CM336 Plus Daratumumab and Lenalidomide in Transplant-Ineligible Newly Diagnosed Multiple Myeloma

The goal of this clinical trial is to evaluate whether CM336, a BCMA/CD3 bispecific antibody, in combination with daratumumab and lenalidomide can induce deep and durable responses in adults with transplant-ineligible newly diagnosed multiple myeloma (NDMM). The study will also evaluate the safety of this treatment combination. The main questions it aims to answer are: * How many participants achieve minimal residual disease (MRD) negativity after 6 treatment cycles? * What side effects occur during treatment with CM336 combined with daratumumab and lenalidomide? * How many participants respond to treatment and how deep are these responses? * How long does MRD negativity and treatment response last? * How long do participants remain free from disease progression? All participants will receive the study treatment. There is no comparison group in this study. Participants will: * Receive CM336 by subcutaneous injection together with subcutaneous daratumumab and oral lenalidomide in 28-day treatment cycles. * Undergo regular blood tests, bone marrow examinations, MRD assessments, and disease assessments to monitor treatment response and safety. * Be monitored throughout the study for treatment-related adverse events.

Inclusion Criteria: 1. Able to understand and voluntarily sign a written informed consent form (ICF). 2. Age 18 to 75 years. 3. Newly diagnosed symptomatic multiple myeloma according to International Myeloma Working Group (IMWG) criteria. Patients who have received no more than two cycle of anti-myeloma therapy before enrollment are eligible. 4. Not planned to undergo autologous stem cell transplantation as first-line treatment and meeting at least one of the following criteria, including but not limited to: * Age ≥65 years; * Eastern Cooperative Oncology Group (ECOG) performance status of 3-4; * Considered unable to tolerate autologous stem cell transplantation based on investigator assessment. 5. Measurable disease, defined by at least one of the following: * Serum M-protein ≥10 g/L by serum protein electrophoresis (SPEP); for IgA or IgD myeloma, quantitative IgA or IgD levels may be used instead; * Urine M-protein ≥200 mg/24 hours; * If neither serum nor urine M-protein meets the above criteria, involved serum free light chain (FLC) ≥100 mg/L with an abnormal serum FLC ratio (normal range: 0.26-1.65). 6. Adequate hepatic function, defined as: * Total bilirubin \