Study of YKST02 Alone or in Combination With YK012 in Patients With Active or Refractory Systemic Lupus Erythematosus

This is a single-center, open-label clinical trial evaluating YKST02 administered alone or in combination with YK012 in participants with active or refractory systemic lupus erythematosus (SLE). The study is designed to assess safety, tolerability, pharmacokinetics (PK), pharmacodynamics (PD), immunogenicity, and preliminary efficacy. The study consists of two cohorts: Cohort 1 (YKST02 Monotherapy): Participants will receive YKST02 as a single agent to evaluate its safety, tolerability, and preliminary efficacy. Cohort 2 (Combination Therapy): Participants will receive YKST02 in combination with YK012. This cohort includes a dose-escalation phase to evaluate safety and tolerability across dose levels, followed by a dose-expansion phase to further evaluate safety and preliminary efficacy at selected dose levels. The study includes a screening period, a treatment period during which participants receive study drugs by intravenous infusion, and a follow-up period for safety and efficacy assessments. Safety evaluations include monitoring of adverse events, clinical laboratory tests, and other safety parameters. PK and PD assessments will be performed to characterize drug exposure and biological activity. Immunogenicity will be evaluated by assessing anti-drug antibody responses. Exploratory analyses may include evaluation of immune cell populations, cytokines, and other biomarkers to further characterize the biological effects of the study treatments.