Adicet Bio, Inc. (Nasdaq: ACET) has received FDA clearance for an amendment to its Investigational New Drug (IND) application, allowing the evaluation of ADI-001 in idiopathic inflammatory myopathy (IIM) and stiff person syndrome (SPS) within its ongoing Phase 1 trial for autoimmune diseases. The company plans to initiate patient enrollment for the IIM and SPS cohort in the first quarter of 2025.
This follows previous FDA agreements on amendments to the ADI-001 IND application to include systemic lupus erythematosus (SLE), systemic sclerosis (SSc), and anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV), in addition to lupus nephritis (LN).
Expanding ADI-001's Clinical Scope
"The FDA’s acceptance of our IND amendment to evaluate ADI-001 in patients with IIM and SPS builds on our recent momentum in autoimmune diseases, expanding our efforts to six autoimmune indications," said Chen Schor, President and Chief Executive Officer at Adicet Bio. The company aims to bring its differentiated gamma delta T cell therapy candidates to more patients in need of new treatment options.
Adicet Bio believes in ADI-001’s potential for treating autoimmune diseases, citing clinical biomarker data demonstrating robust B-cell depletion and preferential trafficking to tissues and organs. The company anticipates initiating patient enrollment for IIM and SPS in the first quarter of 2025 as part of its ongoing Phase 1 clinical program.
Phase 1 Trial Design
The ADI-001 Phase 1 program in autoimmune diseases will consist of four arms. The first arm will enroll LN and SLE patients, the second SSc patients, the third AAV patients, and the fourth IIM and SPS patients. The fourth cohort combines several rare autoimmune muscle diseases, including SPS and IIM subtypes such as dermatomyositis, anti-synthetase syndrome, immune-mediated necrotizing myopathy, polymyositis, and overlap myositis. Enrolled patients will receive a single dose of ADI-001.
The dose-limiting toxicity window is 28 days, with response and safety assessments conducted on Day 28 and during follow-up periods at months 3, 6, 9, 12, 18, and 24. The primary objectives of the study are to evaluate the safety and tolerability of ADI-001. Secondary objectives include measuring cellular kinetics, pharmacodynamics, changes in autoantibody titers, and appropriate disease activity scores in each indication.
About Idiopathic Inflammatory Myopathy (IIM)
Idiopathic inflammatory myopathy (IIM), also known as myositis, encompasses a group of rare autoimmune disorders characterized by chronic muscle inflammation and progressive muscle weakness. IIM primarily affects skeletal muscles but can also involve other organs such as the lungs, heart, and skin. The main subtypes include dermatomyositis, anti-synthetase syndrome, immune-mediated necrotizing myopathy, polymyositis, and overlap myositis, all of which can lead to significant functional impairment and can be life-threatening. Currently, there is no cure for IIM, and many patients on existing treatments experience refractory disease and significant side effects.
About Stiff Person Syndrome (SPS)
Stiff person syndrome (SPS) is a rare neurological autoimmune disorder characterized by severe muscle stiffness and spasms, primarily affecting the torso and limbs. Muscle stiffness caused by SPS often impairs mobility, making it difficult for patients to walk, bend, or perform daily activities. Muscle spasms can be triggered by sudden stimuli such as loud noises, physical contact, or emotional distress, and can result in a "statue-like" posture when severe. Due to its rarity and overlapping symptoms with other conditions, SPS is frequently misdiagnosed, often as an anxiety disorder or movement disorder. There is currently no cure for SPS.
About ADI-001
ADI-001 is an investigational allogeneic gamma delta chimeric antigen receptor (CAR) T cell therapy targeting CD20 for the treatment of autoimmune diseases. ADI-001 has been granted Fast Track Designation by the FDA for the treatment of relapsed/refractory class III or class IV lupus nephritis (LN). The ongoing Phase 1 study is also evaluating ADI-001 for the treatment of systemic lupus erythematosus (SLE), systemic sclerosis (SSc), anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV), idiopathic inflammatory myopathy (IIM, or myositis), and stiff person syndrome (SPS). In the Phase 1 GLEAN trial, ADI-001 targeted B-cells via an anti-CD20 CAR and demonstrated robust exposure and complete CD19+ B-cell depletion in both peripheral blood and secondary lymphoid tissue.
