Patients receive induction therapy comprising bortezomib intravenously (IV) over 3-5 seconds on days 1, 4, 8, and 11 and lenalidomide orally (PO) once daily (QD) on days 1-14. Treatment repeats every 21 days for up to 8 courses in the absence of disease progression or unacceptable toxicity. Patients achieving a complete or partial response as best response after completion of induction therapy receive maintenance therapy comprising bortezomib IV on days 1 and 8 and lenalidomide PO QD on days 1-14. Treatment repeats every 21 days for up to 6 years in the absence of disease progression or unacceptable toxicity.