Study of ATX-01 in Participants With DM1 (ArthemiR)

A Phase 1/2a Double-Blind, Placebo-controlled, Single- and Multiple Ascending Dose Study to Assess the Safety, Tolerability, PK, PD and Efficacy of IV Administration of ATX-01 In Male and Female Participants Aged 18 to 64 With Classic DM1

The goal of this clinical trial is to test ATX-01 in participants with myotonic dystrophy type 1 (DM1). The main question it aims to answer is if ATX-01 is safe and well tolerated. The trial will compare the safety and tolerability of ATX-01 and a matching placebo.

There will be a single-ascending dose part of the trial and a multiple-ascending dose part. In the single-ascending dose, participants will receive one dose of ATX-01 or placebo. In the multiple-ascending dose part, participants will receive three doses of ATX-01 or placebo.

ATX-01 is a novel anti-miR (synthetic single stranded oligonucleotide) that inhibits a microRNA called miR-23b.

Study Overview

• Status: Not yet recruiting
• Conditions: Myotonic Dystrophy 1
• Intervention / Treatment: Drug: Placebo; Drug: ATX-01

• Study Type: Interventional
• Enrollment (Estimated): 56
• Phase: Phase 2; Phase 1

Contacts and Locations

• Study Contact: Name: Project Manager; Phone Number: +34676229821; Email: clinical@arthexbiotech.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

Key Inclusion Criteria:

• Participants with a documented clinical diagnosis of DM1 (CTG expansion of >150 repeats in DMPK gene measured in peripheral blood mononuclear cells)
• Ambulatory, defined as able to complete a 10-meter walk/run test at screening without the use of assistive devices such as canes, walkers, or orthoses, except for ankle-foot orthoses
• Presence for >3 seconds of grip myotonia as confirmed by a central reader

Key Exclusion Criteria:

• Participants with congenital DM1
• Medical Research Council Muscle Scale score of less than 4 on ankle dorsiflexion or significant tibialis anterior atrophy that prevents a muscle biopsy
• Use of mexiletine or other agent for within 21 days or 5 half-lives, whichever is longer, prior to screening

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: ATX-01; ATX-01 is a formulation of the anti-microRNA 23b (anti-miR-23b), known as X82108, a novel type of antisense oligonucleotide	Drug: ATX-01; Solution for infusion
Placebo Comparator: Placebo; Placebo to ATX-01	Drug: Placebo; Solution for infusion

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of adverse events	To evaluate the safety and tolerability of ATX-01 in adult participants with DM1	Up to 120 days

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of clinically significant changes in laboratory assessments, electrocardiograms (ECGs), vital signs, suicidal ideation and behavior	To further evaluate the safety and tolerability of ATX-01 in adult participants with DM1	Up to 120 days
Maximum observed plasma concentration (Cmax) of ATX-01		Up to 48 hours post-dose
Area under the plasma concentration-time curve (AUC) of ATX-01		Up to 48 hours post-dose
Video hand opening time	To evaluate the efficacy of ATX-01 on myotonia in participants with DM1	Change from baseline up to 120 days
Change from baseline in ankle dorsiflexion strength by quantitative myometry	To evaluate the effects of ATX-01 in participants with DM1 on ankle dorsiflexion strength	Change from baseline up to 120 days
Change from baseline in Impact on Activities of Daily Living questionnaire item scores	The Impact on Activities of Daily Living questionnaire is a 7-item patient-reported outcome designed to evaluate the impact of ATX-01 on activities of daily living in participants with DM1.	Change from baseline up to 120 days

Collaborators and Investigators

• Sponsor: ARTHEx Biotech S.L.

Study record dates

Study Major Dates

• Study Start (Estimated): May 1, 2024
• Primary Completion (Estimated): December 1, 2025
• Study Completion (Estimated): December 1, 2025

Study Registration Dates

• First Submitted: February 26, 2024
• First Submitted That Met QC Criteria: March 2, 2024
• First Posted (Actual): March 8, 2024

Study Record Updates

• Last Update Posted (Actual): March 8, 2024
• Last Update Submitted That Met QC Criteria: March 2, 2024
• Last Verified: March 1, 2024

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Nervous System Diseases; Genetic Diseases, Inborn; Musculoskeletal Diseases; Muscular Diseases; Neuromuscular Diseases; Neurodegenerative Diseases; Muscular Disorders, Atrophic; Heredodegenerative Disorders, Nervous System; Muscular Dystrophies; Myotonic Disorders; Myotonic Dystrophy
• Other Study ID Numbers: CT-ATX-01-DM1-1.1

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No