Phase 1 study of ARQ 761, a β-lapachone analog that promotes NQO1-mediated programmed cancer cell necrosis.

2517Background: NAD(P)H:quinone oxidoreductase 1 (NQO1) is a two-electron oxidoreductase expressed in multiple tumor types at levels 5- to 200-fold above normal tissue. ARQ761 is a β-lapachone hydroquinone analog that exploits the unique elevation of NQO1 found in solid tumors to cause tumor-specific cell death by eliciting a futile redox cycle generating high levels of reactive oxygen species and ultimately PARP1 hyperactivation-dependent cell death. Methods: 3+3 dose escalation study of 3 schedules (weekly, every other week, 2/3 weeks) of ARQ 761 as a 1-hr or 2-hr infusion. Eligible patients had refractory advanced solid tumors, ECOG 0-1, adequate organ function, and central venous access. Blood samples were analyzed for ARQ761 levels and NQO1 polymorphisms. Archival tumor tissue was analyzed for NQO1 staining intensity and prevalence. After 18 patients were analyzed, enrollment was restricted to patients with NQO1-positive tumors (defined as Histo-score ≥200). Results: A total of 42 patients were treat...