Renal Adjuvant MultiPle Arm Randomised Trial

Inclusion Criteria: 1. Histologically proven RCC (all cell types of RCC are eligible, except for pure oncocytoma, collecting duct, medullary and transitional cell cancer \[TCC\]); no evidence of residual macroscopic disease on post-operative CT scan after resection of RCC. Patients with treated bilateral synchronous RCCs are eligible. 2. At the start of recruitment patients with Leibovich score 3-11 will be eligible for randomisation. MRC CTU at UCL will monitor accrual and stop recruiting intermediate risk patients (Leibovich Score 3-5) after three years or when intermediate risk patients contribute 25% of the total accrual target, whichever is earlier. Recruitment of patients with Leibovich Score 6 11 will continue until the accrual target is reached. 3. Patients should have had surgery at least 28 days but no more than 91 days prior to their randomisation date. 4. Post-operative scans should be performed within 28 days prior to randomisation. 5. Patients with microscopically positive resection margins after radical nephrectomy at the nephrectomy bed, renal vein or inferior vena cava are eligible provided the post-operative CT scan shows no evidence of residual macroscopic disease. 6. WHO Performance Status 0 or 1. 7. Patient has archival FFPE pathology tissue available, and agrees to provide at least one sample (FFPE tumour block from nephrectomy, or a minimum of 10 unstained slides), as well as a baseline EDTA blood sample for future translational research). 8. Adequate normal organ and marrow function 1. Haemoglobin ≥9.0g/dL (transfusions will be allowed within 2 weeks prior to randomisation in order to achieve the entry criteria). 2. Absolute neutrophil count (ANC) ≥1.5 x 109/L (≥1500 per mm3). 3. Platelet count ≥100 x 109 (≥100,000 per mm3). 4. Bilirubin ≤1.5 x ULN (This will not apply to subjects with confirmed Gilbert's syndrome (i.e., persistent or recurrent hyperbilirubinemia that is predominantly unconjugated in the absence of haemolysis or hepatic pathology), who will be allowed only in consultation with their physician). 5. AST/ALT ≤2.5 x ULN. 6. Calculated Creatinine Clearance level \>40mL/min by Cockcroft Gault formula (using actual body weight). 9. 12-lead ECG on which QTcF must be \<450 ms. In case of clinically significant ECG abnormalities, including a QTcF value ≥450 ms, two additional 12-lead ECGs should be obtained over a brief period (e.g., 30 minutes) to confirm the finding. Patients are only eligible if a QTcF of \<450ms is confirmed 10. Subjects must be ≥18 years of age. 11. Written informed consent obtained from the patient. 12. Both men and women enrolled in this trial must be in agreement with trial policy on contraception during the treatment phase of the study and 6 months afterwards. Egg donation, sperm donation and breastfeeding must be avoided. 13. Evidence of post-menopausal status or negative serum HCG pregnancy test for female pre menopausal patients. Women will be considered post-menopausal if they have been amenorrhoeic for 12 months without an alternative medical cause. The following age specific requirements apply: 1. Women \<50 years of age will be considered post-menopausal if they have been amenorrhoeic for 12 months or more following cessation of exogenous hormonal treatments and if they have luteinising hormone and follicle-stimulating hormone levels in the post-menopausal range for the institution or underwent surgical sterilisation (bilateral oophorectomy or hysterectomy). 2. Women ≥50 years of age will be considered post-menopausal if they have been amenorrhoeic for 12 months or more following cessation of all exogenous hormonal treatments, had radiation-induced menopause with last menses \>1 year ago, had chemotherapy induced menopause with last menses \>1 year ago, or underwent surgical sterilisation (bilateral oophorectomy, bilateral salpingectomy, or hysterectomy). Exclusion Criteria: 1. Previous diagnosis of RCC. 2. Metastatic or macroscopic residual disease. 3. Patients with positive resection margins after partial nephrectomy. 4. Patients with a single pulmonary nodule ≥5mm diameter are not eligible unless the nodule has had a definite benign diagnosis. Patients with multiple small, less than 5 mm nodules may be eligible if nodules have been shown to be radiologically stable for at least 8 weeks. 5. Prior anticancer treatment (other than nephrectomy) for RCC. 6. Any unresolved toxicity NCI CTCAE Grade ≥2 from previous anticancer therapy with the exception of alopecia, vitiligo, and the laboratory values defined in the inclusion criteria 1. Patients with Grade ≥2 neuropathy will be evaluated on a case-by-case basis after consultation with the Study Physician. 2. Patients with irreversible toxicity not reasonably expected to be exacerbated by treatment with durvalumab or tremelimumab may be included only after consultation with the Study Physician. 7. History of another primary malignancy except for: 1. Malignancy treated with curative intent and with no known active disease ≥5 years before the first dose of IP and of low potential risk for recurrence. 2. Adequately treated non-melanoma skin cancer or lentigo maligna without evidence of disease. 3. Adequately treated carcinoma in situ without evidence of disease. 8. History of leptomeningeal carcinomatosis. 9. Concurrent enrolment in another clinical study, unless it is an observational (non interventional) clinical study or during the follow up period of an interventional study. 10. Major surgical procedure (as defined by the Investigator) within 28 days prior to the start of treatment. Local surgery of isolated lesions for palliative intent is acceptable. 11. Current or prior use of immunosuppressive medication within 14 days before the first dose of durvalumab or tremelimumab, with the exceptions of intranasal and inhaled corticosteroids or systemic corticosteroids at physiological doses, which are not to exceed 10 mg/day of predniso