Isa-VRdlite for of Frail and/or Much Older Patients With High Risk Newly Diagnosed Multiple Myeloma Base on Circulating Plasma Cells

Inclusion Criteria: * Aged ≥ 18 years with newly diagnosed symptomatic multiple myeloma who have not received any prior anti-myeloma therapy. * Confirmed positive circulating abnormal plasma cells (CPCs) in peripheral blood via flow cytometry (CPCs ≥ 0.07%). * Deemed ineligible for autologous hematopoietic stem cell transplantation due to advanced age, poor physical performance, or underlying comorbidities precluding transplant tolerance. * Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 3. * Estimated life expectancy of at least 6 months. * Adequate baseline function of major vital organs to tolerate treatment; no absolute contraindications on complete blood count, liver and renal function, cardiac enzymes or coagulation profile. * Voluntarily participate in this study, provide written informed consent, and be available for regular follow-up visits. Exclusion Criteria: * Diagnosis of primary plasma cell leukemia, solitary plasmacytoma, smoldering multiple myeloma or secondary multiple myeloma. * Prior exposure to any anti-myeloma agents, radiotherapy, or stem cell transplantation. * Concurrent other malignant tumors (except for in situ carcinoma cured for more than 5 years). * Severe active infection, active autoimmune disease, or severe cardiovascular and cerebrovascular diseases (NYHA class III-IV heart failure, recent myocardial infarction or cerebral infarction). * Known hypersensitivity to isatuximab, bortezomib, lenalidomide, dexamethas…