Inclusion Criteria:

- Adult patients; >/= 18 years of age

- Eastern Cooperative Oncology Group (ECOG) performance status 0, 1, or 2

- Relapsed or refractory multiple myeloma for which no effective standard therapy
exists

- One of the prior therapies must have included a proteosome inhibitor or an
immunomodulatory drug

- Measurable disease as defined by protocol

Exclusion Criteria:

- Prior use of monoclonal antibody within 4 weeks before Cycle 1, Day 1

- Treatment with radiotherapy, thalidomide, lenalidomide, bortezomib, any
chemotherapeutic agent, or treatment with any investigational anti-cancer agent
within 2 weeks prior to Cycle 1, Day 1

- Toxicities from any previous treatment must be resolved prior to Cycle 1, Day 1,
except for neuropathy

- Completion of autologous stem cell transplant within 100 days prior to Cycle 1, Day 1

- Prior allogeneic stem cell transplant

- History of severe allergic or anaphylactic reactions to monoclonal antibody therapy
(or recombinant antibody-related fusion proteins)

- Grade > 1 peripheral neuropathy

- Active infection at screening or any major episode of infection requiring treatment
with IV antibiotics or hospitalization within 4 weeks prior to Cycle 1, Day 1

- Positive for hepatitis B, hepatitis C or HIV infection

- Pregnant or lactating women or women who intend to become pregnant within the period
of time of this study