Inclusion Criteria:  Who first diagnosed with MM using IMWG 2016 criteria.  Diagnosed with multiple myeloma using IMWG 2016 criteria and must be transplant ineligible as determined by their physician, or if transplant eligible, not expect to undergo transplant for at least 24 months after study enrollment.  o Stem cell harvest and mobilization regimen is acceptable if clinically indicated. But must first be confirmed by the Takeda Medical Monitor.  Who received bortezomib-based triple-drug regimens as frontline treatment, including bortezomib+cyclophosphamide+dexamethasone (VCD), bortezomib+lenalidomide dexamethasone (VRD), bortezomib+doxorubicin+dexamethasone (PAD), bortezomib+thalidomide+dexamethasone (VTD). Must achieve partial response (PR) as defined by IMWG 2016 criteria after bortezomib-based initial therapy. Eastern Cooperative Oncology Group (ECOG) 0-2.  Exclusion Criteria:  Received a bortezomib-based triple-drug regimens as initial therapy less than 2 cycles. Failure to have fully recovered (that is, less than or equal to [<=] Grade 1 toxicity) from the reversible effects of prior chemotherapy. Have documented diagnosis of other cancers prior to the diagnosis of MM, excluding squamous and basal cell carcinomas of the skin, carcinoma in situ of the cervix or breast, which is considered cured with minimal risk of recurrence within 3 years. Has >=Grade 2 peripheral neuropathy (PN), or Grade 1 with pain on clinical examination at the time of enrollment. Previously been treated with ixazomib or participated in a study with ixazomib whether treated with ixazomib or not. Have gastrointestinal (GI) disease or GI procedure that could interfere with the oral absorption or tolerance of ixazomib including difficulty swallowing. Have an active systemic infection, active hepatitis B or C virus infection, or known human immunodeficiency virus positive.