The purpose of this study is to evaluate if the addition of SCTC21C to bortezomib, lenalidomide and dexamethasone (VRd) in patients with newly diagnosed multiple myeloma not eligible for transplant will prolong progression-free survival (PFS) and/or improve overall minimal residual disease (MRD) negativity rate compared with VRd alone.
Newly diagnosed multiple myeloma (IMWG criteria) not eligible for transplant.
Evidence of measurable disease.
With adequate organ function and hematological parameters.
Contraception，and during the study period and for 5 months after the last dose, all subjects must not donate reproductive cells.
Other hematologic malignancies.
Subjects with confirmed or suspected central nervous system infiltration or meningeal involvement.
Uncontrolled infection.
Subjects with conditions that may affect safety or efficacy assessments include, but are not limited to, cardiovascular, respiratory, endocrine/metabolic, immune system, hepatic, gastrointestinal (such as gastrointestinal bleeding, perforation, ulcers, etc.), and malignant neoplasms, and are deemed clinically significant by the investigator.