The following criteria is provided for health care professionals.

Inclusion Criteria:

1. Has MM defined by the IMWG criteria with evidence of disease progression and:
   • Is in need of additional myeloma therapy as determined by the investigator.
   • Has previously received at least 3 lines of myeloma therapy.
   • Is either refractory to or intolerant of at least one protesome inhibitor and a least one immunomodulatory drug.

   In addition, after the MTD is defined, must also be either refractory to or intolerant of at least one anti-CD38 monoclonal antibody.

2. For participants in MTD cohort expansion and Phase 2 only: participant has measurable disease.
3. During dose escalation only, participants not meeting the above criteria for measurable disease should, at least, have measurable bone marrow plasmacytosis (greater than or equal to [>=] 10%) and/or plasmacytoma (>=1 centimeter [cm] in diameter) detected by physical examination or imaging.
4. Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 2.

Exclusion Criteria:

1. Has polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, and skin changes (POEMS) syndrome, monoclonal gammopathy of unknown significance, smoldering myeloma, solitary plasmacytoma, amyloidosis, Waldenström macroglobinemia or immunoglobulin M (IgM) myeloma, or lymphoplasmacytic lymphoma (LPL).
2. Has sensory or motor neuropathy of >= National Cancer Institute Common Terminology Criteria for AEs (NCI CTCAE) Grade 3.
3. Who have received autologous stem cell transplant (SCT) 60 days before first infusion of TAK-573 or participants who have received allogeneic SCT 6 months before first infusion. Graft-versus-host disease that is active or requires ongoing systemic immunosuppression.
4. Has not recovered from adverse reactions to prior myeloma treatment or procedures (chemotherapy, immunotherapy, radiation therapy) to NCI CTCAE less than or equal to (<=) Grade 1 or baseline, except for sensory or motor neuropathy which should have recovered to <=Grade 2 or baseline.
5. Has clinical signs of central nervous system (CNS) involvement of MM.