A Study to Evaluate the Safety and Efficacy of SCTC21C in Combination With Bortezomib, Lenalidomide and Dexamethasone in Patients With Newly Diagnosed Multiple Myeloma Not Eligible for Transplant

Who May Qualify: - Newly diagnosed multiple myeloma (IMWG criteria) not eligible for transplant. - Evidence of measurable disease. - With your organs (liver, kidneys, etc.) are working well enough based on blood tests and hematological parameters. - Contraception，and during the study period and for 5 months after the last dose, all subjects must not donate reproductive cells. Who Should NOT Join This Trial: - 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. - Subjects who have undergone major surgery or experienced significant trauma within 4 weeks prior to the first use of the investigational drug, or who require elective surgery during the trial period. - Received a live or attenuated vaccine within 30 days prior to the first dose; Female subjects who are currently breastfeeding. - Subjects with mental disorders or poor compliance, or other circumstances deemed unsuitable for participation in this study by other investigators. Always talk to your doctor about whether this trial is right for you.