Inclusion Criteria:

- Histology:

1. Patients with any type of B-cell Lymphoma except CLL, SLL and Waldenström
disease will be eligible during the dose escalation phase

2. During the expansion phases, patients with DLBCL for cohort A, mantle cell
lymphoma for cohort B and any other type of B-cell lymphoma except CLL, SLL and
Waldenström disease for cohort C.

- Other criteria:

- Signed inform consent

- Patients should be relapsed or refractory NHL after ≥1 prior
Rituximab-containing regimen for which no other type of therapy is of higher
priority

- Aged 18 years or more.

- ECOG performance status 0-2.

- Measurable disease defined by at least one single node or tumor lesion > 1.5 cm.

- Life expectancy of ≥ 90 days (3 months).

- Patients must be eligible and willing to undergo excisional biopsies of tumor
sites with a lymph node of minimum 1 cm at baseline and after 21 days of
treatment

- Females of childbearing potential (FCBP)† must have two negative serum or urine
pregnancy tests with a sensitivity of at least 25 mIU/mL before starting
lenalidomide - the first test must be performed within 10-14 days before
starting lenalidomide treatment and the second test must be performed within 24
hours before starting lenalidomide

- FCBP must either commit to continued abstinence from heterosexual intercourse or
begin two methods of birth control, at least 4 weeks before she starts taking
lenalidomide. FCBP must also agree to monthly pregnancy testing and must be
counseled at a minimum of every 4 weeks about pregnancy precautions and risks of
fetal exposure.

- Men must agree not to father a child and agree to use a condom if his partner is
of child bearing potential. Men must also be counseled at a minimum of every 4
weeks about pregnancy precautions and risks of fetal exposure.

Exclusion Criteria: