Prula-cel Shows Early Promise in Lupus

Adicet Bio reports 12-month remission and renal response data for its allogeneic gamma delta CAR T therapy

October 8, 2026
3 min

The Medicine Maker

Overview

In a Phase I dataset reported by Adicet Bio, prulacabtagene leucel (prula-cel) was associated with DORIS remission in 54% of evaluable patients at 12 months and complete renal response in 50% of evaluable patients with lupus nephritis. The company reported that all efficacy-evaluable patients discontinued immunosuppressants and that safety-evaluable patients had no CRS above Grade 2; these findings are preliminary and come from a small, early-phase dataset.

Background

Systemic lupus erythematosus (SLE), including lupus nephritis, is treated with immunosuppressive therapies, and the supplied 2025 ACR guidance emphasizes hydroxychloroquine, limiting glucocorticoid exposure, and early use of conventional and/or biologic immunosuppressants to achieve remission or low disease activity. For lupus nephritis, contemporary guidance describes combination treatment and continued therapy after renal response. Prula-cel is an investigational, off-the-shelf allogeneic gamma delta CAR T therapy designed to target B cells through an anti-CD20 CAR. The reported Phase I findings address remission, renal response, treatment discontinuation, and safety in patients with SLE with or without nephritis.

Data Highlights

Measure	Reported result
Efficacy-evaluable population	22 patients: 16 with lupus nephritis and 6 with extra-renal SLE; all had at least 6 months of follow-up
Patients with at least 12 months of follow-up	13
DORIS remission at 12 months	54% of evaluable patients
Complete renal response at 12 months	50% of evaluable lupus nephritis patients
Background treatment	All efficacy-evaluable patients discontinued immunosuppressants; all but one reduced corticosteroids to ≤5 mg/day prednisone equivalent
Safety-evaluable population	24 patients
CRS	Grade 1 or 2 in 25%; no CRS above Grade 2
Other reported safety outcomes	No IEC-HS, immune effector cell-associated neurotoxicity syndrome, graft-versus-host disease, or dose-limiting toxicities
Infections	54% overall; Grade 3 or higher in 8.3%
B-cell findings	All 22 efficacy-evaluable patients had undetectable CD19-positive B cells followed by naïve-dominant B-cell reconstitution

Key Findings

The Phase I efficacy dataset included 22 patients, of whom 16 had lupus nephritis and 6 had extra-renal SLE; all had at least 6 months of follow-up.
At 12 months, 54% of evaluable patients achieved DORIS remission, and 50% of evaluable lupus nephritis patients achieved complete renal response.
All efficacy-evaluable patients discontinued immunosuppressant treatment; all but one reduced background corticosteroids to 5 mg/day or less of prednisone equivalent.
Adicet reported that responses observed at 12 months were generally maintained through 12–21 months of follow-up.
Among 24 safety-evaluable patients, Grade 1 or 2 CRS occurred in 25%; no CRS above Grade 2, IEC-HS, immune effector cell-associated neurotoxicity syndrome, graft-versus-host disease, or dose-limiting toxicities were reported. Infections occurred in 54%, including Grade 3 or higher infections in 8.3%.
All 22 efficacy-evaluable patients had undetectable CD19-positive B cells followed by naïve-dominant B-cell reconstitution. Adicet described this pattern as evidence of an “immune reset”; the company plans a single-arm pivotal study in lupus nephritis after inadequate response to at least two immunosuppressants, with start-up activities expected in Q4 2026.

Clinical Implications

The reported results are from a small Phase I dataset and do not establish comparative efficacy or safety. Current ACR guidance for SLE emphasizes hydroxychloroquine, limiting glucocorticoid exposure, and immunosuppressive treatment to achieve remission or low disease activity; the supplied lupus nephritis guidance describes combination therapy. Prula-cel remains investigational, and Adicet has described plans for a pivotal study in lupus nephritis.

Conclusion

Adicet’s Phase I report describes remission and renal-response outcomes, treatment discontinuation, and a safety profile without CRS above Grade 2 in the evaluated patients. Further study is planned to assess prula-cel in lupus nephritis.