Arnatar Therapeutics Announces First-in-Human Dosing of ART104 in Investigator-Initiated Trial for Alagille Syndrome

Suzhou, San Diego, California, USA, September 15, 2025 — Arnatar Therapeutics, a biotechnology company focused on developing RNA-targeted therapies to address serious diseases with unmet medical needs, today announced that the first patient has been dosed with its ART104 drug in an Investigator-Initiated Trial (IIT) on September 1, 2025, Beijing time. The patient experienced no discomfort throughout the process. The first follow-up visit after dosing has been completed, and no drug-related adverse effects were identified during the evaluation, indicating good safety. ART104 is a first-in-class antisense oligonucleotide (ASO) drug designed to treat the genetic root cause of disease.Alagille Syndrome（ALGS）。

This IIT study is led by Professor Wang JianShe from the Children's Hospital of Fudan University, a globally recognized expert in ALGS research and treatment. The study will preliminarily evaluate the safety, pharmacokinetics/pharmacodynamics (PK/PD), and efficacy of ART104 in patients with ALGS.

"The completion of the first patient dosing with ART104 is not only an important milestone for Arnatar, but also a significant advancement in the entire ALGS field," said Dr. Yanfeng Wang, Chief Operating Officer and Head of Drug Development at Arnatar Therapeutics. "By directly addressing the insufficient levels of Jag1 protein, ART104 has the potential to fundamentally change disease outcomes for ALGS patients and their families."

About ART104: The First Jag1 Protein Enhancement Strategy

ART104, based on Arnatar's proprietary ACT-UP1 technology, is the first ASO therapeutic drug aimed at upregulating Jag1 protein expression. Low levels of Jag1 protein caused by Jag1 haploinsufficiency are considered the main pathogenic cause of ALGS, a severe multisystem disease characterized by bile duct paucity and liver dysfunction.

In preclinical studies, the initial advantages of ART104 have emerged:

• Significantly Restore Liver Bile Duct Development in Disease Animal Models

• Demonstrated good tolerance in multiple toxicology studies

ART104Has obtained the approval from the U.S. Food and Drug Administration (FDA) Granted Rare Disease Drug Designation (ODD) and Pediatric Rare Disease Designation (PRDD), highlighting its potential as a transformative therapy.ART104Dedicated to changing the existing treatment standards, Arnatar Therapeutics is expected to become the first targetedALGSEffective therapeutic drugs for the root cause of the disease, achieving a leap from symptomatic treatment to disease-modifying treatment. 

ArnatarIs a clinical-stage biotechnology company dedicated to redefining RNA The Possibilities of Medicine.ArnatarWith independent research and developmentDARGER™ Technology Platform,Including optimizationsiRNA Gene Silencing Technology and First-in-Class Oligonucleotides (ASO) Up-regulation protein expression technology. This dual-technology platform enables Arnatar Able to develop different RNATargetedDrug: Can be administered either through siRNA Silent harmful pathogenic factors can also be upregulated. ASO Restore the function of key proteins, thereby opening new treatment avenues for previously untreatable diseases. The company's R&D pipeline covers cardiovascular metabolism, liver, kidney, and central nervous system diseases, targeting areas with high unmet medical needs.Arnatar By RNA Founded by leading figures in the field of treatment and supported by top biotechnology investment institutions, dedicated to advancing throughInnovativeRNA Targeted technologies, developed and transformed into life-changing, programmable drugs to benefit patients worldwide.