The following criteria is provided for health care professionals.

Inclusion Criteria:

• Signed written informed consent obtained prior to study procedures
• Histologically- or cytologically-confirmed relapsed or refractory multiple myeloma (MM) with measurable disease
• Must have received at least 3 prior lines of therapy to include treatment with a proteasome inhibitor (eg, bortezomib, carfilzomib, or ixazomib) and an immunomodulatory agent (eg, lenalidomide, pomalidomide) unless double-refractory to both; and a hematopoietic stem cell transplant (HSCT), for those subjects considered HSCT-eligible.
• Quantitative serum IgG levels for subjects with IgG MM must not exceed the institutional upper limit of normal (ULN)
• ECOG 0 or 1
• Life expectancy of at least 6 months
• Absolute neutrophil (ANC) count greater than 1000/ µL
• Platelet count greater than 50,000/µL
• Estimated GFR >30mL/min/1.73m2

Exclusion Criteria:

• Known active central nervous system (CNS) involvement by MM
• Systemic rheumatic or autoimmune diseases or acute or chronic infections
• Uncontrolled thromboembolic events or recent severe hemorrhage
• Subjects who are currently using more than 5mg/day of prednisone (or an equivalent glucocorticoid exceeding physiologic replacement levels)
• Prior treatment as follows:
  • T cell-directed antibody therapy (eg. Alemtuzumab, anti-thymocyte globulin) within 6 months of enrollment
  • Any prior myeloma-directed therapy including cytotoxic chemotherapy, biologic therapy, or radiotherapy within 2 weeks of enrollment
  • Any mAb or other protein therapeutic containing Fc-domains within 4 weeks of enrollment
  • Experimental agents within 3 half-lives prior to enrollment, unless progression is documented on therapy
  • Prior BCMA-directed investigational agents at any time
  • Prior cell or gene therapy, excluding transfers of genetically unmodified autologous cells (eg. Hematopoietic stem cell transplantation), at any time; or prior allogeneic HSCT at any time
• Pregnant or breastfeeding