ADI-001 clinical development program now addresses six autoimmune diseases

Patient enrollment for idiopathic inflammatory myopathy and stiff person syndrome cohort expected to be initiated in the first quarter of 2025

Company plans to report initial clinical data from Phase 1 study in multiple autoimmune diseases in the first half of 2025

REDWOOD CITY, CA & BOSTON, MA, USA I October 16, 2024 I Adicet Bio, Inc. (Nasdaq: ACET), a clinical stage biotechnology company discovering and developing allogeneic gamma delta T cell therapies for autoimmune diseases and cancer, today announced that the U.S. Food and Drug Administration (FDA) has agreed to an amendment to the Company’s Investigational New Drug (IND) application to evaluate ADI-001 in idiopathic inflammatory myopathy (IIM) and stiff person syndrome (SPS) as part of the ongoing Phase 1 trial in autoimmune diseases. The Company plans to initiate enrollment for IIM and SPS patients in the first quarter of 2025. This announcement follows the FDA’s recent agreements on amendments to the Company’s ADI-001 IND application to evaluate three additional indications beyond lupus nephritis (LN), including systemic lupus erythematosus (SLE), systemic sclerosis (SSc) and anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV).

“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 as we aim to bring our differentiated gamma delta T cell therapy candidates to more patients in need of new treatment options,” said Chen Schor, President and Chief Executive Officer at Adicet Bio. “Following our recent announcement highlighting clinical biomarker data which demonstrated robust B-cell depletion and preferential trafficking to tissues and organs, we believe in ADI-001’s best-in-class potential for the treatment of autoimmune diseases, and we look forward to initiating patient enrollment in IIM and SPS in the first quarter of 2025 in our ongoing Phase 1 clinical program.”

The ADI-001 Phase 1 program in autoimmune diseases will have four separate arms, enrolling LN and SLE patients into one arm, SSc patients into a second arm, AAV patients into a third arm, and IIM and SPS patients into a fourth arm. The fourth cohort combines several rare autoimmune muscle diseases into a single dose-finding population, including SPS and the following IIM subtypes: 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 the follow up period on 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

Idiopathic inflammatory myopathy (IIM, or myositis) refers to 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. Five of 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 have the potential to be life threatening. There is no available cure for IIM and many patients on current treatments have refractory disease and may experience significant side effects.

About Stiff Person Syndrome

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 available cure for SPS.

About ADI-001

ADI-001 is aninvestigational allogeneic gamma delta chimeric antigen receptor (CAR) T cell therapy targeting CD20 for the treatment of autoimmune diseases. ADI-001 was granted Fast Track Designation by the FDA for the treatment of relapsed/refractory class III or class IV lupus nephritis (LN), and 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 was shown to target B-cells via an anti-CD20 CAR and demonstrated robust exposure and complete CD19+ B-cell depletion both in peripheral blood and secondary lymphoid tissue.

About Adicet Bio, Inc.

Adicet Bio, Inc. is a clinical stage biotechnology company discovering and developing allogeneic gamma delta T cell therapies for autoimmune diseases and cancer. Adicet is advancing a pipeline of “off-the-shelf” gamma delta T cells, engineered with chimeric antigen receptors (CARs), to facilitate durable activity in patients. For more information, please visit our website at https://www.adicetbio.com.

SOURCE: Adicet Bio