Inclusion Criteria:

          -  Patients with selected histologically or cytologically confirmed advanced and/or
             metastatic solid tumors who are refractory to or intolerant of existing therapies
             known to provide clinical benefit for their condition.

          -  ECOG performance score 0-1. Patients with ECOG is 2 to be discussed with the sponsor's
             medical monitor to be agreed for inclusion.

          -  Estimated life expectancy of ≥3 months

          -  Washout periods: 4 weeks for chemotherapy, 4 weeks or 5 half-lives (whichever shorter)
             for biologic agents including immuno-oncology therapy and 4 weeks from major
             surgeries, definitive radiotherapy and 2 weeks after palliative radiotherapy

          -  At least one measurable lesion per iRECIST in a non-irradiated port. If in a
             previously irradiated port, must have demonstrated progression since best response to
             radiation therapy.

          -  Have fully recovered from previous treatment to grade ≤1 toxicity (excluding alopecia)
             or have stable grade 2 neuropathy

          -  Adequate organ system function

          -  Negative serum pregnancy test, if woman of child-bearing potential (WOCBP;
             non-childbearing is defined as greater than one year postmenopausal or surgically
             sterilized).

          -  Accessible tumor tissue available for fresh biopsy

        Exclusion Criteria:

          -  Key exclusion criteria (Part A and B)

               -  Patient with untreated CNS metastases and/or leptomeningeal carcinomatosis (see
                  list of all exclusion criteria for details)

               -  Known additional malignancy that is progressing and/or requires active treatment.

               -  Prior exposure to drugs that are agonists of IL-2- or IL-15-like but not limited
                  to rhIL-15 (NCI), ALT-803 (ALTOR), NKTR-214 (Nektar)

               -  History of and current interstitial lung disease or fibrosis and pneumonitis;
                  patients with clinically significant or oxygen requiring COPD or any chronic
                  inflammatory disease (sarcoidosis etc.)

               -  Has received a live vaccine within 30 days of planned start of study therapy (see
                  list of all exclusion criteria for details)

               -  Absolute WBC count ≤ 2.0 ×109/L;

               -  ALC ≤0.5×109/L

               -  Absolute neutrophil count ≤1.0 ×109/L

               -  Platelet count ≤100×109/L

               -  Pregnant or breastfeeding women

               -  Any active autoimmune disease or a documented history of autoimmune disease,
                  poorly controlled asthma, or history of syndrome that required systemic steroids
                  (except the allowed doses) or immunosuppressive medications, except for patients
                  with vitiligo or resolved childhood asthma/atopy (see list of all exclusion
                  criteria for details)

               -  Specific co-morbidities (see list of all exclusion criteria for details)

               -  Is hypersensitive to any of the ingredients of pembrolizumab drug product
                  (KeytrudaTM)

               -  History of solid organ transplantation or hematopoietic stem cell transplantation