Platelet count >= ,/mcL Platelet count > ,/mcl Platelet count > k/mcL Platelet count > , cells/mcL Platelet count >= ,/mcL Platelet count >= ,/mcL Platelets ?,/mcL (non-transfused platelet count) Platelet count >= ,/mcL Platelet count >= ,/mcL, within days of starting therapy Platelet < ,/mcL Platelet count >= k/mcl, obtained within days prior to first study treatment Thrombocytosis defined as platelet count > ,,/mcL Platelet >= , / mcL Platelet count >= /mcL Platelet count >/=, cells/mcL, or >/=, cells/mcL if more than % bone marrow involvement (Cohorts A, B, D, E, F) Platelet count >= ,/mcL PHASE II: Platelet count >= ,/mcL Platelet count >= ,/mcL Platelet count >= ,/mcL Platelet > , mcL Platelet count < K/mcL REGISTRATION TO TREATMENT (STEP ): Platelet count >= , /mcL, within days prior to first dose of pembrolizumab REGISTRATION TO TREATMENT (STEP ): Platelet count >= , /mcL, within days prior to first dose of pembrolizumab Platelet count > ,/mcL Platelet count > ,/mcL Platelet count >= , cells/mcL Platelet count < K/mcL at time of enrollment Platelet count > , cells/mcL ( ^/L) Platelet count >= ,/mcL Platelet count >= ,/mcl Platelet count >= K/mcL Platelet count >= ,/mcL Platelet count >= ,/mcL Platelet count >= ,/mcl Platelet count of at least , per mcL Platelet count >= ,/mcL Most recent platelet count prior to surgery < ,/mcl Platelet count > ,/mcL Thrombocytopenia:\r\n* Defined as platelet count < ,/mcL\r\n* The patient will have had at least complete blood counts (CBC) with platelet counts < ,/mcL separated by at least weeks, and no platelet count >= ,/mcL in the prior week period, despite () delay or () modification of chemotherapeutic regimen\r\n* A platelet count of > ,/mcL, that follows within days of a platelet transfusion, will not make the patient ineligible, as long as one or more subsequent platelet counts confirms thrombocytopenia (< ,/mcL)\r\n* Patients have undergone bone marrow aspirate and biopsy, or peripheral blood test in the prior months, without evidence of leukemia or myelodysplasia by fluorescent in situ-hybridization (FISH)\r\n* Dysplastic changes, based on morphology only, will not exclude the patient if FISH panel for myelodysplastic syndrome (MDS) is normal Platelet count >= ,/mcL Platelet count >= ,/mcL Platelet count <,/mcL.