A phase II pharmacodynamic study of pyrazoloacridine in patients with metastatic colorectal cancer

Purpose: To perform a phase II trial of pyrazoloacridine (PZA), a novel DNA intercalator, in patients with metastatic colorectal carcinoma and no previous therapy. Methods: PZA was administered at a dose of 750 mg/m2 intravenously over 3 h every 21 days. Pharmacokinetic studies to determine PZA plasma concentrations were performed. Results: No responses were seen in 14 response-evaluable patients. Patients received a median of two cycles of PZA (range 1–6). Toxicity included neutropenia and neurologic side-effects, which were ≥ grade III in 73% and 14%, respectively. High plasma concentrations of PZA (Cmax) correlated with low neutrophil counts (P=0.04). Conclusions: PZA is inactive at this dose and schedule in colorectal cancer, and produces moderately severe toxicity.