Phase I Study of the Investigational NEDD8-Activating Enzyme Inhibitor Pevonedistat (TAK-924/MLN4924) in Patients with Advanced Solid Tumors.

Purpose: To determine the dose-limiting toxicities (DLTs) and maximum tolerated dose (MTD) of the investigational NEDD8-activating enzyme (NAE) inhibitor pevonedistat (TAK-924/MLN4924) and to investigate pevonedistat pharmacokinetics and pharmacodynamics in patients with advanced nonhematologic malignancies.
Experimental Design: Pevonedistat was administered via 60-minute intravenous infusion on days 1 to 5 (schedule A, n = 12), or days 1, 3, and 5 (schedules B, n = 17, and C, n = 19) of 21-day cycles. Schedule B included oral dexamethasone 8 mg before each pevonedistat dose. Dose escalation proceeded using a Bayesian continual reassessment method. Tumor response was assessed by RECIST 1.0.
Results: Schedule A MTD was 50 mg/m(2); based on the severity of observed hepatotoxicity, this schedule was discontinued. Schedules B and C MTDs were 50 and 67 mg/m(2), respectively. DLTs on both these schedules included hyperbilirubinemia and elevated aspartate aminotransferase. There were no grade ≥ 3 treatment-related serious adverse events reported on schedules B or C. Twenty-three (74%) evaluable patients on schedules B and C had stable disease. Intermittent dexamethasone use did not significantly influence pevonedistat pharmacokinetics. NAE inhibition by pevonedistat was demonstrated in multiple tumor types via IHC detection of pevonedistat-NEDD8 adduct and accumulation of Cullin-RING ligase substrates CDT1 and NRF2 in tumor biopsies.
Conclusions: Pevonedistat was generally well tolerated on a day 1, 3, 5 schedule every 3 weeks with an MTD between 50 mg/m(2) and 67 mg/m(2). DLTs were predominantly hepatic enzyme elevations. Pharmacodynamic studies demonstrated that pevonedistat inhibited NAE in tumors.
(©2015 American Association for Cancer Research.)