ixazomib—an orally available proteasome inhibitor indicated in combination with lenalidomide and dexamethasone in people who have received at least one prior therapy
panobinostat—an orally available histone deacetylase inhibitor used in combination with bortezomib and dexamethasone in people who have received at least two prior chemotherapy regimens, including bortezomib and an immunomodulatory agent
selinexor—an orally available selective inhibitor of nuclear export indicated in combination with dexamethasone in people who have received at least four prior therapies and whose disease does not respond to at least two proteasome inhibitors, two immunomodulatory agents and an anti-CD38 monoclonal antibody
idecabtagene vicleucel—first cell-based gene therapy was approved by FDA in 2021 for the treatment of adults with relapsed or refractory multiple myeloma who have received at least four prior therapies

Stem cell transplant
Stem cell transplant can be used to treat multiple myeloma. Stem cell transplants come with a risk of a graft-versus-host-disease. Mesenchymal stromal cells may reduce the all-cause mortality if they are used for a therapeutic reason and the therapeutic use of MSCs may increase the complete response of acute and chronic GvHD, but the evidence is very uncertain. The evidence suggests that MSCs for prophylactic reason result in little to no difference in the all-cause mortality, in the relapse of malignant diseases and in the incidence of acute GvHD. The evidence suggests that MSCs for prophylactic reason reduce the incidence of chronic GvHD.
Diagnostic criteria
In 2003, the IMG agreed on diagnostic criteria for symptomatic myeloma, asymptomatic myeloma, and MGUS, which was subsequently updated in 2009:
Symptomatic myeloma (all three criteria must be met):
Clonal plasma cells >10% on bone marrow biopsy or (in any quantity) in a biopsy from other tissues (plasmacytoma)
A monoclonal protein (myeloma protein) in either serum or urine and it has to be more than 3g/dL (except in cases of true nonsecretory myeloma)
Evidence of end-organ damage felt related to the plasma cell disorder (related organ or tissue impairment, CRAB):
HyperCalcemia (corrected calcium >2.75 mmol/L, >11 mg/dL)
Renal failure (kidney insufficiency) attributable to myeloma
Anemia (hemoglobin <10 g/dL)
Bone lesions (lytic lesions or osteoporosis with compression fractures)Note: Recurrent infections alone in a person who has none of the CRAB features is not sufficient to make the diagnosis of myeloma. People who lack CRAB features, but have evidence of amyloidosis, should be considered as amyloidosis and not myeloma. CRAB-like abnormalities are common with numerous diseases, and these abnormalities must be felt to be directly attributable to the related plasma cell disorder and every attempt made to rule out other underlying causes of anemia, kidney failure, etc. In 2014, the IMWG updated their criteria further to include biomarkers of malignancy. These biomarkers are >60% clonal plasma cells, a serum involved / uninvolved free light chain ratio ≥ 100 (the concentration of the involved free light chain must be ≥ 100 mg/L) and more than one focal lesion ≥ 5 mm by MRI. Together, these biomarkers and the CRAB criteria are known as myeloma-defining events (MDEs).