Arnatar Therapeutics Receives China NMPA Clearance to Initiate First-in-Human Study of ART5, a First-in-Class Up-Regulating ASO Designed to Restore Polycystin-1 for the Treatment of ADPKD

• ART5 is designed to address the most common root cause of ADPKD by targeting PKD1, potentially restoring PC1 production in approximately 85% of patients
• First-in-human SAD study in healthy volunteers expected to initiate Q3 2026
• Phase 1b study in patients with ADPKD planned for the first half of 2027
• ADPKD affects an estimated 12 million people worldwide; approximately 50% develop end-stage kidney disease
  

SAN DIEGO and SUZHOU, China, July 07, 2026 (GLOBE NEWSWIRE) -- Arnatar Therapeutics, a biotechnology company pioneering RNA-based therapies for severe and underserved diseases, today announced that the Center for Drug Evaluation (CDE) of China’s National Medical Products Administration (NMPA) has cleared the Company’s clinical trial application for ART5, a first-in-class up-regulating antisense oligonucleotide (ASO) therapeutic candidate for the treatment of autosomal dominant polycystic kidney disease (ADPKD). The first-in-human study is expected to initiate in Q3 2026.

ADPKD is driven by mutations in the PKD1 or PKD2 gene, resulting in insufficient production of polycystin proteins that normally regulate kidney cell growth and fluid balance. Loss of polycystin-1 (PC1) function drives uncontrolled cyst development, progressive kidney enlargement, and irreversible loss of kidney function. ART5, developed through Arnatar’s proprietary ACT-UP1 platform, is designed to restore endogenous PC1 production directly at the source, correcting the underlying protein insufficiency that conventional gene-silencing approaches cannot address.

“The initiation of our first-in-human study of ART5 represents a pivotal milestone for Arnatar and our mission to develop a potentially best-in-disease therapy for ADPKD,” said Xuehai Liang, Chief Executive Officer of Arnatar Therapeutics. “By restoring PKD1 expression to address the underlying cause of the disease, rather than treating its downstream consequences, we believe ART5 has the potential to become a truly disease-modifying therapy. We are excited to advance a program that we believe could redefine the standard of care for patients living with ADPKD.”

ADPKD is one of the most common inherited kidney diseases, occurring in approximately 1 in 400 to 1 in 1,000 individuals and affecting an estimated 500,000 people in the United States alone. The disease is characterized by the progressive development of fluid-filled cysts in the kidneys and in some patients, other organs, leading to chronic pain, hypertension, cardiovascular disease, and progressive loss of kidney function; approximately 50% of patients develop end-stage kidney disease requiring dialysis or kidney transplantation. The only FDA-approved treatment, tolvaptan, carries a boxed warning for serious liver toxicity, and no approved therapy targets the root cause of the disease.

In preclinical studies, ART5 demonstrated up to a two-fold increase in PC1 expression across human, mouse, and non-human primate (NHP) cells with no detectable off-target effects. In ADPKD patient-derived cells, PC1 upregulation was associated with reduced cAMP levels, decreased cyst formation, and lower cell proliferation, functional hallmarks of disease modification. In vivo, subcutaneous dosing produced durable increases in kidney PC1 protein in mice and NHPs, supporting the potential for convenient monthly or less frequent administration.

The planned first-in-human Phase 1 study is a randomized, double-blind, placebo-controlled, single ascending dose (SAD) study designed to evaluate the safety, tolerability, pharmacokinetics, and pharmacodynamic activity of a single subcutaneous dose of ART5 in healthy volunteers.

“This clearance further supports our ACT-UP1 platform and marks an important step toward expanding its application across haploinsufficiency diseases, where no adequate treatments exist. We look forward to the first clinical data for ART5 and advancing a potential new treatment option for patients with ADPKD,” added Dr. Liang.

About Arnatar Therapeutics

Arnatar Therapeutics is a clinical-stage biotechnology company redefining the possibilities of RNA medicine. With its proprietary DARGER™ platform, Arnatar uniquely integrates best-in-class siRNA gene silencing with first-in-class ACT-UP1 antisense oligonucleotides (ASOs) that upregulate protein expression. This dual-modality platform empowers Arnatar to develop RNA medicines that either silence harmful disease drivers through siRNA or restore essential protein function through up-regulating ASOs, opening new therapeutic possibilities for previously untreatable conditions. The Company’s pipeline spans cardiometabolic, liver, kidney, and central nervous system diseases, targeting areas of high unmet medical need. Founded by leaders in RNA therapeutics and backed by leading biotech investors, Arnatar is committed to transforming RNA innovation into life-changing, programmable medicines for patients worldwide. For more information, please visit www.arnatar.com.

Contacts

Jason Shieh
Business Development
bd_partnering@arnatar.com

Chris Nardo
LifeSci Advisors, LLC
cnardo@lifesciadvisors.com

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