A Study of mRNA-2808 in Participants With Relapsed or Refractory Multiple Myeloma

Must have received: proteasome inhibitor

prior exposure to a proteasome inhibitor

Must have received: immunomodulatory drug

prior exposure to an immunomodulatory drug (IMiD)

Must have received: anti-CD38 monoclonal antibody

prior exposure to an anti-cluster of differentiation (CD38) monoclonal antibody

Cannot have received: radiotherapy

Exception: palliative radiotherapy of limited field is permissible within 2 weeks after discussion with the Sponsor medical monitor

Radiotherapy or cytotoxic chemotherapy within 2 weeks prior to Day 1 (Baseline)

Cannot have received: cytotoxic chemotherapy

Radiotherapy or cytotoxic chemotherapy within 2 weeks prior to Day 1 (Baseline)

Cannot have received: antibody-based immunotherapy

Antibody-based immunotherapy (monoclonal antibody, bispecific antibody, antibody drug conjugate) within 21 days prior to Day 1 (Baseline)

Cannot have received: proteasome inhibitor

Proteasome inhibitor therapy ... within 14 days prior to Day 1 (Baseline)

Cannot have received: immunomodulatory drug

immunomodulatory agent within 14 days prior to Day 1 (Baseline)

Cannot have received: autologous hematopoietic cell transplant

Autologous hematopoietic cell transplant within 100 days prior to Day 1 (Baseline)

Cannot have received: allogeneic hematopoietic cell transplant

Allogeneic hematopoietic cell transplant within 180 days prior to Day 1 (Baseline)

Cannot have received: genetically modified adoptive cellular therapy (chimeric antigen receptor T cell, chimeric antigen receptor natural killer)

Genetically modified adoptive autologous or allogeneic cellular therapy (for example, chimeric antigen receptor T cell, chimeric antigen receptor natural killer) within 12 weeks prior to Day 1 (Baseline)

Cannot have received: corticosteroid

Corticosteroid therapy ≥140 mg prednisone or equivalent cumulative dose within 14 days prior to Day 1 (Baseline)