Multiple Myeloma Treatment Guidelines

Initial Treatment and Induction Therapy

The initial treatment for patients diagnosed with multiple myeloma should be a bortezomib-based regimen, which has shown superior outcomes in terms of mortality reduction and improved progression-free survival, as recommended by the National Comprehensive Cancer Network 1, 2
A bortezomib-based triplet regimen, with a preferred option being bortezomib, lenalidomide, and dexamethasone (VRd), is recommended for induction therapy 2
An alternative induction therapy option is bortezomib, thalidomide, and dexamethasone (VTd) 1

High-dose melphalan followed by autologous stem cell transplantation (ASCT) is recommended for consolidation, as recommended by the National Comprehensive Cancer Network 1
Lenalidomide or bortezomib-based maintenance therapy is recommended for maintenance, with a high level of evidence 2

Multiple myeloma is diagnosed based on the presence of ≥10% clonal plasma cells or plasmacytoma, plus CRAB features or other myeloma defining events, as outlined in the diagnostic criteria table:

Disorder	Diagnostic Criteria
MGUS	• Serum monoclonal protein <3 g/dl • Clonal bone marrow plasma cells <10% • Absence of CRAB features
Smoldering MM	• Serum monoclonal protein (IgG or IgA) ≥3 g/dl and/or clonal bone marrow plasma cells ≥10% • Absence of CRAB features
Multiple Myeloma	• ≥10% clonal plasma cells or plasmacytoma • PLUS CRAB features or other myeloma defining events [3]

CRAB features include Hypercalcemia, Renal insufficiency, Anemia, and Bone lesions, which are used to diagnose symptomatic multiple myeloma, as recommended by the International Myeloma Society 3

A comprehensive diagnostic workup, including complete blood count, comprehensive metabolic panel, serum protein electrophoresis, quantitative immunoglobulins, serum free light chain assay, and 24-hour urine for total protein, urine protein electrophoresis, and urine immunofixation, should be ordered when multiple myeloma is suspected, as recommended by the National Comprehensive Cancer Network 4, 5
Imaging studies, including plain radiographs, CT/MRI, and chest CT, should be performed to evaluate bone disease and rule out lung metastases, with a moderate level of evidence 6
Bone marrow aspiration and biopsy should be performed to confirm diagnosis, with ≥10% clonal plasma cells required for diagnosis, as recommended by the International Myeloma Society 4, 5
Cytogenetic studies, including FISH for high-risk features, should be performed in patients with suspected myeloma, with a moderate level of evidence 4

The International Staging System (ISS) combines beta-2 microglobulin, albumin, and LDH levels to determine the stage of multiple myeloma, as recommended by the International Myeloma Society, with a high level of evidence, with the following stages:

Risk stratification should be performed using the ISS and cytogenetic abnormalities from FISH analysis, as recommended by the International Myeloma Society, with a moderate level of evidence 8, 9

For Primary Plasma Cell Leukemia (PPCL), aggressive multi-phase therapy is required, including induction with bortezomib-based regimens, followed by ASCT, consolidation, and maintenance with short treatment-free intervals, as recommended by the National Comprehensive Cancer Network 1
For POEMS Syndrome, localized disease can be treated with radiation therapy, while disseminated disease requires systemic treatment avoiding agents that worsen polyneuropathy, with a moderate level of evidence 1
For AL Amyloidosis, treatment depends on cardiac involvement, with melphalan/dexamethasone or bortezomib-based regimens being generally recommended, as recommended by the International Myeloma Society 1
For frail patients, lenalidomide plus low-dose dexamethasone is a recommended first-line therapy option, with a moderate level of evidence 2

The NCCN recommends initiating treatment with a regimen based on eligibility for transplant, including bortezomib, lenalidomide, and dexamethasone for transplant-eligible patients, and daratumumab, lenalidomide, and dexamethasone for transplant-ineligible patients, with a high level of evidence 10
Close observation without immediate treatment is recommended for patients with smoldering multiple myeloma, with monitoring every 3-4 months, as recommended by the International Myeloma Society, with a moderate level of evidence 3
Regular monitoring of serum and urine M-protein levels, assessment of minimal residual disease (MRD) in patients achieving complete response, and periodic imaging to evaluate bone disease response are essential for multiple myeloma management, as recommended by the NCCN, with a moderate level of evidence 11
Bisphosphonates are recommended to reduce skeletal-related events, and radiation therapy may be necessary for painful bone lesions or impending fractures, as recommended by the American Cancer Society, with a moderate level of evidence 5, 11
Regular evaluation for treatment-related toxicities is essential to ensure optimal patient outcomes, as recommended by the European Society for Medical Oncology, with a moderate level of evidence 11