Dr. Jewell is a hematology/oncology fellow, Dr. Xiang, Dr. Kunthur, and Dr. Mehta are staff hematologist/oncologists, all in the Division of Hematology/Oncology, Department of Internal Medicine, at the John L. McClellan Memorial Veterans Hospital in Little Rock, Arkansas. Dr. Xiang and Dr. Mehta are also faculty members at the University of Arkansas for Medical Sciences in Little Rock.
References
curative therapy for these patients. However, its high mortality rate precludes its everyday use.
Transplant-Ineligible Patients
For patients with newly diagnosed MM who are ineligible for ASCT due to age or other comorbidities, chemotherapy is the only option. Many patients will benefit not only in survival, but also in quality of life. Immunomodulatory agents, such as lenalidomide and thalidomide, and PIs, such as bortezomib, are highly effective and well tolerated. There has been a general shift to using these agents upfront in transplant-ineligible patients.
All previously mentioned regimens can also be used in transplant-ineligible patients. Although no longer the preferred treatment, melphalan can be considered in resource-poor settings. 11 Patients who are not transplant eligible are treated for a fixed period of 9 to 18 months, although lenalidomide plus dexamethasone is often continued until relapse. 11,33
Melphalan Plus Prednisone Plus Bortezomib
The addition of bortezomib to melphalan and prednisone results in improved OS compared with that of melphalan and dexamethasone alone. 34 Peripheral neuropathy is a significant AE and can be minimized by giving bortezomib once weekly.
Melphalan Plus Prednisone Plus Thalidomide
Melphalan plus prednisone plus thalidomide has shown an OS benefit compared with that of melphalan and prednisone alone. The regimen has a high toxicity rate ( > 50%) and a deep vein thrombosis rate of 20%, so patients undergoing treatment with this regimen require thromboprophylaxis. 35,36
Melphalan Plus Prednisone
Although melphalan plus prednisone has fallen out of favor due to the existence of more efficacious regimens, it may be useful in an elderly patient population who lack access to newer agents, such as lenalidomide, thalidomide, and bortezomib.
Assessing Treatment Response
The International Myeloma Working Group has established criteria for assessing disease response. Patient’s response to therapy should be assessed with a FLC assay before each cycle with SPEP and UPEP and in those without measurable M protein levels. A bone marrow biopsy can be helpful in patients with immeasurable M protein levels and low FLC levels, as well as to establish that a CR is present.
A CR is defined as negative SPEP/UPEP, disappearance of soft tissue plamacytomas, and < 5% plasma cells in bone marrow. A very good partial response is defined as serum/urine M protein being present on immunofixation but not electrophoresis or reduction in serum M protein by 90% and urine M protein < 100 mg/d. For those without measurable M protein, a reduction in FLC ratio by 90% is required. A partial response is defined as > 50% reduction of the serum monoclonal protein and/or < 200 mg urinary M protein per 24 hours or > 90% reduction in urinary M protein. For those without M protein present, they should have > 50% decrease in FLC ratio. 5
Maintenance Therapy
There is currently considerable debate about whether patients should be treated with maintenance therapy following induction chemotherapy or transplant. In patients
