GR1803 Injection in Patients With RRMM

Single-Arm, Open, Multi-Center Phase II Clinical Trial of the Efficacy, Safety, Pharmacokinetics, and Immunogenicity of GR1803 Injection in Patients With Relapsed/Refractory Multiple Myeloma Complicated by Extramedullary Plasmacytoma

All subjects will receive GR1803 injection until intolerable toxicity or investigator-assessed disease progression occurs (except in cases of disease progression due to discontinuation of the drug as a result of an adverse event) or until the subject has been administered the drug for 2 years or until the subject withdraws consent or until the investigator determines that the subject needs to be discontinued.

Inclusion Criteria:

• 1、ECOG score 0-2 2、≥18 years of age 3、Multiple myeloma must be Complicated by Extramedullary Plasmacytoma.

Exclusion Criteria:

• 1、Prior treatment with any BCMA-targeted therapy 2、Known active CNS involvement or exhibits clinical signs of meningeal involvement of multiple myeloma 3、Known allergies, hypersensitivity, or intolerance to the study drug (teclistamab) or its excipients 4、Plasma cell leukemia , Waldenström's macroglobulinemia, POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, and skin changes), or primary amyloid light-chain amyloidosis.