Adicet Bio's off-the-shelf CAR-T therapy shows promise in lupus trial

Adicet Bio announced positive Phase 1 data for its off-the-shelf CAR-T therapy, prula-cel, in patients with systemic lupus erythematosus and lupus nephritis. At 12 months, 50% of evaluable kidney patients achieved a complete response and 54% reached remission, allowing all patients to stop immunosuppressants. The donor-derived gamma-delta T-cell therapy showed no severe cytokine release syndrome or neurotoxicity. Despite the promising results and analyst price target raises, Adicet Bio shares fell 22% on September 28, 2026, as the company prepares to launch a pivotal trial in late 2026.

Phase 1 trial efficacy

• ▪All 22 efficacy-evaluable patients in the Phase 1 trial of Adicet Bio's prula-cel discontinued immunosuppressants, and all but one tapered background steroids to 5 mg or less of prednisone equivalent.
• ▪In a Phase 1 trial of Adicet Bio's prula-cel, 50% of evaluable lupus nephritis patients achieved a complete renal response and 54% achieved DORIS remission at the 12-month mark.

Phase 1 trial safety

• ▪In the Phase 1 trial of Adicet Bio's prula-cel, Grade 1 or 2 cytokine release syndrome occurred in 25% of patients, while Grade 3 or higher infections occurred in 8.3% of patients.
• ▪Across 24 safety-evaluable patients treated with Adicet Bio's prula-cel, there were no cases of cytokine release syndrome greater than Grade 2, no IEC-HS, no ICANS, and no graft-versus-host disease.

Prula-cel mechanism of action

• ▪Adicet Bio's prula-cel is an off-the-shelf, allogeneic CAR-T therapy derived from donor cells that targets B-cells via an anti-CD20 CAR.
• ▪Unlike personalized alpha-beta CAR-T therapies, Adicet Bio's prula-cel utilizes gamma-delta T cells, which are designed to secrete fewer inflammatory cytokines and reduce immune-related side effects.

Future clinical plans

• ▪Adicet Bio plans to discuss with the FDA in the fourth quarter of 2026 the potential expansion of its pivotal prula-cel study to include lupus patients without nephritis.
• ▪Adicet Bio plans to initiate start-up activities for a pivotal study of prula-cel in lupus nephritis in the fourth quarter of 2026.

Stock performance

• ▪On September 28, 2026, Adicet Bio's stock was trading at $7.45 with a market cap of $77 million.
• ▪Despite the positive clinical data, Adicet Bio shares dropped 22% by mid-morning on September 28, 2026.
• ▪The market value of Adicet Bio peaked in 2022 when its gamma delta CAR-T treatment first showed promise against cancer.

Analyst stock ratings

• ▪Guggenheim adjusted its price target for Adicet Bio to $90 from $100, maintaining a Buy rating based on the company's updated spending rate and cash position.
• ▪Wedbush raised its stock price target on Adicet Bio to $28 from $25 while maintaining an Outperform rating, citing maturing clinical data for prula-cel.

Debatable claims

• ▪CAR-T therapy is ready to replace chronic immunosuppressants as the standard of care for lupus
• ▪Allogeneic CAR-T therapies are ready to replace personalized CAR-T for autoimmune diseases