First SSc patient dosed in Phase 1 trial of CAR T-cell therapy

Study to enroll up to 180 adults with scleroderma, other autoimmune diseases
by Andrea Lobo, PhD | July 29, 2025

The first patient with systemic sclerosis (SSc) has been dosed in a Phase 1 trial of Adicet Bio’s investigational CAR T-cell therapy for autoimmune conditions, called ADI-001, the company has announced.

Recruitment in the open-label trial (NCT06375993) is ongoing at one site in California. It’s expected to enroll up to 180 adults, ages 18-80, with SSc or other autoimmune diseases that include ANCA-associated vasculitis, idiopathic inflammatory myopathy, stiff-person syndrome, systemic lupus erythematosus, and lupus nephritis, a common complication of lupus. Preliminary results are expected in the second half of the year.

“There remains a critical unmet need for safe and effective treatment options to combat debilitating autoimmune diseases, including SSc, for which we believe ADI-001 has the potential to offer transformative benefits,” Julie Maltzman, MD, chief medical officer at Adicet Bio, said in a company press release. “We are pleased with the continued momentum of our Phase 1 trial of ADI-001 in autoimmune diseases as we announce the dosing of the first SSc patient, a key development milestone for Adicet.”
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SSc is caused by an overactive immune system that leads to inflammation and the accumulation of scar tissue, or fibrosis, in the skin and internal organs, including the heart, kidneys, lungs, and digestive tract. Like other autoimmune conditions, SSc is marked by the production of self-reactive antibodies by immune B-cells that attack healthy tissue.

What is ADI-101?
ADI-001 involves collecting a patient’s immune T-cells and modifying them to produce a chimeric antigen receptor, or CAR, that binds to CD20, a protein on the surface of B-cells.

Modified T-cells are then infused back into the patient, after a chemotherapy cycle with fludarabine and cyclophosphamide to deplete T-cells and make room for the modified ones. The cells should bind to B-cells and destroy them, reducing the production of self-reactive antibodies and easing symptoms.

The Phase 1 trial will test single increasing doses of ADI-001 in adults with diffuse or limited SSc for up to six years. Diffuse SSc typically causes more extensive skin fibrosis and is associated with a higher risk of internal organ involvement than limited SSc, a milder form of the disease.

The main goal is to assess the treatment’s safety and tolerability. Dose-limiting toxicity will be determined over 28 days at each dose level, with adverse events assessed for up to two years. The data will help determine the maximum tolerated dose, meaning the highest one that doesn’t cause unacceptable side effects. These results are needed to set a recommended dose for Phase 2 testing.
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Secondary goals include looking at ADI-001’s pharmacodynamics, or its effects in the body, as well as its efficacy at reducing self-reactive antibodies and changes in disease activity scores.