Chinese pharmaceutical company Ascletis Pharma Inc (HKEX: 1672) announced on Monday that that all 28 participants have been dosed in the randomised, double-blind, placebo-controlled study evaluating the safety, tolerability and preliminary efficacy at Day 29 of single-dose, ultra-long-acting subcutaneously (SQ) administered ASC47 in combination with semaglutide in participants with obesity who do not have type 2 diabetes.

Conducted in the United States, the study consists of three cohorts with single ascending doses (10 mg, 30 mg and 60 mg) of ASC47 or volume-matched placebo. Participants in each cohort also receive four doses of semaglutide (0.5 mg, once weekly).

ASC47 is an adipose-targeted, ultra-long-acting SQ injected thyroid hormone receptor beta (THR beta) selective small molecule agonist, discovered and developed in-house at Ascletis. According to the company, ASC47 possesses unique and differentiated properties to enable adipose targeting, resulting in dose-dependent high drug concentrations in the adipose tissue. As demonstrated in diet-induced obese (DIO) mouse model, high drug concentrations of ASC47 in the adipose tissue reduced significantly more fat mass than semaglutide (63.5% vs 39.6% p=0.007) and tirzepatide (68.0% vs 50.4%, p=0.01). ASC47 monotherapy demonstrated a half-life of up to 40 days in a Phase Ib study in participants with obesity. In a head-to-head DIO mouse model, low dose ASC47 in combination with semaglutide demonstrated a 56.7% greater reduction in body weight with muscle preservation compared to semaglutide monotherapy.

Topline data from this combination study of ASC47 with semaglutide are expected in the fourth quarter of 2025.