⁃ Signed informed consent form Biopsy-proven MCL according to WHO classification

⁃ ≥ 60 years of age and ineligible for autologous transplant Ann Arbor stage II-IV Previously untreated ECOG PS ≤ 2

⁃ Male subjects must:

• agree to use a condom during sexual contact with a woman of childbearing potential, even if they have had a vasectomy, throughout lenalidomide therapy

• agree to not donate semen during lenalidomide therapy.

⁃ All subjects must:

• have an understanding that the lenalidomide could have a potential teratogenic risk.

• agree to abstain from donating blood while taking lenalidomide therapy

• agree not to share study medication with another person.

• be counselled about pregnancy precautions and risks of foetal exposure.

⁃ Additional criteria for randomization in maintenance phase:

• CR, CRu or PR after induction treatment, determined as per Cheson 1999 criteria

• During the run-in period of 6 months starting from the date of the first randomization in the trial: in case of direct randomization into maintenance phase, patient must have been treated in first line by 6-8 cycles of R-CHOP.