Adicet Bio reports positive lupus data for prula-cel, plans pivotal trial start-up in Q4 2026

Adicet Bio announced on September 28, 2026 positive safety and efficacy data from a Phase 1 study evaluating prulacabtagene leucel (prula-cel, formerly ADI-001) in patients with systemic lupus erythematosus with or without lupus nephritis.¹ The data cutoff was August 28, 2026, and included 22 efficacy evaluable patients, 16 with lupus nephritis and 6 with extra-renal SLE, all with at least 6 months of follow-up and 13 patients with at least 12 months of follow-up.¹

On efficacy, at the 12-month mark, 50% of evaluable lupus nephritis patients achieved a complete renal response and 54% of evaluable patients achieved DORIS remission.¹ All 12-month responses were ongoing at 12 to 21 months of follow-up, except one patient with a urine protein-to-creatinine ratio of 0.65 g/g who remained off immunosuppressants.¹ Reductions in mean SLEDAI-2K and Physician's Global Assessment scores were rapid and sustained, and 85% of patients with 12-month follow-up achieved a PGA score below 0.5.¹

On safety, across 24 safety-evaluable patients, there was no cytokine release syndrome greater than Grade 2, with Grade 1 or 2 CRS occurring in 25% of patients.¹ There were no dose-limiting toxicities, no IEC-HS, and no ICANS; infections occurred in 54% of patients with Grade 3 or higher in 8.3%; and there were no cases of graft versus host disease.¹

All patients discontinued immunosuppressants, and all but one tapered background steroids to 5 mg or less of prednisone equivalent.¹

On regulatory plans, Adicet approached the FDA and aligned on a single-arm pivotal study in lupus nephritis patients with inadequate response to at least two immunosuppressants, expected to enroll a double-digit number of patients with complete renal response at 12 months as the primary endpoint.¹ The company plans to initiate start-up activities for the pivotal LN study in the fourth quarter of 2026.¹ The high DORIS remission rate may support expanding the pivotal study to include lupus patients without nephritis, a matter Adicet plans to discuss with the FDA in the fourth quarter of 2026.¹

Additional anticipated milestones include a clinical data update in systemic sclerosis in the first half of 2027 and a clinical data update in LN/SLE by mid-2027.¹