Study of Azacitidine in Combination With Pembrolizumab in R/R AML Patients and in Newly Diagnosed Older Patients

Acute myeloid leukemia (AML) remains a therapeutic challenge. Although 60-80% of newly diagnosed patients with AML respond to induction chemotherapy, the relapse rate remains high (40%-50%) even after allogeneic stem cell transplant (alloHSCT). Data suggests that epigenetic therapy with azacitidine combined with blockade of PD-1/PD-L1 pathway is a rational therapeutic approach both in newly diagnosed older patients and those with relapsed and refractory AML. Furthermore, recent data suggest that the addition of PD-1 blockade (nivolumab) to azacitidine in patients with AML who have previously failed hypomethylating agents may induce responses in up to 20% patients We plan to examine two AML patient cohorts: Cohort 1: relapsed/refractory AML. Cohort 2: newly diagnosed AML in older patients (≥65 years) not candidates for induction chemotherapy. Azacitidine and pembrolizumab have distinct mechanisms of action with no common overlapping toxicities; however, as azacitidine and pembrolizumab have not been tested previously in combination in AML patients, we plan to start enrollment with Cohort 1 (a safety run-in phase) and include only relapsed/refractory AML patients excluding those relapsing after allogeneic hematopoietic stem cell transplant (alloHSCT). The primary objective of the run in safety phase would be to determine the safe and tolerable dose/schedule of azacitidine and pembrolizumab in patients with AML. We will perform safety run in phase only in Cohort 1 as Cohort 2 patients would be expected to have a same or better tolerability given that they are not heavily pretreated