Lenalidomide and Low-Dose Dexamethasone in Patients With Previously Treated Multiple Myeloma and Kidney Dysfunction

Multiple Myeloma (MM) affects approximately 20,000 Americans annually and remains an incurable hematologic malignancy characterized by frequent early response followed by universal treatment relapse necessitating multiple sequential therapeutic regimens. Until recently, few effective therapies existed. Several novel agents for MM have now become available including the immunomodulatory drugs thalidomide, lenalidomide, as well as the proteasome inhibitor, bortezomib. Each of these agents is undergoing extensive clinical evaluation in combination with other therapies to produce unprecedented response rates in newly diagnosed and relapsed MM. Lenalidomide has proven to be a highly effective treatment agent, particularly when used in combination with dexamethasone but is renally excreted and little information is available about its use in myeloma patients with impaired kidney function (20% have renal failure at some time after diagnosis). Defining a safe and effective dose of lenalidomide to use is a critical step in MM treatment. OUTLINE: This is a Phase I, dose-escalation study of lenalidomide followed by a Phase II study. Patients are stratified according to degree of renal dysfunction (moderate \[creatinine clearance 30-60 mL/min\] vs severe \[creatinine clearance \<30 mL/min and does not require dialysis\] vs end-stage renal disease \[creatinine clearance \<30 mL/min and requires dialysis\]). Patients receive oral lenalidomide on days 1-21 and low-dose oral dexamethasone 40 mg on days 1, 8, 15, and 22. There is a 7 day rest (days 22-28) from lenalidomide. Each cycle is 28 days and repeated in the absence of disease progression or unacceptable toxicity. Patients enrolled in the phase II portion of the study will undergo blood sample collection periodically for pharmacokinetic analysis of lenalidomide (Mayo Clinic sites only). After completion of study treatment, patients are followed every 6 months for up to 3 years.