Inclusion Criteria:

1. Male or female subjects 18 years and older

2. Relapsed or refractory multiple myeloma defined as failure of at least 2 previous
therapies

3. Presence of serum M-protein ≥ 0.5 g per 100 mL (≥ 5 g/L) and / or urine M-protein ≥
200 mg/24-h period and / or serum FLCs ≥ 10 mg/100 mL (≥ 100 mg/L) combined with an
abnormal ratio of lambda and kappa chains

4. ANC ≥ 1.0 (1,000 / mm3) and platelets ≥ 80x10E9/L

5. Haemoglobin ≥ 8 g/dL

6. Ability to comply with all study related procedures, medication use and evaluations

Exclusion Criteria:

1. Primary refractory multiple myeloma

2. History of significant cerebrovascular disease or sensory or motor neuropathy of
toxicity grade 3 or higher

3. Treatment with systemic investigational agent within 28 days prior screening visit

4. Solitary plasmocytoma or plasma cell leukaemia

5. Previous allogenic SCT

6. Prior therapy with other monoclonal antibodies targeting the CD38 antigen and prior
therapy with other IgG monoclonal antibodies within 3 months prior to screening and
IgM monoclonal antibodies within 1 month prior to screening visit

7. Active systemic infection

8. Systemic disease preventing study treatment

9. Multiple myeloma with CNS involvement

10. Active treatment / chemotherapy for other primary malignancy within past 3 years

11. Significant uncontrolled cardiovascular disease or cardiac insufficiency