The following criteria is provided for health care professionals.

Inclusion Criteria:

• Documented diagnosis of multiple myeloma according to International Myeloma Working Group (IMWG) diagnostic criteria
• Measurable multiple myeloma that is relapsed or refractory to established therapies with known clinical benefit in relapsed/refractory multiple myeloma or be intolerant of those established multiple myeloma therapies, and a candidate for Teclistamab treatment in the opinion of the treating physician. Prior lines of therapy must include a proteasome inhibitor, an immunomodulatory drug and anti-CD38 monoclonal antibody in any order during the course of treatment. Participants who could not tolerate a proteasome inhibitor or immunomodulatory drugs and an anti-CD38 monoclonal antibody are allowed
• Eastern Cooperative Oncology Group (ECOG) Performance Status score of 0 or 1
• Women of childbearing potential and fertile men who are sexually active must agree to use a highly effective method of contraception (less than [<] 1%/year failure rate) during the study and for 90 days after the last dose of study drug. Contraception must be consistent with local regulations regarding the use of birth control methods for participants participating in clinical trials. When a woman is of childbearing potential the following are required: A woman using hormonal contraceptives must use an additional barrier method (failure rate of <1% per year when used consistently and correctly). Examples of highly effective contraceptives for women include user-independent methods (for example, implantable progestogen-only hormone contraception associated with inhibition of ovulation; intrauterine device; intrauterine hormone-releasing system; vasectomized partner) and user-dependent methods (for example: combined [estrogen- and progestogen-containing] hormonal contraception associated with inhibition of ovulation [oral/intravaginal/ transdermal]; progestogen-only hormone contraception associated with inhibition of ovulation [oral/injectable]. In addition to the highly effective method of contraception, a man who is sexually active with a woman of childbearing potential must agree to use a barrier method of contraception (for example a condom with spermicidal foam/gel/film/cream/suppository). Additionally, a man who is sexually active with a woman who is pregnant must use a condom. Women and men must agree not to donate eggs (ova, oocytes) or sperm, respectively, during the study and for 90 days after the last dose of study drug
• Participants 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:

• Prior treatment with any B cell maturation antigen (BCMA) targeted therapy
• Prior antitumor therapy as follows, before the first dose of study drug: Targeted therapy, epigenetic therapy, or treatment with an investigational drug or used an invasive investigational medical device within 21 days or at least 5 half-lives, whichever is less; Monoclonal antibody treatment for multiple myeloma within 21 days; Cytotoxic therapy within 21 days; Proteasome inhibitor therapy within 14 days; Immunomodulatory agent therapy within 7 days; Gene modified adoptive cell therapy (example, chimeric antigen receptor modified T cells, natural killer [NK] cells) within 3 months; Radiotherapy within 14 days or focal radiation within & days
• 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 milligram (mg) of prednisone within the 14-day period before the first dose of study drug (does not include pretreatment medication)
• Known active central nervous system (CNS) involvement or exhibits clinical signs of meningeal involvement of multiple myeloma