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

A Phase 1 Study of JNJ-64407564, a Humanized GPRC5D * CD3 Bispecific Antibody in Japanese Subjects With Relapsed or Refractory Multiple Myeloma

The purpose of this study is to evaluate the safety and tolerability in Japanese participants with relapsed or refractory multiple myeloma (MM) at the recommended Phase 2 dose (RP2D) identified in NCT03399799 study.

Inclusion Criteria:

• Documented diagnosis of multiple myeloma according to International Myeloma Working Group (IMWG) diagnostic criteria
• Participants must be relapsed or refractory to established therapies with known clinical benefit in relapsed/refractory multiple myeloma (MM) or be intolerant of those established MM therapies, and a candidate for talquetamab treatment in the opinion of the treating physician. Prior lines of therapy must include a proteasome inhibitor (PI), an immunomodulatory drug (IMiD) and an anti-CD38 antibody in any order 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 at screening and immediately before the start of study treatment administration
• Women of childbearing potential must have a negative pregnancy test at screening and within 24 hours prior to the first dose of study treatment using highly sensitive pregnancy test either serum (Beta-human chorionic gonadotropin [Beta-hCG]) or urine
• Participants (or a legally acceptable representative) must sign an informed consent form (ICF) indicating that he or she understands the purpose of, and procedures required for, the study and is willing to participate in the study. Consent is to be obtained prior to the initiation of any study-related tests or procedures that are not part of standard-of-care for the participant's disease

Exclusion Criteria:

• Toxicities from previous anticancer therapies that have not resolved to baseline levels or to Grade 1 or less except for alopecia or peripheral neuropathy
• Received a cumulative dose of corticosteroids equivalent to >=140 milligrams (mg) of prednisone 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 of multiple 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 adequate oxygenation
• Known allergies, hypersensitivity, or intolerance to the excipients of talquetamab