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

BACKGROUND: NAD(P)H:quinone oxidoreductase 1 (NQO1) is a two-electron oxidoreductase expressed in multiple tumour types. ARQ 761 is a ß-lapachone (ß-lap) analogue that exploits the unique elevation of NQO1 found in solid tumours to cause tumour-specific cell death. METHODS: We performed a 3+3 dose escalation study of 3 schedules (weekly, every other week, 2/3 weeks) of ARQ 761 in patients with refractory advanced solid tumours. Tumour tissue was analysed for NQO1 expression. After 20 patients were analysed, enrolment was restricted to patients with NQO1-high tumours (H-score ≥ 200). RESULTS: A total of 42 patients were treated. Median number of prior lines of therapy was 4. Maximum tolerated dose was 390 mg/m2 as a 2-h infusion every other week. Dose-limiting toxicity was anaemia. The most common treatment-related adverse events were anaemia (79%), fatigue (45%), hypoxia (33%), nausea (17%), and vomiting (17%). Transient grade 3 hypoxia, reflecting possible methemoglobinaemia, occurred in 26% of patients. Among 32 evaluable patients, best response was stable disease (n = 12); 6 patients had tumour shrinkage. There was a trend towards improved efficacy in NQO1-high tumours (P = 0.06). CONCLUSIONS: ARQ 761 has modest single-agent activity, which appears associated with tumour NQO1 expression. Principal toxicities include anaemia and possible methemoglobinaemia.

Using a novel NQO1 bioactivatable drug, beta-lapachone (ARQ761), to enhance chemotherapeutic effects by metabolic modulation in pancreatic cancer.

Novel, tumor-selective therapies are needed to increase the survival rate of pancreatic cancer patients. K-Ras-mutant-driven NAD(P)H:quinone oxidoreductase 1 (NQO1) is over-expressed in pancreatic tumor versus associated normal tissue, while catalase expression is lowered compared to levels in associated normal pancreas tissue. ARQ761 undergoes a robust, futile redox cycle in NQO1+ cancer cells, producing massive hydrogen peroxide (H2 O2 ) levels; normal tissues are spared by low NQO1 and high catalase expression. DNA damage created by ARQ761 in pancreatic cancer cells "hyperactivates" PARP1, causing metabolic catastrophe and NAD ± keresis cell death. NQO1: catalase levels (high in tumor, low in normal tissue) are an attractive therapeutic window to treat pancreatic cancer. Based on a growing body of literature, we are leading a clinical trial to evaluate the combination of ARQ761 and chemotherapy in patients with pancreatic cancer.