The purpose of the study is to assess the safety, tolerability, and preliminary efficacy of GCC2005 in treatment of patients with relapsed or refractory NK cell and T-cell malignancies expressing CD5. Phase 1a of the study will be conducted to establish a dose range that is well tolerated by the majority of participants and to determine a safety profile of GCC2005 in participant population. Phase 1b of this study is planned to evaluate safety, PK/PD characteristics, and preliminary efficacy following single administration, reflecting the cumulative exposure level obtained with multiple administration based on the safety and tolerability assessment results confirmed in Phase 1a, and to assess dose and regimen optimization to determine the RP2D for subsequent studies.
