1. Clarified that the determination of tumor response and DOR was based on the 1999 IWRC. 2. Clarified that the evaluation of response using FDG-PET scans was based on the 2007 IWRC and that this was an exploratory evaluation. 3. Clarified that all exploratory objectives were optional for both sites and subjects. 4. Clarified that the requirement for collection of bone marrow biopsy/aspirate in cases of radiologic CR were to be obtained within 28 days from the scan confirming the CR. 5. Added language to further outline the medical management of TLS, including grading and treatment based on local standard of care with vigorous IV hydration and rasburicase. 6. Added guidance on the detection of TEEs. 7. Clarified Exclusion Criterion 6 that subjects who were candidates for high-dose chemotherapy/autologous or allogeneic transplant at the time of enrollment were not eligible unless other conditions were clearly documented (see Section 9.3.1). 8. Removed Exclusion Criterion 14, subjects with ≥ Grade 2 neuropathy. 9. Added dose modifications for subjects who developed Grade 3 peripheral neuropathy and for subjects who developed abnormal liver enzymes on study. 10. Clarified that the preferred method for assessment of tumor burden was conventional (or spiral) CT with contrast and that CT scans without contrast could be used but were not preferred. 11. Clarified that both target and non-target lesions were to be considered when assessing response and date of progression. 12. Clarified that radiographic assessments of tumor lesions were to be obtained every 56 days (± 7 days) from Cycle 1, Day 1. 13. Added language that subjects who discontinued from treatment who had not progressed were to be followed every 56 days (± 7 days) and that scans were required every 90 days (± 14 days) until PD or subsequent anti-lymphoma treatment.

1. Based on a recommendation from a European Union competent authority, the section on VTEs was updated to clarify that the investigators should choose the most appropriate antithrombotic prophylaxis for each subject, taking into account the individual thrombotic risk (eg, history of venous thrombosis), bleeding risk, and the quality of compliance with antithrombotic treatment. 2. Shortened the steroid washout period from 4 weeks to 1 week and permitted treatment of exacerbated conditions with peak doses of steroids > 10 mg for a limited time. 3. Clarified Exclusion Criterion 3 for elevated serum total bilirubin and elevated AST or ALT. Subjects with serum total bilirubin > 1.5 x ULN were excluded, except in cases of Gilbert’s syndrome or documented liver involvement by lymphoma. Subjects with ALT or AST > 3.0 x ULN were excluded, except those with documented liver involvement by lymphoma. 4. Dose modifications for subjects with abnormal liver function were clarified and aligned with the exclusion criterion regarding exceptions. 5. Added dose modifications for TFR and TLS. 6. Added an allowance for more than one dose reduction per cycle after consultation with the clinical research physician. 7. Changed the timing of study termination to occur after 70% of the subjects had died or a maximum of 4 years from enrollment of the last subject, whichever occurred first.

1. Added the requirement that SPMs be treated as SAEs and reported from the time of informed consent up to and including study termination. 2. Clarified that tumor/lymph node biopsy specimens were to be sent to the central pathology laboratory for confirmation of MCL preferably before enrollment, but no later than 8 weeks after enrollment. 3. Added an allowance for bone marrow aspirates/biopsies to be used in rare situations when archival tumor tissue specimens were not available and re-biopsy was not possible or put the subject at risk. 4. Added an allowance for baseline radiographic scans to be conducted > 28 days prior to Cycle 1, Day 1 with prior clinical research physician approval to limit subject exposure to radiation. 5. Removed the requirement for collecting time of, and best response to, first anti-lymphoma treatment used after discontinuation from this study. 6. For sites in Germany, the following change was also included in Amendment 3.0 DE: Per the Health Authority, removed the requirement that the investigator obtain clinical research physician approval for a second dose reduction within a cycle.

1. Based on a Health Authority request, added back in the requirement for collecting time of and best response to first anti-lymphoma treatment used after discontinuation from this study.

1. Expanded Exclusion Criterion 10 to require subjects to be free of any other malignancies except for MCL for at least 5 years (from at least 3 years) prior to study entry. This resulted from multivariate analyses conducted by the sponsor that demonstrated that subjects with a history of prior invasive malignancies are at risk for developing another malignancy during lenalidomide-containing therapy. 2. Increased the follow-up time for subjects for the reporting of cases of SPM from 4 to 5 years after enrollment of the last subject.

1. The timing of the treatment phase CT or MRI diagnostic imaging was modified to occur every 56 (± 7days) for the first 2 years and then every 4 months (± 2 weeks) until disease progression or start of a new anti-lymphoma therapy.

1. Based on a postmarketing commitment issued by the FDA, the follow-up of all subjects, for both safety and efficacy, was to continue for 4 years from date the last subject enrolled, or until the time of 100% of subjects died, were lost to follow-up, or had withdrawn consent, whichever came first. 2. The follow-up time for subjects for the reporting of cases of SPM was updated to require 4 years of follow-up from date the last subject enrolled in order to concur with the 4-year follow-up of safety and efficacy.

1. The SPM follow-up was extended from 4 to 5 years after last subject enrolled, until the time 100% of patients died, are lost to follow-up or have withdrawn consent, whichever comes first. (The efficacy follow-up was to remained unchanged at 4 years.)