CONSORT diagram of patient treatment and disposition. The induction treatment consisted of lenalidomide (Len) administered at 20 mg daily on days 1 to 21 of a 28-day cycle for 12 cycles and rituximab (R) weekly for 4 weeks during cycle 1 and then every other cycle. Of the 38 patients enrolled, 33 completed induction and entered maintenance, whereas Len was reduced to 15 mg, and R was continued every other cycle. Treatment was continuous until disease progression, unacceptable toxicity, or study withdrawal, with an option to stop therapy after 3 years. AE, adverse event; NE, not evaluable; PD, progressive disease.