['mesothelioma']
['nivolumab', 'nivolumab + ipilimumab']

        Inclusion Criteria:

          1. Histologically proved diagnosis of unresectable malignant pleural Mesothelioma (MPM)

          2. Available (archival and/or fresh) pathological samples for centralized PD-L1
             expression assessment by immunohistochemistry

          3. Age ≥ 18 years old; male and female

          4. ECOG Performance status 0-1

          5. Weight loss < 10% during last 3 months

          6. Life expectancy > 12 weeks

          7. Documented progression of the MPM, assessed by computed tomography (CT) -Scan.

          8. Measurable disease, defined as at least 1 lesion (measurable) that can be accurately
             assessed at baseline by CT-Scan and is suitable for repeated assessment using modified
             Response Evaluation Criteria in Solid Tumors [RECIST] for pleural mesothelioma (Byrne
             2004; Therasse 2006).

          9. Previous treatment by 1 or 2 systemic chemotherapy lines (1 line of chemotherapy
             considered if the patient received ≥2 cycles of this chemotherapy), including at least
             one line with pemetrexed in combination with platinum agent (i.e. "gold standard
             chemotherapy in MPM; triplet including bevacizumab also accepted)

         10. Written informed consent

         11. Patients must have adequate organ function : creatinine clearance > 50 mL/min
             (Cockcroft formula), Neutrophiles count > 1500/mm3; Platelets > 100 000/mm3 ;
             Hemoglobin > 9 g/dL; hepatic enzymes < 3N with total bilirubin ≤ 1.5 × ULN (upper
             limit of normal) except subjects with documented Gilbert's syndrome (≤ 5 × ULN) or
             liver metastasis, who must have a baseline total bilirubin ≤ 3.0 mg/dL

         12. Recovered from all toxicities associated with prior treatment, to acceptable baseline
             status, or a National Cancer Institute Common Terminology Criteria for Adverse Events
             (NCI CTCAE v4.0) Grade of 0 or 1, except for toxicities not considered a safety risk,
             such as alopecia or vitiligo

         13. Females of childbearing potential who are sexually active with a nonsterilized male
             partner must use a highly effective method of contraception for 28 days prior to the
             first dose of investigational product, and must agree to continue using such
             precautions for 6 months after the final dose of investigational product; cessation of
             contraception after this point should be discussed with a responsible physician.
             Periodic abstinence, the rhythm method, and the withdrawal method are not acceptable
             methods of contraception. They must also refrain from egg cell donation for 6 months
             after the final dose of investigational product. Men receiving nivolumab and who are
             sexually active with women of childbearing potential will be instructed to adhere to
             contraception for a period of 31 weeks after the last dose of nivolumab.

        Exclusion Criteria:

          1. Patients with primitive peritoneal, pericardial, testis or tunica vaginalis
             mesothelioma

          2. Patients with a recent history of other malignancies except adequately treated
             non-melanoma skin cancer, and curatively treated in-situ cancer. Patients with
             prostate adenocarcinoma diagnosed less than 5 years could be included in case of
             localized prostate cancer with good outcome according the Amico classification: ≤ T2a
             and Gleason Score ≤6 and PSA blood level ≤10 ng/ml, and treated with curative intent
             (surgery or radiotherapy) without chemotherapy. Patients with history of solid tumors,
             including adenocarcinoma, treated with curative intent and without any evidence of
             disease >5 years can be included as well.

          3. Brain metastasis, except if surgically resected or treated with stereotaxic
             radiotherapy with no evolution within the 3 months before inclusion, and asymptomatic
             patient

          4. History of primary immunodeficiency, history of organ transplant that requires
             therapeutic immunosuppression and the use of immunosuppressive agents within 28 days
             of randomization or a prior history of severe (grade 3 or 4) immune mediated toxicity
             from other immune therapy.

          5. Subjects with a condition requiring systemic treatment with either corticosteroids (>
             10 mg daily prednisone equivalent) or other immunosuppressive medications within 14
             days of randomization. Intranasal/inhaled or topical steroids, and adrenal replacement
             steroid doses ≤ 10 mg daily prednisone equivalent, are permitted in the absence of
             active autoimmune disease.

          6. Live attenuated vaccination administered within 30 days prior to randomization.

          7. Known history of interstitial lung disease (asbestosis…) or CT-scan signs of
             interstitial lung disease.

          8. Subjects with an active, known or suspected autoimmune disease, including systemic
             lupus erythematosis or Wegener's granulomatosis. Subjects with type I diabetes
             mellitis, or hypothyroidism only requiring hormone replacement, or skin disorders
             (such as vitiligo, psoriasis, or alopecia) not requiring systemic treatment, are
             permitted to enroll.

          9. Active or history of inflammatory bowel disease (eg, diverticulitis, colitis,
             Crohn's), irritable bowel disease, celiac disease or other serious gastrointestinal
             chronic conditions associated with diarrhea. Note that diverticulosis is permitted.

         10. Patients with active or uncontrolled infections or with serious illnesses or medical
             conditions which would not permit the patient to be managed according to the protocol.
             This includes but is not limited to:

               -  known prior history of active tuberculosis-disease;

               -  known acute or chronic B or C hepatitis by serological evaluation. Patients with
                  serological sequelae of hepatitis (antibodies test serologically positive for
                  virus) without hepatitis could be included.

               -  known Human immunodeficiency virus infection.

         11. Prior treatment with an anti-PD-1, anti-PD-L1, anti-PD-L2, anti-CTLA-4 antibody, or
             any other antibody or drug specifically targeting T-cell co-stimulation or checkpoint
             pathways

         12. The last dose of prior chemotherapy or radiation therapy (with the exception of
             palliative radiotherapy) was received less than 3 weeks prior to randomization
      