Clinical Research of Pomalidomide Maintenance Therapy for Primary Multiple Myeloma

Inclusion Criteria: 1. Subject diagnosed as initially diagnosed with symptomatic MM by the diagnostic criteria of International Myeloma Working Group(IMWG), aged ≥ 18 years. 2. Subject undergoing ASCT who have had prior induction therapy for no more than 12 months and whose disease has not progressed within 3 months of ASCT. 3. Subject who are not candidates for ASCT have reached maximum efficacy after induction and consolidation therapy. 4. Eastern Cooperative Oncology Group (ECOG) physical status score of 0-3. 5. Serum transaminase levels less than three times the upper limit of normal, serum total bilirubin levels not exceeding 35 umol/L, serum creatinine levels less than 177 umol/L, absolute neutrophil values greater than 1.0 x 10\^9/L, and platelet counts greater than 75 x 10\^9/L. 6. Subject of childbearing potential must use two reliable methods of contraception simultaneously or have absolutely no sexual relations with the opposite sex for 4 weeks prior to initiation of treatment, during treatment, during suspension of dosing and for 4 weeks after termination of treatment, and women of childbearing potential agree to perform monthly pregnancy tests until 4 weeks after discontinuation of study drug. 7. Subject voluntarily enrolled in this study and signed an informed consent form. Exclusion Criteria: 1. Subject has 17p-, 1q21 amplification, t(4;14), t(14;16), t(14;20), t(11;14), and p53 mutation. 2. Subject who, in the judgment of the investigator, cannot tolerate pomalidomide treatment or are allergic to lenalidomide or thalidomide drugs. 3. Subject with a diagnosis of nonsecretory MM (meaning subjects with completely nonsecretory MM or subjects with a small amount of free light chain but with less than 100 mg/L of affected light chain). 4. with central nervous system involvement. 5. subject with peripheral neuropathy ≥ grade 3. 6. subject with known active hepatitis B virus (HBV-DNA ≥ l × 103 copies/mL or HBV-DNA \> 200 IU/mL) or hepatitis C virus (HCV), or serologically positive for human immunodeficiency virus (HIV). 7. Subject with concurrent other neoplasms or a prior history of neoplasms or antineoplastic therapy (including major surgery) within the last 4 weeks, except for the following neoplastic diseases or those who have lived tumor-free for ≥ 3 years to date: basal cell carcinoma of the skin, squamous epithelial cell carcinoma of the skin, carcinoma in situ of the cervix, carcinoma in situ of the breast, incidental histologic findings of prostate cancer (TNM clinical stage of T1a or T1b) or treated prostate cancer. 8. Subject with coexisting serious infectious disease. 9. Subject who refuse to use a reliable form of contraception during pregnancy and lactation or at an appropriate age. 10. Subject with active new thrombosis or unwilling to undergo antithrombotic therapy. 11. Subject who, in the opinion of the investigator, are not suitable for enrollment.