Renal recovery with lenalidomide in a patient with bortezomib-resistant multiple myeloma.

BACKGROUND: A 51-year-old man presented with an 8 month history of migratory pain and weakness. INVESTIGATIONS: Conventional X-ray, MRI, laboratory investigations including serum electropheresis and immunofixation, measurement of the glomerular filtration rate and levels of serum creatinine and lactate dehydrogenase, and 24 h urine analysis for proteinuria. DIAGNOSIS: Durie-Salmon stage IIIB multiple myeloma with IgG lambda gammopathy and renal impairment associated with urinary excretion of free lambda light chains. MANAGEMENT: Initially, the patient received supportive analgesia with metamizol and opioids, erythropoiesis-stimulating agents and monthly administration of bisphosphonates. A standard regimen of bortezomib, doxorubicin and dexamethasone was started, but the patient did not respond and developed severe renal failure. Treatment was switched to low-dose lenalidomide and high-dose dexamethasone. The lenalidomide dose was gradually increased up to 15 mg daily and the dexamethasone dose reduced to 40 mg once a week. Therapy was well tolerated, and the patient underwent autologous stem-cell transplantation around 16 months after start of induction treatment and 12 months after the start of lenalidomide-based therapy. At 2 years after initiation of lenalidomide-based therapy, the patient remains in partial remission with stable renal function and excellent performance status.