The following criteria is provided for health care professionals.

Inclusion Criteria:

• Multiple myeloma meeting the following criteria:
  • Pathologically-documented diagnosis of multiple myeloma that is relapsed or is refractory as defined by the following:
    • Relapsed after > or = 3 lines of prior therapy that must include a proteasome inhibitor (PI), an immunomodulatory drug (IMiD), and, where approved and available, a CD38-directed cytolytic antibody in combination in the same line or separate lines of treatment OR refractory to PI, IMiD, and CD38- directed cytolytic antibody,
    • Subjects who could not tolerate a PI, IMiDs, or a CD38-directed cytolytic antibody are eligible to enroll in the study.
  • Measurable disease as per IMWG response criteria
• Eastern Cooperative Oncology Group (ECOG) Performance Status of ≤ 2

Exclusion Criteria:

• Known extramedullary relapse in the absence of any measurable medullary involvement
• Known central nervous system involvement by multiple myeloma
• Autologous stem cell transplantation less than 90 days prior to study day 1
• Known history of primary plasma cell leukemia or evidence of primary or secondary plasma cell leukemia at the time of screening
• Waldenstrom's macroglobulinemia
• Prior amyloidosis (patients with multiple myeloma with asymptomatic deposition of amyloid plaques found on biopsy would be eligible if all other criteria are met)
• Treatment with systemic immune modulators including, but not limited to, nontopical systemic corticosteroids (unless the dose is ≤ 10 mg/day prednisone or equivalent), cyclosporine, and tacrolimus within 2 weeks before study day 1
• Last anticancer treatment (chemotherapy, IMiD, PI, molecular targeted therapy) < 2 weeks prior to study day 1 or treatment with a therapeutic antibody less than 4 weeks prior to study day 1 as well as systemic radiation therapy within 28 days prior to study day 1 or focal radiotherapy within 14 days prior to study day 1.
• Prior treatment with any drug or construct that targets BCMA on tumor cells (eg, other bispecific antibody constructs, antibody drug conjugates, or CAR-T cells), other than Group C where prior treatment with GSK2857916 (belantamab mafodotin) is required.