Pilot Study of Pembrolizumab Treatment for Disease Relapse After Allogeneic Stem Cell Transplantation

Inclusion Criteria

• Male or female subjects with AML, MDS or mature B cell lymphomas that have relapsed following matched-related donor (MRD) or matched unrelated donor (MUD) (HLA-A -B -C -DR -DQ) alloSCT are eligible for enrollment
• Signed written informed consent
• Subjects must have signed and dated an IRB-approved written informed consent form in accordance with regulatory and institutional guidelines. This must be obtained before the performance of any protocol-related procedures that are not part of normal subject care.
• Subjects must be willing and able to comply with scheduled visits, treatment schedule, laboratory tests and other requirements of the study.
• Target population
• Subjects must be ≥ 18 years of age.
• Subjects must have an ECOG performance status of 0-1 (Appendix).
• Subjects have undergone alloSCT > 90 days prior to enrollment from a matched-related donor (MRD), matched-unrelated donor (MUD), cord blood donor, or haplo-identical and cord blood donor.
• There must be histological confirmation of relapse after alloSCT of any of the following diseases: any mature B cell lymphoma (cHL or NHL), AML or MDS.
• Subjects must be off of all immunosuppressive medications for a minimum of 2 weeks with the exception of physiologic doses of corticosteroids.
• Subjects with B cell lymphoma must have measurable disease, defined as at least 1 lesion that can be accurately measured in at least 2 dimensions with CT scan. Minimum measurement must be > 15 mm in the longest diameter and > 10 mm in the short axis.
• Subjects must not have had any prior investigational agents or devices within 4 weeks of beginning study drug
• Subjects must have no prior history of VOD
• Subjects must demonstrate adequate organ function as defined below. All screening labs should be performed within 10 days of treatment initiation.

Hematological Absolute neutrophil count (ANC) ≥ 500 /mcL Platelets ≥ 20,000 /mcL Hemoglobin ≥ 8 g/dL (RBC transfusions are OK)

Renal Serum creatinine OR Measured or calculated creatinine clearance (GFR can also be used in place of creatinine or CrCl) ≤ 1.5 X upper limit of normal (ULN) or

• 60 mL/min for subject with creatinine levels > 1.5 X institutional ULN

Hepatic Serum total bilirubin ≤ 1.5 X ULN or direct bilirubin ≤ ULN for subjects with total bilirubin levels > 1.5X ULN AST (SGOT) and ALT (SGPT) ≤ 2.5 X ULN Albumin ≥ 2.0 mg/dL

Coagulation International Normalized Ratio (INR) or Prothrombin Time (PT) ≤ 1.5 X ULN unless subject is receiving anticoagulant therapy, in which case, the PT/INR should be within therapeutic range for intended use. Activated Partial Thromboplastin Time (aPTT) ≤ 1.5 X ULN unless subject is receiving anticoagulant therapy, in which case, the PTT should be within therapeutic range for intended use.

*Creatinine clearance should be calculated per institutional standard.

• Female subjects of childbearing potential should have a negative urine or serum pregnancy test (β-hCG) within 72 hours prior to receiving the first dose of study medication.
• Female subjects with childbearing potential should be willing to use 2 methods of contraception, be surgically sterile, or abstain from heterosexual activity throughout the course of the study, until 120 days after the final dose of study medication. Subjects with childbearing potential are those who have not been surgically sterilized or have not been free from menses for > 1 year. Abstinence is acceptable if this is the established and preferred contraceptive method for the subject.
• Male subjects should agree to use an adequate method of contraception starting with the first dose of study medication until 120 days after the final dose of study medicine. Abstinence is acceptable if this is the established and preferred contraceptive method for the subject.

Exclusion Criteria

• 1. Target disease exclusions
• Subjects must not have known central nervous system involvement by disease (parenchymal, meningeal or ce