Adicet's prula-cel faces systemic sclerosis test in a Phase 1 safety cohort
Adicet Bio plans a systemic sclerosis update on prula-cel by year-end, a safety and dose-finding readout in a trial with no direct competitor sharing its gamma delta CAR-T mechanism.
Executive Summary
- Adicet Bio is preparing a systemic sclerosis update for its allogeneic gamma delta CAR-T candidate, one cohort inside a broader Phase 1 trial testing the same cell therapy across several autoimmune diseases.
- The registered primary endpoints are adverse-event rates and dose-limiting toxicities, meaning the update speaks to tolerability and dosing, not a proven treatment effect.
- No other program in clinical testing shares this therapy's gamma delta CAR-T mechanism in the indications it is pursuing, leaving the systemic sclerosis cohort without a direct mechanistic comparator.
- The trial has kept its enrollment target and completion timeline stable since early 2025, and the sponsor has already disclosed a positive, though non-numeric, update from the trial's lupus cohorts.
The catalyst
Adicet Bio said in a May 13, 2026 earnings release that it plans to provide a clinical update in patients with systemic sclerosis in the second half of 2026. The disclosure sits inside a broader Phase 1 trial, NCT06375993, that is evaluating prula-cel (formerly ADI-001) across lupus nephritis, systemic lupus erythematosus, systemic sclerosis, ANCA-associated vasculitis, idiopathic inflammatory myopathies and stiff person syndrome. Chief Executive Officer Chen Schor said the company is "approaching a key inflection point" as it prepares to report Phase 1 data for prula-cel, including data from at least 20 lupus nephritis and SLE patients with a minimum of six months of follow-up, though that specific commitment applies to the lupus cohorts rather than the systemic sclerosis arm covered by this catalyst. Adicet+1Adicet Bio Reports First Quarter 2026 Financial Results and Provides Business UpdatesMay 13, 2026A Phase 1 Study of Prulacabtagene Leucel (Prula-cel, Formerly ADI-001) in Autoimmune DiseaseNCT06375993
Probability of SuccessBased on the AppliedXL Probability of Success model. For more information about the methodology, read the research here.
What the readout tests
The trial's registered primary endpoints are the proportion of treatment-emergent and treatment-related adverse events and the incidence of dose-limiting toxicities within each dose cohort. That makes this an open-label, non-randomized Phase 1 safety and dose-finding study: the systemic sclerosis update will show whether the cell therapy is tolerable and what dose level clears further testing, not whether it produces a durable disease response. The trial enrolls patients with diffuse cutaneous systemic sclerosis with worsening skin disease (a modified Rodnan skin score of 15 or higher) or with progressive interstitial lung disease, a population selected for active, treatment-refractory disease. NCT06375993A Phase 1 Study of Prulacabtagene Leucel (Prula-cel, Formerly ADI-001) in Autoimmune DiseaseNCT06375993
Prior disclosure
Adicet reported positive data from the Phase 1 prula-cel autoimmune study in its fourth-quarter and full-year 2025 results, though that release did not include numeric efficacy or safety figures. The company also said in the same May update that, following alignment with the FDA in November 2025, lupus nephritis and SLE patients in the trial may now be dosed with prula-cel in the outpatient setting, and that it intends to meet with the FDA on pivotal trial design for lupus nephritis or lupus nephritis plus SLE. Those steps apply to the lupus cohorts; the systemic sclerosis arm has not yet had a comparable update. AdicetAdicet Bio Reports First Quarter 2026 Financial Results and Provides Business UpdatesMay 13, 2026
Operational footing
The trial's enrollment target rose from 40 to 180 patients in January 2025, a change registered before the study reached its current enrollment phase and not a signal against the update. The study moved from Recruiting to Enrolling by invitation in March 2026, consistent with a trial narrowing enrollment to selected sites as cohorts fill, and its primary completion date has not moved from December 1, 2026. The protocol has logged one enrollment-count amendment and two status changes since opening in April 2024, a change frequency the trial's own registry history describes as stable. NCT06375993A Phase 1 Study of Prulacabtagene Leucel (Prula-cel, Formerly ADI-001) in Autoimmune DiseaseNCT06375993
The competitive field
No program in clinical testing shares prula-cel's gamma delta CAR-T mechanism in systemic sclerosis or the trial's other target indications. The closest modality precedent is GT801, an early Phase 1 gamma delta-adjacent cell therapy in systemic lupus erythematosus from Vivacta Biotechnology, though it targets a different antigen. The systemic sclerosis field itself includes CD19-directed CAR-T programs such as Cabaletta Bio's CABA-201 and antibody and small-molecule programs including belimumab and nerandomilast, none of which share prula-cel's mechanism. With no validated cell-therapy mechanism established in systemic sclerosis, a tolerable safety profile across dose levels with dose-limiting toxicities within the range seen in other CAR-T programs would be the finding that lets the sponsor advance the cohort toward a larger study.
This analysis was produced using AI-assisted reporting systems, AppliedXL data, and official public records. These systems undergo editorial review, quality checks, and regular audits by human experts. Errors may still occur, as with any automated system. Always consult the linked primary sources. Read our AI Editorial Policy.