• Phase I trial consists of two parts. Part A is a single ascending dose (SAD) study of ASC35 once-monthly Self-Assembling Lipid Depot (SALD) formulation; Part B is a head-to-head study of multiple ascending doses (MAD) of ASC35 once-monthly SALD formulation compared to the U.S. Food and Drug Administration (FDA)-authorized tirzepatide once-weekly formulation.
• In head-to-head non-human primate (NHP) studies, the average observed half-life of ASC35 was approximately six-fold longer than tirzepatide, which supports once-monthly subcutaneous (SQ) dosing in humans.
• In a head-to-head diet-induced obese (DIO) mouse study, ASC35 demonstrated approximately 71% greater relative body weight reduction compared to tirzepatide.

HONG KONG, June 23, 2026 /PRNewswire/ -- Ascletis Pharma Inc. (HKEX: 1672, "Ascletis") announces today that it recently received Investigational New Drug (IND) clearance from the U.S. Food and Drug Administration (FDA) for the Phase I study of ASC35, a potentially best-in-class, once-monthly subcutaneously administered GLP-1 receptor (GLP-1R)/GIP receptor (GIPR) dual peptide agonist, for the treatment of obesity.

The Phase I trial is a randomized, double-blind, placebo-controlled clinical trial designed to evaluate the safety, tolerability, pharmacokinetics, and pharmacodynamics of ASC35 following single and multiple ascending doses in 84 participants with obesity (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 once-monthly Self-Assembling Lipid Depot (SALD) formulation; Part B is a head-to-head study of multiple ascending doses (MAD) of ASC35 once-monthly SALD formulation compared to the U.S. FDA-approved tirzepatide once-weekly formulation.

ASC35 was discovered and developed in-house utilizing Ascletis' Artificial Intelligence-Assisted Structure-Based Drug Discovery (AISBDD) technology.  ASC35 once-monthly SALD formulation was developed utilizing Ascletis' Ultra-Long-Acting Platform (ULAP) technology.

SALD formulation is a low-viscosity solution which is composed of lipids, biocompatible organic solvents, and the active pharmaceutical ingredient (API). The low-viscosity solution can be easily administered into the subcutaneous tissue using an injection pen/auto-injector with a fine needle as thin as 29 gauge. After subcutaneous (SQ) administration, the solution transforms into a gel-like depot in the tissue. Under the action of enzymes in the tissue, the depot slowly degrades, releasing the API over a one-month or longer period.

In head-to-head non-human primate (NHP) studies, ASC35 SALD formulation with SQ administration exhibited an average observed half-life of approximately six-fold longer than tirzepatide in its FDA-authorized SQ formulation. The longer observed half-life and a flatter pharmacokinetic profile of ASC35 in NHPs compared to other peptide incretins may also translate into a better gastrointestinal tolerability in humans.  

In head-to-head NHP studies, drug exposures of ASC35 intravenous (I.V.) and SQ administration were approximately 80% and 70% greater than tirzepatide I.V. and SQ administration, respectively.

In a head-to-head diet-induced obese (DIO) mouse study, which is well established as being highly predictive of human efficacy, dosed with equal molar concentrations of ASC35 and tirzepatide, ASC35 demonstrated a relative greater efficacy of 71% compared to tirzepatide. 

ASC35 was approximately four-fold more potent than tirzepatide for both GLP-1R and GIPR in vitro. Combination of all preclinical studies suggests ASC35 is more efficient on a per-milligram peptide basis compared to tirzepatide.

"The FDA's IND clearance for ASC35 once-monthly utilizing our proprietary SALD formulation is an exciting and significant milestone for Ascletis' peptide pipeline to treat obesity as we advance multiple once-monthly to once-quarterly SQ administered peptides into the clinic," said Jinzi Jason Wu, Ph.D., Founder, Chairman and CEO of Ascletis, "ASC35's potential for superior weight loss combined with a more versatile and patient-friendly once-monthly SQ injection will address a major unmet need in the rapidly growing obesity market."

About Ascletis Pharma Inc.

Ascletis Pharma Inc. is a fully integrated biotechnology company focused on the development and commercialization of potential best-in-class and first-in-class therapeutics to treat metabolic diseases. Utilizing its proprietary Artificial Intelligence-assisted Structure-Based Drug Discovery (AISBDD) and Ultra-Long-Acting Platform (ULAP) technologies as well as Peptide Oral Transport ENhancement Technology (POTENT), Ascletis has developed multiple drug candidates in-house, including both small molecules and peptides, such as its lead program, ASC30, a small molecule GLP-1R agonist designed to be administered once daily orally and once monthly to once quarterly subcutaneously as a treatment therapy and a maintenance therapy for chronic weight management; ASC36, an amylin receptor peptide agonist, ASC35, a once-monthly subcutaneously administered GLP-1R/GIPR dual peptide agonist and ASC37, a GLP-1R/GIPR/GCGR triple peptide agonist, ASC39, an eloralintide-like potent and amylin-selective oral small molecule amylin receptor agonist, and ASC30_39 FDC, a fixed-dose combination (FDC) of ASC30 (GLP-1RA) and ASC39 (amylin RA), for chronic weight management. Ascletis is listed on the Hong Kong Stock Exchange (1672.HK).

For more information, please visit www.ascletis.com.

Contact：
Peter Vozzo
ICR Healthcare
443-231-0505 (U.S.)
Peter.vozzo@icrhealthcare.com 

Ascletis Pharma Inc. PR and IR Teams
+86-181-0650-9129 (China)
pr@ascletis.com
ir@ascletis.com