Primary Objective:

To determine if Multi Myeloma (MM) patients mobilized with granulocyte colony-stimulating factor (G-CSF) plus plerixafor 240 μg/kg are more likely to achieve a target number of greater than or equal to 6 x 10^6 cluster of differentiation (CD) 34+ cells/kg in 2 or fewer days of apheresis than MM patients mobilized with G-CSF alone.

Secondary Objectives:

• To evaluate the safety of G-CSF plus plerixafor arm compared to G-CSF arm in MM patients.
• To compare the 2 treatment arms with respect to the number of participants who achieved a minimum of 2 x 10^6 CD34+ cells/kg in 4 or fewer days of apheresis.
• To compare the 2 treatment arms with respect to the number of days of apheresis required to reach the target of greater than or equal to 6 x 10^6 CD34+ cells/kg.

Total study duration for a participant can be approximately up to 68 days.

Inclusion criteria:

• Age 20 to 75.
• Japanese participants with histological or pathological diagnosis of MM.
• First or second complete response (CR) or partial response (PR).

Exclusion criteria:

• Leukemia participants.
• Myelodysplastic syndrome (MDS) participants.
• Less than 2 weeks since completion of last cycle of chemotherapy.
• Failed previous hematopoietic stem cell (HSC) collections or collection attempts.
• Prior autologous or allogeneic transplant.
• Diagnosis of another malignancy.
• Known hypersensitivity to plerixafor, G-CSF or their components.
• Bone marrow involvement greater than 10%.
• Eastern Cooperative Oncology Group (ECOG) performance status greater than 1.
• Not yet recovered from all acute toxic effects of prior Chemotherapy.
• White blood cell (WBC) count less than or equal to 2.5 × 10^9 cells/L.
• Absolute neutrophil count (ANC) less than or equal to 1.5 × 10^9 cells /L.
• Platelet count less than or equal to 100 × 10^9 cells /L.
• Creatinine clearance less than 50 mL/min.
• Aspartate aminotransferase (AST), or alanine aminotransferase (ALT) greater than or equal to 2.5 x upper limit of normal,Total Bilirubin greater than or equal to 2.5 x upper limit of normal.
• Cardiac and pulmonary status insufficient to undergo apheresis or transplantation.
• Active central nervous system (CNS) involvement, active brain metastases, or any history of carcinomatous meningitis.
• Active infection, including unexplained fever (greater than 38 degrees C), or antibiotic therapy within 7 days prior to the first dose of GCSF.
• Less than 6 weeks off nitrosoureas prior to first dose of G-CSF.
• Conditions/situations such as: received prior radio-immunotherapy with ibritumomab tiuxetan or tositumomab iodine, and received radiation therapy to the pelvis.
• Significant concomitant illness, including psychiatric condition that, in the opinion of the Investigator or Sponsor, would adversely affect the participant's participation in the study.
• Abnormal electrocardiogram (ECG) with clinically significant rhythm disturbance (ventricular arrhythmias) or other conduction abnormality in the last year that, in the opinion of the Investigator(s), warrants exclusion of the participants from the trial.
• Previously received experimental therapy within 4 weeks of randomization or who are currently enrolled in another experimental protocol during the G-CSF and plerixafor treatment period.
• Any malignancy related to immunodeficiency virus (HIV) or solid organ transplant; history of known HIV, unresolved viral hepatitis as documented at the detection of hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (HBsAb)[exclude patients who clearly received vaccination], hepatitis B core antibody (HBcAb), and/or hepatitis C virus (HCV) antibody at the time of the screening visit.
• Unwillingness and inability to comply with scheduled visits, drug administration plan, laboratory tests, other study procedures, and study restrictions.
• Related to the active comparator and/or mandatory background therapies.
• Received G-CSF within 7 days prior to the first dose of G-CSF for mobilization.
• Related to the current knowledge of Sanofi compound.
• Pregnant or breast-feeding women.
• All participants, who are sexually active (males and females), must agree to an effective method of contraception while on study treatment and for at least 3 months following plerixafor treatment (including both female participants of child-bearing potential and male participants with partners of childbearing potential).
• Patient who has withdrawn consent before enrollment/randomization.
• Despite screening of the patient, enrollment/randomization is stopped at the study level.

The above information is not intended to contain all considerations relevant to a patient's potential participation in a clinical trial.