Final Results of Phase I/II Study of Selinexor (SEL) with Sorafenib in Patients (pts) with Relapsed and/or Refractory (R/R) FLT3 Mutated Acute Myeloid Leukemia (AML)

Responses to FLT3-inhibitors are usually transient due to emergence of resistance through the acquisition of kinase domain point mutations and other non-mutational mechanisms. SEL is a potent first-in-class Selective Inhibitor of Nuclear Export/SINE™ that exerted marked cell killing of human and murine FLT3-mutant AML cells, including those with ITD, D835Y, ITD+Y842C or ITD+F691L mutations by modulating the cdk inhibitor p27 and anti-apoptotic Mcl-1. The combination of SEL+sorafenib had synergistic pro-apoptotic effects in FLT3-mutated AML cells by suppressing phosphorylation levels of FLT3 and its downstream signaling mediators ERK/AKT, and by inducing myeloid differentiation in ITD and D835 mutated cell lines.We designed a phase I/II trial of SEL with sorafenib for FLT3-ITD and/or -D835 R/R AML pts. In phase I, the primary objectives were to determine the maximum tolerated dose (MTD), the recommended phase 2 dose (RP2D), and dose-limiting toxicity (DLT) of the combination. In phase II, primary objectives included the rate of composite complete remission (CRc) defined as CR+CR with incomplete platelet recovery (CRp)+CR with incomplete count recovery (CRi) within 3 months (mos) of therapy initiation. Secondary objectives were safety and overall survival (OS). SEL was given orally twice a week for 3-weeks on and 1-week off in 28-day cycles and sorafenib was given continuously at a dose of 400mg twice daily from cycle 1 day 1 of SEL. In phase I, SEL dose was de-escalated ...
Source: Blood - Category: Hematology Authors: Tags: 616. Acute Myeloid Leukemia: Novel Therapy, excluding Transplantation: Poster I Source Type: research