Management of Multiple Myeloma with Severe Renal Impairment

Immediate Diagnostic Workup

• The National Comprehensive Cancer Network recommends obtaining serum free light chain assay, 24-hour urine collection with electrophoresis, serum electrophoresis and immunofixation, and electrolytes, calcium, and uric acid levels to characterize the renal impairment and guide management 2, 4

First-Line Antimyeloma Therapy

• The National Comprehensive Cancer Network guidelines recommend bortezomib/dexamethasone-containing regimens as the treatment of choice for multiple myeloma with severe renal impairment, which can be initiated immediately without waiting for renal function assessment and do not accumulate in renal failure 1, 3, 6
• Bortezomib-based regimens achieve renal response in 40-50% of patients with severe renal impairment, with median time to improvement of 17-35 days 1, 3, 6
• Cyclophosphamide, daratumumab, thalidomide, and anthracycline (doxorubicin) can be added as a third agent to bortezomib and dexamethasone, as they do not require dose adjustment in renal impairment 1, 3

Aggressive Supportive Care Measures

• Administer intravenous fluids immediately with target urine output of 100-150 mL/hour to reduce tubular light chain concentration 1, 2, 3
• Discontinue all nephrotoxic medications, including NSAIDs, IV contrast, and aminoglycosides, to prevent further renal injury 1, 2, 6
• Treat hypercalcemia aggressively using hydration plus bisphosphonates, denosumab, or calcitonin 1, 2

Extracorporeal Light Chain Removal

• For patients with serum free light chain >150 mg/dL, add daily plasma exchange to chemotherapy to reduce free light chain levels by 45-75% per session 8
• High cut-off hemodialysis is an alternative that removes 60-75% of free light chains per session and may be more effective than conventional plasma exchange 8

Transplant Eligibility

• High-dose melphalan with autologous stem cell transplantation can be safely performed in patients with severe renal impairment, including those on dialysis, using reduced-dose melphalan (140 mg/m² instead of 200 mg/m²) with comparable outcomes to standard dosing 1, 3, 4

Critical Pitfalls to Avoid

• Do not delay antimyeloma therapy while waiting for diagnostic workup completion, as rapid reduction of light chain production is the single most important determinant of renal recovery 1, 6, 8
• Do not use standard lenalidomide dosing without renal adjustment, as this will lead to severe toxicity including thrombocytopenia and treatment discontinuation 1, 3