This is a prospective, multicenter phase II trial designed to evaluate the safety and activity of the combination of Lenalidomide (Len) and Dexamethasone (Dex) in patients with relapsed/refractory mantle cell lymphoma (MCL).

Inclusion Criteria:

• Diagnosis of MCL
• Understand and voluntarily sign an informed consent form;
• Able to adhere to the study visit schedule and other protocol requirements;
• Age ≥ 18;
• Patients treated with at least one prior treatment regimen, not eligible for or relapsed after more intensive treatments (stem cell transplant);
• Patients with refractory or relapsed disease;
• Measurable and/or valuable disease;
• Adequate haematological counts: ANC > 1.5 x 109/L and platelet count > 75 x 109/L unless due to bone marrow involvement by MCL;
• Conjugated bilirubin up to 2 x ULN unless due to liver involvement by MCL;
• Alkaline phosphatase and transaminases up to 2 x ULN unless due to liver involvement by MCL;
• Creatinine clearance ≥ 50 ml/min;
• HIV negativity;
• HCV negativity;
• HBV negativity or patients with HBcAb +, HbsAg -, HBs Ab+/- and anti HBV prophylaxis with lamivudine;
• Non peripheral neuropathy or CNS disease;
• Life expectancy > 6 months;
• Performance status < 2 according to ECOG scale;Disease free of prior malignancies (a part MCL) with the exception of currently treated basal cell, squamous cell carcinoma of the skin, or carcinoma "in situ" of the cervix or breast;
• Written informed consent;
• Females of childbearing potential (FCBP) must agree to use two reliable forms of contraception simultaneously or to practice complete abstinence from heterosexual intercourse during the following time periods related to this study: 1) for at least 28 days before starting study drug; 2) while participating in the study; and 3) for at least 28 days after discontinuation from the study. The two methods of reliable contraception must include one highly effective method (i.e. intrauterine device (IUD), hormonal [birth control pills, injections, or implants], tubal ligation, partner's vasectomy) and one additional effective (barrier) method (i.e. latex condom, diaphragm, cervical cap). FCBP must be referred to a qualified provider of contraceptive methods if needed;

Exclusion Criteria:

• Patients who have received an experimental drug or used an experimental medical device within 4 weeks before the planned start of treatment. Concurrent participation in non-treatment studies is allowed, if it will not interfere with participation in this study;
• CNS disease (meningeal and/or brain involvement by lymphoma);
• TVP in the last year;
• History of clinically relevant liver or renal insufficiency; significant cardiac, vascular, pulmonary, gastrointestinal, endocrine, neurologic, rheumatologic, hematologic, psychiatric, or metabolic disturbances;
• Uncontrolled diabetes (if receiving antidiabetic agents, subjects must be on a stable dose for at least 3 months before first dose of study drug);
• Creatinine clearances < 50 ml/min;
• HIV positivity;
• HBV positivity with the exception of patients with HBVcAb +, HbsAg -, HBs Ab+/- in anti HBV prophilaxis with lamivudine;
• Pregnant or lactating women;
• Hypersensitivity reactions to previous thalidomide (if any);
• Prior rash ≥ 3 while taking thalidomide (if any);
• Active opportunistic infection;
• Any other co-existing medical or psychological condition that would preclude participation in the study or compromise ability to give informed consent;