Inclusion Criteria:

          -  Have histologically confirmed endometrial carcinoma, cervical carcinoma or uterine
             sarcoma, refractory or persistent to chemotherapy or recurrent disease after at least
             one line of chemotherapy.

          -  Presence of an index lesion amenable to hypofractionated stereotactic radiotherapy

          -  At least one lesion outside the radiation field that can be followed by imaging for
             clinical response according to RECIST and irRC

          -  Be willing to provide tissue from a newly obtained core or excisional biopsy of a
             tumor lesion before and after radiotherapy if technically feasible.

          -  Have a performance status of 0 or 1 or 2 on the ECOG Performance Scale.

          -  Demonstrate adequate organ function

        Exclusion Criteria:

          -  Currently participating and receiving study therapy or has participated in a study of
             an investigational agent and received study therapy or used an investigational device
             within 4 weeks of the first dose of treatment.

          -  Prior treatment with anti-PD-1, anti-PD-L1, anti-PD-L2 agent

          -  Diagnosis of immunodeficiency or is receiving systemic steroid therapy or any other
             form of immunosuppressive therapy within 2 weeks prior to the first dose of trial
             treatment,

          -  Known history of active TB (Bacillus Tuberculosis), Human Immunodeficiency Virus
             (HIV), HTLV or syphilis,non-infectious pneumonitis, has active autoimmune disease.

          -  Has active central nervous system metastases and/or carcinomatous meningitis