A Clinical Study of SCTC21C in Participants With CD38+ Hematologic Malignancies

This is a multicenter, open-label, phase I study aimed to evaluate the safety, tolerability, pharmacokinetics（PK）, Pharmacodynamics（PD）, preliminary anti-tumor activity and immunogenicity of SCTC21C in patients with relapsed or refractory CD38+ hematologic malignancies.The study includes Dose-finding stage and Dose-expansion stage. In Dose-finding stage, participants will be assigned to receive sequentially higher doses of SCTC21C ranging from 0.01 to 960mg. In Dose-expansion stage, total of at least 20 participants will be randomly assigned to receive two different doses of SCTC21C at a ratio of 1:1.All participants will receive the treatment until disease progression or unacceptable drug-related adverse events.

Inclusion criteria

• Male or female aged ≥ 18 years old when signing ICF, weight ≥ 40 kg, ≤ 90 kg
• Relapsed or refractory CD38+（confirmed by immunohistochemistry or flow cytometry） hematologic malignancies
• Standard therapies failed or are unavailable or intolerant
• Participants have at least one of the measurable lesions
• Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 2
• Life expectancy ≥3 months
• Participants with basically normal liver, kidney and heart functions
• Hematology requirements: platelet≥75x10^9 /L,absolute neutrophil counts ≥ 1.0x10^9 /L, hemoglobin ≥ 8.0 g/dL
• Women of childbearing potential (must have a negative blood pregnancy test within 7 days before the first dose) or male participants must use a highly effective method of contraception from signed ICF to 5 months after the last dose.All participants are prohibited from donating sperms or ova during the study period and 5 months after the last dose

Exclusion criteria

• A history of allergic reactions to any SCTC21C injection or any excipients, or Participants with a history of severe drug allergy
• Participants who have other antineoplastic drug (except hormones) or radiotherapy within four weeks prior to the first dose of study drug, or the participants who have received immunotherapy or anti-CD38 monoclonal antibody within 6 months
• Adverse events from the previous treatment have not resolved to ≤ Grade 1
• Participants with prior immunotherapy and Grade ≥ 3 cytokine release syndrome(CRS)
• Central nervous system involvement
• Participants with positive Human immunodeficiency virus (HIV) antibody
• HBsAg positive with HBV-DNA titer higher than the lower limit of the test value of the research center, or HCV antibody positive with HCV-RNA titer higher than the lower limit of the test value of the research center
• Active infections that require systemic treatment within 1 week prior to the first dose
• History of additional malignant tumor or active autoimmune diseases,or participants with other serious medical conditions
• Participants underwent major surgery within 4 weeks prior to the first dose, or had a surgical schedule during the study period
• History of allogeneic hematopoietic stem cell transplantation or solid organ transplantation,or history of autologous hematopoietic stem cell transplantation within 6 months prior to screening
• Participants with significant digestive system dysfunction that may affect drug intake, transport and absorption
• Participants who have received live vaccines within 30 days prior to the first dose of study drug
• Participants with mental disorders or poor compliance
• Female participants who are breastfeeding
• The Investigator determined that the participant is ineligible for the study for other reasons