Ascletis announced that the U.S. FDA has approved its Investigational New Drug (IND) application for a Phase I study of ASC35, a once-monthly subcutaneously administered GLP-1R/GIPR dual agonist peptide for the treatment of obesity.

- The Phase I trial consists of two parts. Part A is a single ascending dose (SAD) study of ASC35 formulated as a Self-Assembling Lipid Depot (SALD) for once-monthly administration; Part B is a multiple ascending dose (MAD), head-to-head study comparing the ASC35 SALD once-monthly formulation against the FDA-approved weekly formulation of tirzepatide.

- In a head-to-head non-human primate study, ASC35 demonstrated an average observed half-life approximately six times longer than that of tirzepatide, supporting once-monthly subcutaneous dosing in humans.

- In a head-to-head diet-induced obesity (DIO) mouse study, ASC35 showed approximately a 71% greater weight-loss effect compared to tirzepatide.

Hong Kong, June 23, 2026 — Ascletis Pharma Limited (HKEX: 1672, 'Ascletis') today announced it has recently received U.S. Food and Drug Administration (FDA) approval for its Investigational New Drug (IND) application to initiate a Phase I study of ASC35. ASC35 is a once-monthly subcutaneously administered GLP-1 receptor (GLP-1R)/GIP receptor (GIPR) dual agonist peptide with the potential to be best-in-class, developed for the treatment of obesity.

This Phase I trial is a randomized, double-blind, placebo-controlled clinical study designed to evaluate the safety, tolerability, pharmacokinetics, and pharmacodynamics of ASC35 following single- and multiple-ascending doses in 84 subjects who are either obese (body mass index [BMI] ≥30.0 kg/m²) or overweight (BMI ≥27.0 kg/m²) with weight-related comorbidities. The Phase I trial consists of two parts: Part A is a single-ascending dose (SAD) study of ASC35’s self-assembling lipid depot (SALD) once-monthly formulation; Part B is a head-to-head, multiple-ascending dose (MAD) study comparing the ASC35 SALD once-monthly formulation against the U.S. FDA-approved weekly formulation of tirzepatide.

ASC35 was independently developed using Ascletis’ proprietary structure-based, AI-assisted drug discovery (AISBDD) technology. The ASC35 SALD once-monthly formulation was developed using Ascletis’ ultra-long-acting platform (ULAP) technology.

The SALD formulation is a low-viscosity solution composed of lipids, biocompatible organic solvents, and the active pharmaceutical ingredient (API). This low-viscosity solution can be easily injected subcutaneously using an auto-injector or injection pen fitted with a fine needle as small as 29-gauge. Following subcutaneous injection, the solution transforms into a gel-like depot within the tissue. Under the action of biological enzymes in the subcutaneous tissue, this depot degrades slowly, enabling controlled release of the API over one month or longer.

In a head-to-head non-human primate study, the mean apparent half-life of subcutaneously administered ASC35 SALD formulation was approximately six times longer than that of the FDA-approved subcutaneous formulation of tirzepatide. Compared with other incretin peptides, ASC35 demonstrated a longer apparent half-life and a flatter pharmacokinetic profile in non-human primates—advantages that may also translate into better gastrointestinal tolerability in humans.

In a head-to-head non-human primate study, systemic drug exposure following intravenous and subcutaneous administration of ASC35 was approximately 80% and 70% higher, respectively, than that observed after intravenous and subcutaneous administration of tirzepatide.

In a head-to-head diet-induced obesity (DIO) mouse study—where the DIO model has been validated as highly predictive of efficacy in humans—administration of equimolar doses of ASC35 and tirzepatide resulted in a 71% greater relative weight loss with ASC35 compared to tirzepatide.

In vitro studies showed that ASC35 exhibits approximately four-fold greater agonist activity at both GLP-1R and GIPR receptors compared to tirzepatide. Taken together with all preclinical data, ASC35 demonstrates superior efficacy on a per-milligram peptide basis relative to tirzepatide.

Dr. Jinzi J. Wu, Founder, Chairman, and CEO of Ascletis, stated:

The FDA approval to initiate clinical trials for ASC35’s once-monthly formulation, developed using our proprietary SALD platform technology, represents an exciting and significant milestone for Ascletis’ peptide pipeline targeting obesity. We are currently advancing multiple peptide candidates—designed for once-monthly to once-quarterly subcutaneous dosing—into clinical development.

ASC35’s exceptional weight-loss potential, combined with its flexible and patient-friendly once-monthly subcutaneous dosing regimen, is expected to address significant unmet needs in the rapidly growing obesity market.

About Ascletis Pharma Inc.

Ascletis Pharma Inc. is a fully integrated biotechnology company focusing on the development and commercialization of potential best-in-class and first-in-class drugs for metabolic diseases. Leveraging its proprietary Artificial Intelligence-assisted Structure-Based Drug Discovery (AISBDD), Ultra-Long-Acting Platform (ULAP) technology, and Peptide Oral Transport ENhancement Technology (POTENT), Ascletis has independently developed multiple small molecule and peptide drug candidates, including its core project ASC30, an investigational small molecule GLP-1R agonist that can be administered orally once daily or via subcutaneous injection once monthly to once quarterly as a weight loss treatment and maintenance therapy for long-term weight management; ASC36, a peptide amylin receptor agonist; ASC35, a once-monthly subcutaneous injectable GLP-1R/GIPR dual-target agonist peptide; ASC37, a GLP-1R/GIPR/GCGR triple-target agonist peptide; ASC39, a potent oral small molecule amylin receptor agonist selective for amylin, similar to eloralintide; and ASC30_39 FDC, a fixed-dose combination (FDC) of ASC30 (GLP-1RA) and ASC39 (amylin receptor agonist) for long-term weight management. Ascletis is listed on the Hong Kong Stock Exchange (1672.HK).

For more information, please visit the website:www.ascletis.com。

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