A Phase 3, Multicenter, Open-Label, Randomized Study Comparing GR1803 Injection Versus Daratumumab, Pomalidomide, and Dexamethasone (DPd) in Participants With Relapsed or Refractory Multiple Myeloma Who Have Received 1 to 3 Prior Lines of Therapy Including Lenalidomide and Proteasome Inhibitors
The purpose of this study is to compare the efficacy of GR1803 Injection with daratumumab in combination with pomalidomide and dexamethasone (DPd).
• Have an eastern cooperative oncology group (ECOG) performance status score of 0, 1, or 2 at screening and baseline.
• Diagnosed as multiple myeloma according to the diagnostic criteria of the International Myeloma Working Group (IMWG) diagnostic criteria.
• Received 1 to 3 prior line(s) of antimyeloma therapy including a proteasome inhibitor (PI) and lenalidomide; a. participants who have received only 1 line of prior line of antimyeloma therapy must be lenalidomide refractory. Stable disease or progression on or within 60 days of the last dose of lenalidomide given as maintenance will meet this criterion.
• Documented evidence of progressive or stable disease based on investigator's determination of response by IMWG criteria on or after their last regimen.
• Measurable disease at screening and baseline as defined by any of the following: 1) serum M-protein level greater than or equal to (\>=) 5 gram per liter (g/L); or 2) urine M-protein level \>=200 milligrams (mg)/24 hours; or 3) serum immunoglobulin free light chain \>=100 mg/L and abnormal serum immunoglobulin kappa lambda free light chain ratio.
• Have clinical laboratory values within the specified range.
• Have an understanding of and comply with the clinical trial protocol requirements, voluntarily participate in the clinical trial, and sign the informed consent form.