Ultralow-Dose Interleukin 10–Expressing Chimeric Antigen Receptor T Cells in Relapsed/Refractory Diffuse Large B-Cell Lymphoma

Importance: Interleukin (IL)-10 expressing CD19 chimeric antigen receptor (CAR) T cells (META 10-19) have demonstrated encouraging clinical activity in B-cell acute lymphoblastic leukemia, but their safety and efficacy in relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL) remain unknown. Objective: To evaluate the safety and efficacy of META 10-19 in patients with R/R DLBCL. Design, Setting, and Participants: This nonrandomized, phase 1 clinical trial was conducted at the First Affiliated Hospital of Zhejiang University School of Medicine. Patients were enrolled from November 16, 2023, to April 7, 2025. The data cutoff date was January 20, 2026. The data analysis was conducted on January 22, 2026. Twenty patients were screened, and 13 received a META 10-19 infusion. The median duration of follow-up was 15.6 (range, 0.7-25.5) months. Intervention: Following lymphodepletion with fludarabine and cyclophosphamide, patients received META 10-19 at dose levels of 2 × 103, 5 × 103 or 2 × 104 CAR T cells/kg. Main Outcomes and Measures: The primary end points were adverse events, dose-limiting toxic effects, and objective response rate. The secondary end points included complete remission (CR) and a cellular kinetic of META 10-19. Results: Among 13 treated patients (median age, 61 years [range, 35-74 years]; 8 men [61.5%] and 5 women [38.5%]), the objective response rate was 92.3%, including CR in 11 patients (84.6%) and partial remission in 1 patient (7.7%). One patient died before response assessment because of disease-related gastrointestinal complications. Cytokine release syndrome occurred for 12 patients (grade 1: n = 8; grade 2: n = 3; grade 3: n = 1), and immune effector cell-associated neurotoxicity syndrome occurred for 2 patients (grade 1: n = 1; grade 2: n = 1). Robust in vivo CAR T-cell expansion was observed across dose levels, with a median (range) peak expansion of 660.7 (30.7-10 562.3) cells/µL. At data cutoff, 5 patients experienced a maintained CR and 7 experienced disease relapses or progression (2 with CD19 negative relapses). Conclusions and Relevance: The results of this nonrandomized clinical trial suggest that ultralow-dose META 10-19 demonstrated promising antitumor activity and a manageable safety profile in patients with R/R DLBCL. Further investigation in larger cohorts is warranted. Trial Registration: ClinicalTrials.gov Identifier: NCT06120166.