II. Obtain evidence of reovirus entry into myeloma cells via localization of reoviral ribonucleic acid (RNA) in multiple myeloma (MM) cells in situ hybridization (ISH), and active viral proliferation/replication via localization of reoviral capsid protein immunohistochemistry (IHC) in MM cells in cycle 1 day 9 bone marrow biopsies in all patients enrolled in dose escalation cohorts.