A phase I trial of the human double minute 2 inhibitor (MK-8242) in patients with refractory/recurrent acute myelogenous leukemia (AML)

Objective: Evaluate safety/tolerability/efficacy of MK-8242 in subjects with refractory/recurrent AML. Methods: MK-8242 was dosed p.o. QD (30-250 mg) or BID (120-250 mg) for 7on/7off in 28-day cycle. Dosing was modified to 7on/14off, in 21-day cycle (210 or 300 mg BID). Results: 26 subjects enrolled (24 evaluable for response); 5/26 discontinued due to AEs. There were 7 deaths; 1 (fungal pneumonia due to marrow aplasia) possibly drug-related. With the 7on/7off regimen, 2 subjects had DLT5 in the 250 mg BID group (both bone marrow failure and prolonged cytopenia). With the 7on/14off, no DLTs were observed in 210 mg BID or 300 mg BID (doses >300 mg not tested). Best responses were: 1/24 PR (11 weeks; 120 mg QD, 7on/7off); 1/24 CRi (2 weeks;210 mg BID, 7on/14off); 1/24 morphologic leukemia-free state (4 weeks; 250 mg BID, 7on/7off). PK on Day7 at 210 mg BID revealed AUC(0-12) h 8.7 mu M.h,C-max 1.51 mu M (n = 5,T-max, 2-6 h), T-1/2 7.9 h, CLss/F 28.8 L/h, and V-SS/F 317 L. Conclusions: The 7on/14off regimen showed a more favorable safety profile; no MTD was established. Efficacy was seen using both regimens providing impetus for further study of HDM2 inhibitors in subjects with AML. (C) 2016 Elsevier Ltd. All rights reserved.