Design of a Phase 2b study evaluating the efficacy and safety of ATL1102 in non-ambulant DMD

Topic:

Clinical Trials

Poster Number: M149

Author(s):

Andrew McKenzie, PhD, Antisense Therapeutics, Haluk Topaloglu, MD, Yeditepe University, Turkey, Elif Arslan, MD, Marmara University Pendik Research and Education Hospital Turkey, Tracey Willis, MD, Robert Jones and Agnes Hunt Orthopaedic NHS Trust Hospital, UK, Ian Woodcock, MD, The Murdoch Children’s Research Institute, Australia, Coskun Yarar, MD, Osmangazi University, Turkey, Ivaylo Tarnev, MD, UMHAT Aleksandrovska Neurology clinic, Bulgaria, George Tachas, PhD, Percheron Therapeutics Limited (formerly Antisense Therapeutics), James Garner, MD, Antisense Therapeutics, Thomas Voit, MD, Great Ormond Street Institute of Child Health Biomedical Research Centre, UK

ATL1102 is an antisense oligonucleotide inhibitor of human CD49d, the alpha-chain of adhesion molecule VLA-4. ATL1102 reduced blood CD49d+ immune cells producing promising six-month Phase 2a results in non-ambulant patients with DMD; stabilizing upper limb PUL2.0 function, MRI fat fraction, and strength measurements. These findings suggest that CD49d expressing circulating T cells could be a therapeutic target to slow down disease progression in patients with DMD.
This Phase 2b study aims to assess the efficacy, safety, PK and pharmacodynamics of 2 dose levels of ATL1102 in 45 non-ambulant patients aged 10 to <18 years with DMD (NCT05938023). This study consists of two phases; a blinded treatment period of two dose levels of ATL1102 (25 mg and 50 mg) administered once weekly by SC injection over a 25 week period, compared to a placebo. This will be followed by a 24 week open label extension (OLE) treatment period of two dose levels of ATL1102 (25 mg and 50 mg) administered once weekly. Placebo patients will be re-randomized to one of the active treatment groups for the OLE. The primary endpoint will be assessed by change in the Performance of Upper Limb Module for DMD 2.0 (PUL 2.0) score compared to placebo at Week 24. Additional endpoints for assessment of muscle function, strength, respiratory function and Quality of Life will also be evaluated. The study is ongoing at multiple sites across the UK, Australia, Turkey and Bulgaria.