Methods

Cohorts include patients with intermediate-1, intermediate-2, or high-risk myelodysplastic syndrome (MDS) who failed ≥4 cycles of prior treatment with a hypomethylating agent; relapsed/refractory (R/R), multiple myeloma (MM) who failed ≥2 lines of prior therapy, including a proteasome inhibitor and IMiD; or R/R non-Hodgkin lymphoma (NHL): primary mediastinal large B cell lymphoma (MLBCL), follicular lymphoma (FL), diffuse large B cell lymphoma (DLBCL), or any other PD-L1-positive NHL that failed, was ineligible for, or refused a stem cell transplant and R/R HL (not presented here). Key eligibility criteria: age ≥18 years; ECOG PS 0/1; measurable disease; adequate hematologic, renal, and hepatic function. Key exclusion criteria: immunosuppressive disorder, active autoimmune disease, active pneumonitis, prior anti-PD-1/anti-PD-L1 therapy, active CNS involvement, and prior allogeneic hematopoietic stem cell transplantation within 5 years). Pembrolizumab is given at 200 mg Q3W in patients enrolled under the last amendment. Treatment continues until disease progression or intolerable toxicity; clinically stable patients may continue treatment beyond radiographic or hematologic (MDS or MM) evidence of progression until confirmed in following assessment. The primary end point is objective response rate (ORR). Secondary objectives include duration of response, progression-free survival, overall survival, and association between PD-L1 expression and response. Target enrollment for DLBCL and FL cohorts is ~50 patients.