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.
Plasma cell leukemia, Waldenström's macroglobulinemia, POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, M-protein, and skin changes), or amyloidosis (including primary and secondary).
History or clinical signs of central nervous system involvement or meningeal involvement of multiple myeloma .
Received any prior B cell maturation antigen (BCMA)-directed therapy.
Has disease that is considered refractory or intolerant to an anti-cluster of differentiation 38 (CD38) targeted therapy or Pomalidomide.