Safety and Efficacy Study of Pembrolizumab (MK-3475) as Monotherapy in the Adjuvant Treatment of Renal Cell Carcinoma Post Nephrectomy (MK-3475-564/KEYNOTE-564)

Inclusion Criteria:

   - Has histologically confirmed diagnosis of renal cell carcinoma (RCC) with clear cell
   component with or without sarcomatoid features

   - Female participants of childbearing potential must be willing to use an adequate
   method of contraception, for the course of the study through 120 days after the last
   dose of study treatment

   - Male participants of childbearing potential must agree to use an adequate method of
   contraception, starting with the first dose of study treatment through 120 days after
   the last dose of study treatment

   - Has intermediate-high risk, high risk, or M1 no evidence of disease (NED) RCC as
   defined by the following pathological tumor-node-metastasis and Fuhrman grading
   status:

      1. Intermediate-high risk RCC: pT2, Grade 4 or sarcomatoid, N0, M0; pT3, Any Grade,
      N0, M0

      2. High risk RCC: pT4, Any Grade N0, M0; pT Any stage, Any Grade, N+, M0

      3. M1 NED RCC participants who present not only with the primary kidney tumor but
      also solid, isolated, soft tissue metastases that can be completely resected at
      one of the following: the time of nephrectomy (synchronous) or, ≤1 year from
      nephrectomy (metachronous)

   - Has received no prior systemic therapy for advanced RCC

   - Has undergone a partial nephroprotective or radical complete nephrectomy (and complete
   resection of solid, isolated, soft tissue metastatic lesion(s) in M1 NED participants)
   with negative surgical margins

   - Must have undergone a nephrectomy and/or metastasectomy ≥28 days prior to signing
   informed consent and ≤12 weeks prior to randomization

   - Must be tumor-free as assessed by the Investigator and validated by either computed
   tomography (CT) or magnetic resonance imaging (MRI) scan of the brain and chest,
   abdomen, and pelvis and a bone scan ≤28 days from randomization

   - Must have provided adequate tissue per the following: Nephrectomy only: tissue from
   nephrectomy (required); Synchronous M1 NED: tissue from nephrectomy (required) AND,
   metastasectomy tissue (if available); Metachronous M1 NED: tissue from metastasectomy
   (required) AND, nephrectomy tissue (if available)

   - Has an Eastern Cooperative Oncology Group Performance Status (ECOG PS) score of 0 or 1

   - Has adequate organ function

Exclusion Criteria:

   - Has had major surgery, other than nephrectomy and/or resection of pre-existing
   metastases for M1 NED participants, within 12 weeks prior to randomization

   - Has received prior radiotherapy for RCC

   - Has pre-existing brain or bone metastatic lesions

   - Has residual thrombus post nephrectomy in the vena renalis or vena cava

   - Has a diagnosis of immunodeficiency or is receiving chronic systemic steroid therapy
   (in dosing exceeding 10 mg daily of prednisone equivalent) or any other form of
   immunosuppressive therapy within 7 days prior the first dose of study treatment

   - Has an active autoimmune disease that has required systemic treatment in past 2 years
   (i.e., with use of disease modifying agents, corticosteroids, or immunosuppressive
   drugs). Replacement therapy is allowed

   - Has a known additional malignancy that is progressing or required active treatment ≤3
   years ago. Exceptions include early-stage cancers (carcinoma in situ or Stage 1)
   treated with curative intent, basal cell carcinoma of the skin, squamous cell
   carcinoma of the skin, in situ cervical cancer, in situ prostate cancer, or in situ
   breast cancer that has undergone potentially curative therapy

   - Has a history of (non-infectious) pneumonitis that required steroids or has current
   pneumonitis

   - Has an active infection requiring systemic therapy

   - Has a history of, or is currently on, dialysis

   - Has a known history of human immunodeficiency virus (HIV) infection

   - Has known active hepatitis B or hepatitis C virus infection

   - Has a known history of active tuberculosis (Bacillus tuberculosis)

   - Has had a prior solid organ transplant

   - Has severe hypersensitivity (≥ Grade 3) to pembrolizumab and/or any of its excipients

   - Is pregnant or breastfeeding, or expecting to conceive or father children within the
   projected duration of the study, starting with the Screening visit through 120 days
   after the last dose of study treatment

   - Has received prior therapy with an anti-programmed cell death protein 1 (anti-PD-1),
   anti-programmed cell death-ligand 1 (anti-PD-L1), or anti-programmed cell death-ligand
   2 (anti-PD-L2) agent or with an agent directed to another co-inhibitory T-cell
   receptor (i.e., cytotoxic T-lymphocyte-associated protein 4 [CTLA-4], OX-40, CD137
   [tumor necrosis factor receptor superfamily member 9 (TNFRSF9)]) or has previously
   participated in a Merck pembrolizumab (MK-3475) clinical trial

   - Has received prior anticancer therapy, monoclonal antibody, chemotherapy, or an
   investigational agent or device within 4 weeks or 5 half-lives (whichever is longer)
   before first dose of study treatment or not recovered (i.e., must be ≤ Grade 1 or at
   Baseline) from AEs due to previously administered agents

   - Has received a live vaccine within 30 days prior to the first dose of study treatment

   - Is currently participating in or has participated in a study of an investigational
   agent or has used an investigational device within 4 weeks prior to the first dose of
   study treatment