Gamma delta CAR T-cells are being tested to ‘reset’ AAV immune system
First patient dosed in Adicet Bio’s Phase 1 trial
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The first participant with ANCA-associated vasculitis (AAV) has been dosed in a Phase 1 clinical trial testing prulacabtagene leucel (prula-cel, formerly ADI-001), Adicet Bio’s experimental CAR T-cell therapy, in people with autoimmune diseases.
All seven disease groups in the Phase 1 trial (NCT06375993) are now actively enrolling participants at two sites in the U.S. Recruitment of AAV patients started in the second half of last year. Adicet expects to provide its next clinical update in the first half of the year, with additional updates planned for the second half.
“Heading into 2026, we are proud of the strong execution across our pipeline. Since reporting data in October from our prula-cel Phase 1 program in autoimmune diseases, enrollment has more than doubled with over 20 patients as of December 31, 2025,” Chen Schor, president and CEO of Adicet Bio, said in a company press release announcing the latest corporate updates. “Taken together, these accomplishments set the stage for a meaningful data readout expected in the first half of 2026.”
In autoimmune diseases, the immune system makes antibodies that mistakenly attack healthy tissues. In AAV, these self-reactive antibodies target proteins in neutrophils, a type of immune cell, over-activating them and ultimately causing inflammation and damage to the cells that line the small blood vessels. This can damage organs such as the kidneys, lungs, and nerves.
What is Prula-cel?
Prula-cel is a CAR T-cell therapy that’s designed to kill B-cells, the immune cells that produce these harmful antibodies. The treatment starts by collecting a patient’s immune T-cells, which are then modified to produce a chimeric antigen receptor (CAR) protein that binds to CD20, a protein at the surface of B-cells.
The modified cells are then infused back into the patient, where their binding to CD20 directs them to attack and eliminate B-cells, This should lower harmful antibody levels and help relieve disease symptoms.
Most of the T-cells in prula-cel are gamma delta T-cells, a subtype found in many tissues. This localization makes them a compelling therapeutic candidate for autoimmune conditions that target and damage specific areas, including small blood vessels.
The ongoing Phase 1 trial is testing the therapy in people with one of seven autoimmune conditions: AAV, systemic lupus erythematosus (SLE; the most common form of lupus), lupus nephritis (a common complication of lupus), systemic sclerosis, idiopathic inflammatory myopathy, stiff person syndrome, and treatment-refractory rheumatoid arthritis.
Before receiving prula-cel, the participants will receive chemotherapy with fludarabine or cyclophosphamide to temporarily deplete existing immune cells and make room for the CAR T-cells, which are then delivered as a single infusion.
The study is primarily designed to evaluate the safety and tolerability of prula-cel over the first 28 days, known as the dose-limiting toxicity window, and during a follow-up of up to two years. Researchers will also monitor how the therapy behaves in the body and its impact on levels of harmful antibodies and disease activity scores for each disease.
In the first part of the study, increasing dose levels of the therapy will be given to identify the safest dose. Once it’s identified, more patients will receive the same dose to confirm its safety and to set the recommended dose for future clinical trials.
Adicet reported early trial results in October from participants with lupus nephritis and SLE that showed reductions in disease activity and improvements in kidney function, along with a favorable safety profile.
