Phase 0- Pilot Study of Pembrolizumab on Immune Cells in Patient With Refractory Acute Myeloid Leukemia

Inclusion Criteria: 1. Be willing and able to provide written informed consent/assent for the trial. 2. Be 18 years of age on the day of signing informed consent. 3. Patients with newly diagnosed AML based on the World Health Organization classification (21) who have persistent leukemia after a course or more of treatment with induction chemotherapy (the diagnosis of persistent disease, which is defined as \>10% blasts by evaluation of bone marrow biopsy or bone marrow aspirate). 4. Left ventricular ejection fraction (LVEF) ≥ 45% 5. Have a performance status of 0 or 1 on the ECOG Performance Scale. 6. Demonstrate adequate organ function, all screening labs should be performed within 10 days of treatment initiation. 7. Female subject of childbearing potential should have a negative urine or serum pregnancy within 72 hours prior to receiving the first dose of study medication. If the urine test is positive or cannot be confirmed as negative, a serum pregnancy test will be required. 8. Female subjects of childbearing potential must be willing to use an adequate method of contraception- Contraception, for the course of the study through 120 days after the last dose of study medication. 9. Male subjects of childbearing potential must agree to use an adequate method of contraception- Contraception, starting with the first dose of study therapy through 120 days after the last dose of study therapy. Exclusion Criteria: 1. Has a diagnosis of Acute Promyelocytic Leukemia (APL) as defined by the World Health Organization 2. Relapsed acute myeloid leukemia 3. Bi-lineage or bi-phenotypic leukemias 4. Prior use of clofarabine or fludarabine 5. Previous allogeneic or autologous hematopoietic cell transplantation or solid organ transplantation 6. Is currently participating in 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. 7. Has a diagnosis of immunodeficiency or is receiving systemic steroid therapy or any other form of immunosuppressive therapy within 7 days prior to the first dose of trial treatment. 8. Has a known history of active TB (Bacillus Tuberculosis) 9. Hypersensitivity to pembrolizumab or any of its excipients. 10. Has had a prior anti-cancer monoclonal antibody (mAb) within 4 weeks prior to study Day 1 or who has not recovered (i.e., ≤ Grade 1 or at baseline) from adverse events due to agents administered more than 4 weeks earlier. 11. Has had prior chemotherapy, targeted small molecule therapy, or radiation therapy within 2 weeks prior to study Day 1 or who has not recovered (i.e., ≤ Grade 1 or at baseline) from adverse events due to a previously administered agent. 12. Concurrent active malignancy; exceptions include patients who have been disease free for 5 years, patients with a history of completely resected non-melanoma skin cancer or successfully treated in situ carcinoma, or patients with another malignancy that is indolent or definitively treated. 13. Has known active central nervous system (CNS) metastases and/or carcinomatous meningitis and/or has known active central nervous system (CNS) leukemia involvement. 14. Has active autoimmune disease that has required systemic treatment in the past 2 years (i.e. with use of disease modifying agents, corticosteroids or immunosuppressive drugs). Replacement therapy (eg., thyroxine, insulin, or physiologic corticosteroid replacement therapy for adrenal or pituitary insufficiency, etc.) is not considered a form of systemic treatment. 15. Has a history of (non-infectious) pneumonitis that required steroids or current pneumonitis. 16. Has a history or current evidence of any condition, therapy, or laboratory abnormality that might confound the results of the trial, interfere with the subject's participation for the full duration of the trial, or is not in the best interest of the subject to participate, in the opinion of the treating investigator. 17. Has known psychiatric or substance abuse disorders that would interfere with cooperation with the requirements of the trial. 18. Is pregnant or breastfeeding, or expecting to conceive or father children within the projected duration of the trial, starting with the pre-screening or screening visit through 120 days after the last dose of trial treatment. 19. Has received prior therapy with an anti-PD-1, anti-PD-L1, or anti-PD-L2 agent. 20. Has a known history of Human Immunodeficiency Virus (HIV) (HIV 1/2 antibodies). 21. Has known active Hepatitis B or Hepatitis C. 22. Has received a live vaccine within 30 days of planned start of study therapy.