A Study of JNJ-64407564 in Japanese Participants With Relapsed or Refractory Multiple Myeloma

Inclusion Criteria:

• Documented diagnosis of multiple myeloma according to International Myeloma WorkingGroup (IMWG) diagnostic criteria

• Participants must be relapsed or refractory to established therapies with knownclinical benefit in relapsed/refractory multiple myeloma (MM) or be intolerant ofthose established MM therapies, and a candidate for talquetamab treatment in theopinion of the treating physician. Prior lines of therapy must include a proteasomeinhibitor (PI), an immunomodulatory drug (IMiD) and an anti-CD38 antibody in anyorder during the course of treatment. Participants who could not tolerate a PI,immunomodulatory drugs or anti-CD38 antibody are allowed

• Eastern cooperative oncology group (ECOG) performance status grade of 0 or 1 atscreening and immediately before the start of study treatment administration

• Women of childbearing potential must have a negative pregnancy test at screening andwithin 24 hours prior to the first dose of study treatment using highly sensitivepregnancy test either serum (Beta-human chorionic gonadotropin [Beta-hCG]) or urine

• Participants (or a legally acceptable representative) must sign an informed consentform (ICF) indicating that he or she understands the purpose of, and proceduresrequired for, the study and is willing to participate in the study. Consent is to beobtained prior to the initiation of any study-related tests or procedures that arenot part of standard-of-care for the participant's disease

Exclusion Criteria:

• Toxicities from previous anticancer therapies that have not resolved to baselinelevels or to Grade 1 or less except for alopecia or peripheral neuropathy

• Received a cumulative dose of corticosteroids equivalent to >=140 milligrams (mg) ofprednisone within the 14-day period before the first step-up dose of study treatment (does not include pretreatment medication)

• Central nervous system involvement or clinical signs of meningeal involvement ofmultiple myeloma. If either is suspected, whole brain magnetic resonance imaging (MRI) and lumbar cytology are required during screening

• Pulmonary compromise requiring supplemental oxygen use to maintain adequateoxygenation

• Known allergies, hypersensitivity, or intolerance to the excipients of talquetamab