Every Patient in a Small Lupus Trial Stopped Immunosuppressants

Adicet Bio says every patient in an early-stage trial of its experimental lupus treatment stopped taking immunosuppressant drugs after a single dose. The company published the trial's first full year of results for the therapy, prulacabtagene leucel, on September 28, 2026, in a release filed with the U.S. Securities and Exchange Commission. Twenty-two patients were assessed, there was no control group, and the figures are the company's own.

Systemic lupus erythematosus is a disease in which the immune system attacks the body's own tissue; in 16 of the patients it had damaged the kidneys, a form of the disease called lupus nephritis. Prula-cel, as Adicet calls it, is a CAR-T therapy, immune cells engineered to seek out a target, and the company makes it in advance from donor cells rather than growing it from each patient's own. It is experimental and is not approved anywhere.

Adicet's release reports that at 12 months, 50% of evaluable lupus nephritis patients had a complete renal response, the study's measure of kidney recovery, and 54% of evaluable patients met DORIS, a standard remission definition. Thirteen of the 22 had been followed that long, and the company does not give the number of patients behind either percentage. All but one also cut back their background steroids.

The company reports no case of cytokine release syndrome, an immune overreaction, above Grade 2. It also reports no neurological toxicity and no graft-versus-host disease, in which donated cells attack the recipient. Infections were reported in 54% of patients and were severe in 8.3%.

Adicet says the U.S. Food and Drug Administration has agreed that the pivotal trial it plans in lupus nephritis can also be single-arm, with complete renal response as its main endpoint, and that start-up work will begin in the fourth quarter of 2026.