A Open-Label Phase in Participants With Multiple Myeloma

Inclusion Criteria: * 1\. Aged at least 18 years old; * 2\. Initial diagnosis of multiple myeloma documented according to International Myeloma Working Group (IMWG) diagnostic criteria.Multiple myeloma is defined as clonal bone marrow plasma cells ≥ 10% or biopsy-proven bony or extramedullary plasmacytoma, and any one or more of the following myeloma-defining events: • Evidence of end-organ damage attributable to the underlying plasma cell proliferative disorder, including the following: Hypercalcemia: serum calcium \> 0.25 mmol/L (\> 1 mg/dL) above the upper limit of normal or corrected serum calcium \> 2.75 mmol/L (\> 11 mg/dL); renal insufficiency: creatinine clearance \< 40 mL/min or serum creatinine \> 177 μmol/L (\> 2 mg/dL); anemia: hemoglobin value \> 2 g/dL below the lower limit of normal or hemoglobin value \< 10 g/dL; bone lesions: one or more osteolytic lesions on skeletal radiographs, computed tomography (CT), or positron emission tomography (PET)-CT. • Any one or more of the following biomarkers of malignancy: Clonal bone marrow plasma cell percentage ≥ 60%; involved-to-uninvolved serum free light chain ratio ≥ 100 \[involved serum free light chain (FLC) level must be ≥ 100 mg/L\]; \> 1 focal lesion (at least 5 mm in size) on magnetic resonance imaging (MRI) examination. * 3.Safety run-in stage: Relapsed or refractory measurable multiple myeloma who have previously received ≥ 1 line of anti-myeloma therapy (including treatment with at least one proteasome in…