Lenalidomide Plus Rituxan for Untreated Mantle Cell Lymphoma

Induction Phase (week 1 - 48): * Lenalidomide will be given at 20 mg/day for days 1-21 of a 28-day cycle for 12 cycles. If no excess toxicity is observed the dose will be increased to 25 mg/day. * Rituximab will be administered at 375 mg/m2 per dose for a total of 9 doses. The first 4 doses will be administered weekly starting on day 1 of lenalidomide (e.g. days 1, 8, 15 and 22). Subsequent rituximab doses will be administered for one dose each at weeks 12, 20, 28, 36 and 44. Maintenance Phase (week 49 - progression of disease): * Lenalidomide will be given at 15 mg/day for days 1-21 of a 28-day cycle. * Rituximab at 375 mg/m2 per dose will be administered for one dose every 8 weeks, starting at week 52. Response Assessment * Year 1-2: Conventional restaging CT scan (or MRI) with IV contrast every 3 months from cycle 1 day 1 of the study. * Year 3 onwards: Conventional restaging CT scan (or MRI) with IV contrast every 6 months until progression.