This study aims to compare how belantamab behaves in the body when given as an injection under the skin (SC) versus into a vein (IV) in participants with multiple myeloma who are receiving standard of care treatment, to enable eventual development of SC formulation. It will assess how much belantamab is absorbed and how long it stays in the blood as well as assess whether it is safe and tolerated well by participants.
Participants at the time of signing the Informed Consent Form (ICF) must be aged 18 years old or greater or are of the legal age of consent in the jurisdiction in which the study is taking place.
Histologically or cytologically confirmed diagnosis of multiple myeloma (MM), as defined by the International Myeloma Working Group (IMWG).
Currently receiving maintenance therapy with either anti- cluster of differentiation 38 (anti-CD38) directed therapy, or lenalidomide, or both, following autologous stem cell transplantation (ASCT) in either first or second line.
No change in current myeloma treatment for at least 2 months prior to during screening, or during the trial.
Diagnosis of primary Amyloid Light chain (AL) Amyloidosis, active polyneuropathy, organomegaly, endocrinopathy, monoclonal plasma cell disorder, and skin changes (POEMS) syndrome, primary plasma cell leukemia, or non-secretory myeloma.
Any serious and/or unstable pre-existing medical, psychiatric disorder, or other conditions (including lab abnormalities) that could interfere with participant's safety, obtaining informed consent, or compliance with study procedures.
Has cirrhosis or current unstable liver or biliary disease per investigator assessment defined by the presence of ascites, encephalopathy, coagulopathy, hypoalbuminemia, esophageal/gastric varices, or persistent jaundice.
Known immediate or delayed hypersensitivity reaction or idiosyncrasy to drugs chemically related to belantamab, or hyaluronidase, or any of the components of the study treatment. History of severe hypersensitivity to other monoclonal antibodies (mAbs).