ARTHEx Raises $46 Million to Advance its Novel Treatment for Myotonic Dystrophy Type 1

Rare Daily Staff

Spain-based ARTHEx Biotech, a clinical-stage company focused on developing innovative medicines through the modulation of microRNAs, raised $46 million (€42 million) in a series B financing round.

Columbus Venture Partners led the financing, with participation from new investors European Innovation Council (EIC) fund, Hadean Ventures, and Sound Bioventures. Existing investors Invivo Capital, AdBio Partners, and the Centre for the Development of Industrial Technology (CDTI) through its Innvierte program, also participated in the financing.

The proceeds will be used to advance the company’s lead compound, ATX-01, an antimiR designed to target microRNA 23b (miR-23b), to a phase 1/2a clinical trial for the treatment of myotonic dystrophy type 1 (DM1).  miR-23b is known to be associated with regulating the expression of MBNL protein 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, which affects at least 40,000 people in the United States and 70,000 in Europe.

In connection with the financing, ARTHEx’ present Chairman of the Board of Directors, Frédéric Legros, has been appointed chief executive officer.

“This will be a pivotal year as we prepare to initiate our Phase 1/2a ArthemiR study of lead compound ATX-01 for DM1, in the second half of 2023,” said Legros.  “We believe that the market opportunity for a novel DM1 therapy is very attractive, given the limited number of companies in the clinic and the lack of an approved therapeutic agent.”

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, 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.

It has been demonstrated in human DM1 myoblast cell lines that ATX-01 has a unique, dual mechanism of action which targets toxic DMPK and MBNL proteins.  Toxic DMPK and reduced levels of MBNL have been identified as the genetic cause of DM1. In December 2022, ARTHEx announced the achievement of key regulatory milestones for the ATX-01 development program, including receiving Orphan Drug designation for ATX-01 in DM1 from both the U.S. and European authorities.

Photo: Frédéric Legros, chairman and CEO of ARTHEx