-ATX-01 is the industry’s first microRNA therapeutic to be evaluated for DM1 and the first program from ARTHEX’s pipeline to enter the clinic –

-First patient expected to be enrolled in Q2 2024-

VALENCIA, Spain I February 28, 2024 I ARTHEx Biotech S.L., a clinical-stage biotechnology company focused on developing innovative medicines through the modulation of microRNAs, announced that the U.S. Food and Drug Administration (FDA) cleared the Company to initiate the Phase I-IIa ArthemiR™ study of ATX-01 for the treatment of Myotonic Dystrophy Type 1 (DM1). 

ATX-01, an antimiR designed to target microRNA 23b (miR-23b), is the first microRNA therapeutic to be investigated for DM1 and is the first therapeutic from ARTHEx’s pipeline to enter the clinic. miR-23b is known to be associated with regulating the expression of MBNL proteins involved in the pathogenesis of DM1, a devastating, rare neuromuscular disorder that causes muscle weakness and other life-limiting complications. There are currently no disease-modifying treatments for DM1.

“Receiving FDA clearance to initiate our first-in-human study, ArthemiR™, for ATX-01 in DM1 is a major milestone for ARTHEX and for DM1 patients and their families who are in need of an approved therapeutic option,” said Dr. Judith Walker, Chief Medical Officer of Arthex. “ATX-01 holds significant potential to deliver therapeutic benefit to DM1 patients, based on its dual mechanism of action that targets both the toxic DMPK mRNA and the reduced active MBNL levels. We plan to launch the ArthemiR™ study first in the US, followed by Canada and Europe.”

The ArthemiR™ trial is a Phase I-IIa double-blind, placebo-controlled, dose escalation study expected to enroll participants with classic Myotonic Dystrophy Type 1 (DM1). The primary objective is to determine the safety and tolerability of single and multiple ascending doses of ATX-01 in DM1 participants. ARTHEx will also investigate target engagement at the muscle level through biomarkers, including MBNL levels and splicing index. In addition, the clinical endpoints from the trial will include measures related to muscle function, patient-reported outcomes, and quality of life measures. 

Dr. Nicholas Johnson, Professor, Vice Chair of Research in the Department of Neurology at Virginia Commonwealth University, and the lead investigator for the ArthemiR™ trial, commented, “It is exciting to see new agents coming to clinical trials, especially compounds with different mechanisms of action. This increases our hope of one day having effective and safe, disease modifying treatments for this multisystemic condition. Patients are eager for new trials, and we are delighted to start enrolment in the coming months.”

About ATX-01

ATX-01 is an antimiR oligonucleotide designed to target microRNA 23b (miR-23b), which is associated with regulating the expression of MBNL proteins involved in the pathogenesis of DM1. It has been demonstrated in human DM1 myoblast cell lines that ATX-01 has a unique, dual mechanism of action which reduces toxic DMPK mRNA and increases MBNL protein levels. Toxic DMPK and reduced levels of MBNL have been identified as the molecular underpinnings of DM1. ATX-01 will shortly be evaluated in the Phase I-IIa ArthemiR™ trial for the treatment of DM1. ATX-01 has received Orphan Drug Designation for ATX-01 in DM1 from the US and European authorities. 

ATX-01 was discovered through ARTHEx’s in-house discovery engine, which is designed to identify and optimize novel microRNA modulators and ensure their preferential delivery to target tissues, for the treatment of diseases in which microRNAs are involved in the disease pathogenesis.

About Myotonic Dystrophy Type 1 (DM1)

Myotonic dystrophy type 1 (DM1) is a highly disabling disease affecting more than one million people worldwide. The condition affects muscles and other tissues (causing respiratory problems, fatigue, hypersomnia, cardiac abnormalities, severe gastrointestinal complications, and cognitive and behavioral impairment). Most commonly, it manifests during adulthood (classic DM1), although DM1 can develop at birth in a congenital form, or during childhood. Although signs and symptoms vary among affected individuals, sadly, with progression of the disease, DM1 patients experience a reduction in the ability to perform activities of daily living. Moreover, patients have a significantly shortened lifespan and there is currently no approved treatment to slow the progression of the disease.

About ARTHEx Biotech

ARTHEx Biotech is a clinical-stage biotechnology company focused on developing innovative medicines through the modulation of microRNAs. The Company’s lead investigational compound, ATX-01, is being evaluated for the treatment of myotonic dystrophy type 1 (DM1), a rare neuromuscular disorder, in the Phase I-IIa ArthemiR™ trial. ARTHEx is also advancing its in-house discovery engine to identify and develop microRNA modulators for other disorders with high unmet medical needs, including genetically-driven diseases like DM1. The Company headquarters are in Valencia, Spain.

For more information, please visit www.arthexbiotech.com and engage with us on LinkedIn.