Inclusion Criteria:

- Have relapsed or refractory MM treated with at least 1 prior regimen. Prior therapy
with bortezomib is allowed if there was previously at least a minimal response (MR).

- Have measurable disease as defined by one or more of the following:

- serum M-protein concentration ≥ 1 g/dL (10 g/L)

- urine monoclonal light chain concentration ≥ 200 mg/24 hours as determined by
urine protein electrophoresis

- involved serum free light chain (SFLC) concentration ≥ 10 mg/dL (100 mg/L) and
an abnormal SFLC ratio

- Have adequate organ function including:

- Absolute neutrophil count (ANC) ≥ 1000/microliter

- Platelet (PLT) count ≥ 75,000/microliter

- Hemoglobin (Hgb) ≥ 8.0 g/dL

- Total bilirubin ≤ 1.5 x upper limit of normal (ULN) (if total is elevated check
direct and, if normal, patient is eligible)

- Aspartate transaminase (AST) and alanine aminotransferase (ALT) are ≤ 3 x ULN

- Serum creatinine ≤ 3.0 mg/dL.

- Have an Eastern Cooperative Oncology Group performance status (ECOG PS) score of ≤ 2.

- Have discontinued all previous therapies for cancer, including chemotherapy, surgery,
and radiotherapy for at least 2 weeks (6 weeks for mitomycin-C or nitrosoureas)
before study enrollment and recovered from the acute effects of therapy.

- Males and females with reproductive potential: Must agree to use medically approved
contraceptive precautions during the study and for 4 months following the last dose
of study drug.

- Females with childbearing potential: Must have had a negative urine or serum
pregnancy test <7 days before the first dose of study drug.

- Have an estimated life expectancy of ≥16 weeks, in the opinion of the investigator.

Exclusion Criteria:

- Have received treatment within 30 days of the initial dose of study drug with an
experimental agent for non-cancer indications that has not received regulatory
approval for any indication.

- Have one or more serious preexisting medical conditions that, in the opinion of the
investigator, would preclude participation in this study.

- Have an uncontrolled infection.

- Females who are pregnant or breastfeeding.

- Have known positive test results for human immunodeficiency virus (HIV), hepatitis
B*, or hepatitis C antibodies (HCAb).

* Have evidence of or test positive for hepatitis B. A positive test for hepatitis B
is defined as:

1. positive for hepatitis B surface antigen (HBsAg+). OR

2. positive for anti-hepatitis B core antibody and positive for hepatitis B
deoxyribonucleic acid (HBV DNA).

OR

3. positive for anti-hepatitis B surface antibody (HBsAb+) and positive for
hepatitis B deoxyribonucleic acid (HBV DNA).

- Have ≥ Grade 2 peripheral neuropathy or any grade with pain as assessed using the
Common Terminology Criteria for Adverse Events, version 4.03 (CTCAE v 4.03).

- Have previously received an allogenic hematopoietic stem cell transplant.

- Have previously received treatment with an experimental agent that targets B-cell
activating factor (BAFF).

- Have a corrected QT (QTc) interval >470 msec on their baseline electrocardiogram
(ECG).

- Have interstitial pneumonitis (interstitial pneumonia) or pulmonary fibrosis
manifested as opacity on chest X-ray or computed tomography (CT) scan.

- Have had another active malignancy within the past 5 years.