A first-in-human dose-escalation study of ME-143, a second generation NADH oxidase inhibitor, in patients with advanced solid tumors.

Background: ME-143, a second-generation tumor-specific NADH oxidase inhibitor, is broadly active against human cancers in vitro and in vivo. This first-in-human dose-escalation study evaluated the dose-limiting toxicities (DLTs), pharmacokinetics, safety, tolerability, and preliminary anti-tumor activity of ME-143 in patients with advanced solid tumors.

Methods: Patients with advanced solid tumors were treated in a 3 + 3 escalation design. ME-143 was administered via intravenous infusion on days 1, 8, and 15 of the first 28-day cycle, and weekly thereafter; the final cohort received twice-weekly treatment. Samples for pharmacokinetic analysis were collected during cycle 1. Treatment continued until disease progression or unacceptable toxicity.

Results: Eighteen patients were treated: 2.5 mg/kg (n = 3); 5 mg/kg (n = 3); 10 mg/kg (n = 3); 20 mg/kg (n = 6); 20 mg/kg twice-weekly (n = 3). There were no DLTs observed. Nearly all treatment-related toxicities were grade 1/2, specifically (all grades) nausea (22 %) and fatigue (17 %). Two patients experienced infusion reactions at the 20 mg/kg dose level, one of which was grade 4. Stable disease was documented in three patients with colorectal cancer, cholangiocarcinoma, and anal cancer. Pharmacokinetic exposures were linear and dose-dependent, with a half-life of approximately 5 h.

Conclusions: ME-143 was well-tolerated when administered intravenously at the maximally administered/recommended phase 2 dose of 20 mg/kg once weekly to patients with advanced solid tumors. Though limited clinical activity was observed with monotherapy, inhibitors of tumor-specific NADH oxidase such as ME-143 may derive their greatest benefit in combination with cytotoxic chemotherapy.