A Study to Evaluate the Efficacy and Safety of Ixazomib in Combination With Lenalidomide and Dexamethasone in Patients With Relapsed and/or Refractory Multiple Myeloma Initially Treated With an Injection of Proteasome Inhibitor-Based Therapy

Inclusion Criteria

Eligibility for Treatment Period I

• Men and women of age 20 years or older at the time of enrollment.
• Participants with RRMM.
• Participants who are planned to start combination therapy with bortezomib, lenalidomide, and dexamethasone (VRd) or carfilzomib, lenalidomide, and dexamethasone (KRd) as second, third or fourth line of treatment.
• Participants with measurable disease defined by one or more of the following three measurements.
• Serum M-protein: ≥0.5 gram (g)/ deciliter (dL) (≥ 5 g/ liter [L])
• Urine M-protein: ≥ 200 milligram (mg)/24 hours
• Serum free light chain assay: involved free light chain concentration ≥ 10 mg/dL (≥ 100 mg/L) provided that the serum free light chain ratio is abnormal
• Participants with Eastern Cooperative Oncology Group (ECOG) performance status (PS) 0-2; however, participants with ECOG PS 3 are eligible if they only have symptoms associated with bone lesions.
• Participants who are considered by the principal investigator or investigator not to be eligible for transplant; or, if considered eligible for transplant, participants who are planned not to undergo transplant for at least 12 months after the start of the study treatment.
• Participants must be registered with, and comply with, the guidelines of the lenalidomide management program.
• Participants who, before implementing procedures related to clinical research (excluding standard medical practices), understand that they can withdraw consent at any time without suffering from disadvantages to future treatments, and can provide written informed consent.

Eligibility for Treatment Period II

• Participants must have received an injectable proteasome inhibitor (bortezomib or carfilzomib) in each treatment cycle of Treatment Period I.

Exclusion Criteria

Eligibility for Treatment Period I

• Women who are nursing or pregnant.
• Participants with another active malignancy, i.e. synchronous active malignancy or previous malignancy with a disease-free period of less than 5 years, except for participants with carcinoma in situ (intraepithelial carcinoma) or intramucosal carcinoma judged to be cured by topical treatment.
• Participants with poorly controlled active thrombosis.
• Participants who have participated in a clinical trial of ixazomib or have been treated with ixazomib.
• Participants who were refractory to either treatment regimen based on lenalidomide and/or proteasome inhibitor(s).

Note: Refractory MM is defined as PD on therapy or PD within 60 days after the last dose of a given therapy. Participants who have disease progressed 60 days after the last dose of a given therapy will be considered as relapsed in this study.

• Participants with ongoing or active systemic infection, known hepatitis B virus infection, known hepatitis C virus infection, or known positivity to human immunodeficiency virus (HIV).
• Participants who underwent major surgery within 14 days prior to enrollment to Treatment Period I. Surgery for bone lesions is not considered as major surgery.
• Participants who received radiation therapy within 14 days prior to enrollment to Treatment Period I. If the radiation field is small, 7 days is considered as a sufficient interval between radiation therapy and chemotherapy.
• Participants who experience Grade 1 peripheral neuropathy accompanied by pain, or Grade ≥2 peripheral neuropathy.
• Evidence of current uncontrolled cardiovascular conditions, including uncontrolled hypertension, uncontrolled cardiac arrhythmia, symptomatic congestive heart failure, unstable angina, or myocardial infarction within the past 6 months before enrollment to Treatment Period I.
• Infection requiring systemic antibiotic therapy or other serious infection within 14 days before enrollment into Treatment Period I.
• Participants with central nervous system involvement.
• Inability to swallow oral medications, inability or unwillingness to comply with the drug administration requirements