This is a Phase 1 (a and b), first in human (FIH), single-arm, open-label, multicenter study to evaluate the safety, tolerability and efficacy of GCC2005 in the treatment of patients with relapsed/refractory (R/R) NK or T-cell malignancies who have received at least two prior lines of therapy.

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 patients and to provide a safety profile of GCC2005 in target patient population. Phase 1b of the study is planned to conduct dose optimization to determine the maximum tolerated dose (MTD) and recommended Phase 2 dose (RP2D).

Inclusion Criteria:

• Patients with relapsed or refractory CD5+ NK and T-cell originated malignancies (per WHO classification 2017).
• Patients with relapsed or refractory disease previously treated with two or more lines of standard chemotherapies and there is no longer any treatment option considered as assessed by the Investigator.
• According to the Lugano classification, patients having lesion/nodules ≥ 1 with diameter longer than 1.5 cm for nodal lesions and longer than 1.0 cm for extranodal lesions, and the boundaries are clearly shown.
• Patient has a performance status of 0, 1, or 2 on the Eastern Cooperative Oncology Group (ECOG) Performance Status.
• Patients who satisfy the criteria defined in the protocol.
• Contraceptive use by men and women must be consistent with local regulations regarding the methods of contraception for those participating in clinical studies.

Exclusion Criteria:

• Has T-ALL/T-LBL or CTCL.
• Patient with CNS lymphoma or any involvement of the CNS.
• Patient who had a prior history of another malignancy over the last 3 years.
• Patients who have used hematopoietic growth factor therapy within 14 days prior to Screening.
• Patients who have had prior CAR-T or CAR-NK therapies.
• Presence of uncontrolled fungal, bacterial, viral infection or other infection requiring IV antimicrobials for management
• Patients with previous allogenic organ transplantation
• Patients with previous diagnosis of primary immunodeficiency or currently undergoing therapy of primary immunodeficiency.
• Patients with acute GvHD ≥ Grade 3 or extensive chronic GvHD within 2 weeks of lymphodepletion.
• Patients with known active Hepatitis B or C
• Patients with presence of Grade 2 or greater toxicity from the previous treatment.