This is a randomized, double-blind, parallel-controlled, multicenter, phase III study to compare the efficacy and safety of HLX15-IV in combination with Rd (HLX15-IV-Rd) versus DARZALEX® in combination with Rd (D-Rd) in patients with NDMM who are ineligible for autologous stem cell transplantation (ASCT).

Inclusion Criteria:

1. Capable to understand and sign the ICF.
2. Patients aged ≥ 18 years .
3. Patient must have documented multiple myeloma (MM) satisfying the International Myeloma Working Group (IMWG) diagnostic criteria for MM.
4. Newly diagnosed, untreated and not considered candidate for autologous stem cell transplantation (ASCT).
5. Patient must have an ECOG performance status score of 0.
6. Patient must have pretreatment clinical laboratory values.
7. Contraceptive use by men or women should be consistent with local regulations.
8. A WOCBP must have a negative serum pregnancy test at screening within 72 hours prior to randomization.

Exclusion Criteria:

1. Patient has a diagnosis of primary amyloidosis, monoclonal gammopathy of undetermined significance (MGUS), smoldering multiple myeloma (SMM), Waldenström's disease, or other conditions in which IgM M-protein is present in the absence of a clonal plasma cell infiltration with lytic bone lesions.
2. Patient has plasma cell leukemia or POEMS syndrome .
3. Patient has prior or current systemic therapy or ASCT for MM before randomization.
4. Patient has peripheral neuropathy or neuropathic pain Grade 2 or higher.
5. Patient has a history of malignancy (other than MM) within 3 years before randomization .
6. Patient has clinical signs of meningeal involvement of MM.
7. Patient has known COPD, persistent asthma, or a history of asthma within the last 2 years.
8. Patient is known to be seropositive for history of human immunodeficiency virus (HIV) or known to have treponema pallidum antibodies (Anti-TP).
9. Patient is known to have active hepatitis B or C.
10. Patient has any concurrent medical or psychiatric condition or disease that is likely to interfere with the study procedures or results.
11. Patient has clinically significant cardiac disease.
12. Patient has known allergies, hypersensitivity, or intolerance to treatment drugs.
13. Patient has history of drug abuse or substance abuse.
14. Patient is a woman who is pregnant, or breast-feeding, or planning to become pregnant or donate eggs (ova, oocytes).
15. Patient had radiation therapy within 14 days of randomization.
16. Patient had plasmapheresis within 28 days of randomization.
17. Patient had major surgery within 28 days before randomization.
18. Patient in clinical trials of any other drug or device within 3 months before randomization.
19. Patient has any condition could prevent, limit, or confound the protocol-specified assessments.