CLL-1-Targeted In Vivo CAR-T Cell Immunotherapy for Relapsed/Refractory Acute Myeloid Leukemia

This is a single-center, open-label, single-arm, phase 1 dose-escalation study to evaluate the safety, tolerability, preliminary efficacy, and cellular kinetics of SL1CC Injection, an in vivo CAR-T therapy targeting CLL-1, in patients with relapsed or refractory acute myeloid leukemia (R/R AML; acute promyelocytic leukemia excluded). SL1CC Injection is administered as a single intravenous infusion without lymphodepleting conditioning. Dose escalation follows a traditional 3+3 design with planned dose levels of 1 × 10\^9, 3 × 10\^9, and 6 × 10\^9 transducing units (TU), guided by the occurrence of dose-limiting toxicities (DLTs). Treatment-emergent adverse events and serious adverse events, including cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS), hematologic toxicity, organ toxicity, and other immune therapy-related toxicities, will be assessed. Preliminary antitumor activity, assessed by composite complete remission (CR/CRi) and measurable residual disease (MRD) status according to the European LeukemiaNet (ELN) 2022 criteria, and the expansion and persistence of CAR-T cells in peripheral blood will also be evaluated.