This is a multicenter, open-label, dose-escalation study of MFGR1877S in patients with relapsed or refractory t(4;14)-positive multiple myeloma.

Inclusion Criteria:

• ECOG performance status of 0, 1, or 2
• Life expectancy of at least 12 weeks
• Histologic documentation of previously treated t(4;14)-positive multiple myeloma for which no effective standard therapy exists

Exclusion Criteria:

• Prior use of any monoclonal antibody before study treatment
• Treatment with radiotherapy, thalidomide, lenalidomide, bortezomib, any chemotherapeutic agent, or treatment with any other investigational anti-cancer agent within 4 weeks of study treatment
• Completion of autologous stem cell transplant within 6 months prior to study treatment
• Prior allogeneic stem cell transplant
• History of severe allergic or anaphylactic reactions to monoclonal antibody therapy
• Evidence of significant, uncontrolled concomitant diseases, including significant cardiovascular disease or pulmonary disease
• Known active bacterial, viral, fungal, mycobacterial, parasitic, or other infection at screening or any recent major episode of infection requiring treatment with IV antibiotics or hospitalization prior to study treatment
• Recent major surgery (prior to study treatment), other than for diagnosis
• Presence of positive test results for Hepatitis B or Hepatitis C
• Known history of HIV seropositive status
• Women who are pregnant or lactating
• Childbearing potential without agreement to use effective form of contraception for the duration of the study