration of the drug to all 28 subjects, evaluating the safety, tolerability, and preliminary efficacy on day 29 of a single administration of the ultra-long-acting subcutaneous ASC47 combined with semaglutide in obese subjects without type 2 diabetes. The enrollment of 28 subjects was completed rapidly within two months. The ASC47-103 study is being conducted in the United States and consists of three cohorts, where subjects receive a single escalating dose of ASC47 (10 mg, 30 mg, and 60 mg) or an equal volume-matched placebo. Subjects in each cohort also receive four doses of semaglutide (0.5 mg, once a week). "Such rapid progress in the clinical enrollment of ASC47 highlights the industry's strong interest in new weight loss therapies and the potential advantages of combination treatments," said Dr. Eddie Wu, founder, chairman, and CEO of Ascletis Pharma. "The trial is progressing steadily as planned, and top-line data is expected to be obtained in the fourth quarter of 2025." ASC47 is a thyroid hormone receptor β (THRβ) selective small molecule agonist that is independently developed by Ascletis, designed for fat targeting and ultra-long-acting subcutaneous injection. ASC47 has unique differentiated characteristics that allow it to target fat, resulting in dose-dependent high drug concentrations in adipose tissue. In a diet-induced obesity (DIO) mouse model, ASC47 achieved higher drug concentrations in adipose tissue compared to semaglutide (63.5% vs 39.6%, p=0.007) and tirzepatide (68.0% vs 50.4%, p=0.01), leading to a greater reduction in fat with significant differences. The ASC47 monotherapy demonstrated a half-life of up to 40 days in a Phase Ib study involving obese subjects (NCT06427590). In head-to-head comparisons in the DIO mouse model, low-dose ASC47 combined with semaglutide resulted in a 56.7% greater weight loss compared to semaglutide monotherapy, without muscle loss. Top-line data from the ASC47 and semaglutide combination therapy study is expected to be obtained in the fourth quarter of 2025