1. Addition of an exclusion criterion : Patients with a history of PML cannot be included in the study. The exclusion criterion "Prior history of Progressive Multifocal Leukoencephalopathy (PML) is added. - 2 Addition of a neurological examination during clinical examinations A neurological examination must be performed at every clinical examination, during the treatment and follow-up phases, in order to detect any neurological signs suggestive of neurological signs suggestive of potential PML. - 3 Indications on what to do if PML is suspected: symptoms, diagnosis, treatment with anti-CD20 drugs In the event of symptoms suggestive of PML, investigations should be carried out: consultation with a neurologist, brain MRI, testing for JC virus in cerebrospinal fluid, etc. cerebro-spinal fluid... Treatment with Rituximab or Obinutuzumab should be suspended during these investigations, and stopped permanently if the diagnosis of PML is confirmed.

- For biological studies, the theoretical sampling time "C1J8 1h after end of infusion" has been changed to "C1J8 just after end of infusion". - Exclusion criterion 8 has been modified to include patients with a history of non-melanoma skin tumours (basal cell carcinoma or squamous cell carcinoma of the skin) or surgically removed carcinoma of any grade 0 (in situ) in phase I, which does not include maintenance treatment with lenalidomide. - Following recommendations made by the study's DSMC at the organizational meeting, an electrocardiogram was added to the list of tests to be performed during patient screening. - Certain clarifications have been made concerning the rules for reporting adverse events

- The recommended lenalidomide dose of 20 mg for phase II has been added. - The doses of GA101 and lenalidomide for the two years of maintenance have been reformulated. - Corrections have been made to the abstract to reflect the content of the protocol (inclusion criteria, DLT definitions and prophylaxis). - AE and SAE deferrals have been added or clarified for each period. The NCI CTCAE version has been specified (version 4.03). - Following Roche's recommendations in a February DIL, prophylaxis treatments have been adapted. The dose of paracetamol is now 1000mg, and that of antihistamines such as diphenhydramine hydrochloride 100mg. Recommendations have been added for patients with pre-existing heart and lung disease. BSA calculation and B symptom collection were added to the baseline. It was specified that biological analyses could be performed. - During treatment, times for physical and neurological examinations and vital signs were clarified. Weight and BSA were collected only for assessments. CBC was maintained weekly for the 1st cycle, on the 1st day of each cycle for the induction period and at each visit for treatments during maintenance. All other CBCs were eliminated. Optional biological tests were added. - For assessments, appointment "windows" have been specified: for cycle 3 between I C3J21 and C3J28; for cycle 6 between C6J22 and C6J28. Assessments every 6 months during the maintenance period and in the event of premature discharge.- For assessments, only weight (without BSA) will be requested. PET scans are mandatory at the end of cycles 3 and 6 and at the end of treatment, but optional during maintenance. - During the maintenance period, it has been added that the PET scan is optional, bone marrow biopsy is compulsory every 6 months in the event of positive results at the previous assessment, response assessment must be carried out every 6 months as well as baseline assessments.- For biological studies, the theoretical sampling time "C1J8

o study duration shortened due to earlier inclusion than initially estimated o contraception of women for 18 months after GA101 treatment o withdrawal of the planned 20-patient efficacy/safety analysis, since a DSMC is planned every 6 months. o updated GA101 data.

The purpose of this amendment is to present GALEN's ancillary study: GALEN-IM.GALEN-IM is an exploratory, open-label, multicenter immunoPET ancillary study involving 30 GALEN patients with histologically confirmed CD20-positive follicular lymphoma.After signing specific information and consent documents, these patients will receive 0.6 MBq/kg (36-54 MBq) of 89Zr-obinutuzumab, in addition to the 1000 mg dose of obinutuzumab planned in the GALEN study, on Cycle 1 J8 and/or Cycle 2 J1.This administration will enable us to determine the tissue concentration of obinutuzumab in the tumor and in the main organs of interest, and to generate a PK model of obinutuzumab. Secondly, it will enable us to define patient radiation exposure, compare obinutuzumab concentration-time profiles in tumor and normal organs, correlate tissue and plasma PK with tumor burden, and evaluate the 89Zr-obinutuzumab uptake model.

Addition of a cohort of 100 previously untreated follicular lymphoma patients. Addition of biological studies adapted to this new cohort of 100 patients with previously untreated follicular lymphoma. Addition of biological studies to search for correlations between transcriptomic profile (GCvs ABC) and response to treatment for patients with relapsed or refractory diffuse large relapsed or refractory diffuse large B-cell lymphoma (DLBCL) already included in the phase 2 aggressive lymphoma cohort. Update of the Pregnancy Prevention Plan linked to lenalidomide treatment.

We would therefore like to complete the enrolment of cohort 3 without offering the GALEN-IM study to patients, to enable analysis of the 100 patients as planned in the protocol, and to add a cohort of 15 patients with 1st-line Follicular Lymphoma solely for the GALEN-IM study (cohort 4). These 15 patients will receive exactly the same treatment as the GALEN patients, with one or two additional doses of 89Zr-obinutuzumab. The data collected will meet the objectives of the GALEN-IM study alone, and will not be included in the analysis of the GALEN study.

The changes mainly concern the ancillary immunoPET exploratory study. It was initially planned that each patient would receive 0.6 MBq/kg (36-54 MBq) of 89Zr-obinutuzumab, in addition to the GALEN dose. the 1000 mg dose of obinutuzumab planned in the GALEN study, on Cycle 1 D8 and/or Cycle Cycle 2 D1. The first 6 patients finally received a fixed dose of 37 MBq on Cycle 1 D8 and Cycle Cycle 2 J1; subsequent patients will receive the same dose. Analysis of the results obtained from the first six patients shows that immunoPET scans scans performed on Cycle 1 Day 8 appear to be more informative than those performed on Cycle 2 Day 1. The experts therefore decided, for the remaining 9 patients, to carry out a single injection of 89Zr-obinutuzumab at Cycle Cycle 1 Day 8.