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Purpose: The relationship between the pharmacokinetics and effects of gefitinib in patients with epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer (NSCLC) is unknown. In this study, we examined the correlation between gefitinib plasma concentration and progression-free survival (PFS) in patients with two common types of EGFR mutations: a deletion in exon 19 and point mutations in exon 21 L858R.Methods: The retrospective analysis examined 40 patients who were administered 250 mg of gefitinib daily. All patients were diagnosed with and treated for advanced non-small cell lung carcinoma with sensitive EGFR mutations between January 2011 and November 2013 at Akita University Hospital, Akita, Japan. The 40 patients were divided into four groups by trough plasma concentration (high or low) and mutation type (exon 19 deletions or exon 21 L858R point mutations). PFS, response rate, and toxic effects were analyzed in all four groups.Results: After excluding 5 patients, the remaining 35 were successfully analyzed. For the patients with exon 19 deletions, there was no significant difference in PFS between the high and low plasma concentration groups (median survival: 12.0 vs. 17.0 months, P = 0.9548). In contrast, the PFS was significantly shorter for patients with exon 21 point mutations and low vs. high concentrations of gefitinib (median survival: 8.0 vs. 16.0 months, P < 0.05).Conclusions: The results suggest that low gefitinib plasma concentrations in patients with exon 21 L858R point mutations may be associated with shorter PFS in NSCLC patients. [ABSTRACT FROM AUTHOR]

Purpose: RPI.4610 (ANGIOZYME) is a chemically stabilized ribozyme targeting vascular endothelial growth factor receptor 1. The purpose of this study was to evaluate the safety and pharmacokinetics of RPI.4610 in combination with carboplatin and paclitaxel in patients with advanced solid tumors. Methods: The study used a sequential treatment design evaluating a single dose level for all three drugs: paclitaxel 175 mg m-² and carboplatin AUC=6 on day 1 of a 21-day cycle, and RPI.4610 100 mg m-² day-± beginning on day 8 and continuing daily thereafter. Pharmacokinetic samples were drawn on day 1 of courses 1 (chemotherapy alone) and 2 (chemotherapy+RPI.4610), and on day 8 of course 1 (RPI.4610 alone). Ratios were generated by comparing the pharmacokinetic parameters for the combination of carboplatin with paclitaxel when administered alone or together with RPI.4610. Results: Twelve patients were enrolled in this trial and received two to six courses of treatment each. The most common grade 3–4 toxicities were neutropenia (three patients), thrombocytopenia (three patients), pain (three patients), anemia (two patients) and fatigue (two patients). The ratio of the mean maximum plasma concentration (Cmax) for carboplatin when administered with paclitaxel alone versus when administered with paclitaxel and RPI.4610 was 1.07 (90% confidence interval, 0.77–1.37). Similarly, the ratio of the mean AUC0-last for carboplatin was 1.04 (0.73-1.35). For paclitaxel the ratio of the mean Cmax when administered with carboplatin alone versus with carboplatin and RPI.4610 was 1.17 (1.03–1.31), and the ratio of the mean AUC0-last was 1.17 (1.04–1.30). Objective tumor responses were observed and included one patient with a complete response (bladder cancer) and one patient with a partial response (esophageal cancer). Conclusions: These results indicate that RPI.4610, carboplatin, and paclitaxel can be administered safely in combination without substantial pharmacokinetic interactions. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the metabolic fate of UCN-01, a signal transduction inhibitor, blood and plasma concentrations, distribution, metabolism and excretion were investigated in rats and dogs after intravenous administration of [3H]UCN-01. Methods: The radioactivity in plasma, blood and tissues was measured after intravenous administration of UCN-01. In addition, the radioactivity excreted in bile, urine and feces was also determined. Results: The radioactivity in rat and dog plasma disappeared triphasically with terminal half-lives of 21.3 and 27.2 h, respectively. The ratios of the blood-to-plasma concentrations ranged from 0.82 to 1.13 in rats and 0.81 to 1.73 in dogs. From 0.5 to 4 h after giving [3H]UCN-01 to rats, the radioactivity in all tissues except the brain and testes was higher than in plasma. The highest concentration was observed in the lungs followed by the liver and kidneys. The radioactivity was mainly excreted in feces, reaching 96.0% of the radioactivity dose in rats and 78.4% in dogs up to 168 h after injection. Since the biliary excreted radioactivity was 67.2% over 48 h in bile duct-cannulated rats, most of the radioactivity excreted in feces was from biliary radioactivity. There were several metabolites in bile samples, but little UCN-01. Conclusions: UCN-01 is mainly eliminated by the liver, and there are high concentrations of radioactivity derived from [3H]UCN-01 in all tissues except the brain and testes. [ABSTRACT FROM AUTHOR]

Purpose: 7-Hydroxystaurosporine (UCN-01) is a potent protein kinase inhibitor and is being developed as a novel anticancer agent. We describe here its pharmacokinetics and pharmacodynamics in experimental animals. Methods: The pharmacokinetics of UCN-01 were studied following intravenous (i.v.) administration to mice, rats and dogs at doses of 1–9, 0.35–3.5 and 0.5 mg/kg, respectively. We also studied the pharmacodynamics of UCN-01 (9 mg/kg per day) during and after five consecutive i.v. administrations to nude mice bearing xenografted human pancreatic tumor cells (PSN-1). The concentrations of UCN-01 in plasma and tumor were measured by HPLC using a fluorescence detector. Results: UCN-01 in plasma after i.v. administration was eliminated biphasically in mice and rats, and triphasically in dogs. The elimination half-lives in mice, rats and dogs were 3.00–3.98, 4.02–4.46 and 11.6 h, respectively. The total clearance (Cltotal) values in mice, rats and dogs were high (1.93–2.64, 2.82–3.86 and 0.616 l/h per kg, respectively). The hepatic clearance (Clhepatic) in rats represented 54.0–81.3% of Cltotal. The volumes of distribution at steady-state in mice, rats and dogs were large (7.89–8.42, 13.0–16.9 and 6.09 l/kg, respectively). These pharmacokinetic parameters were dose-independent in mice and rats. UCN-01 produced significant inhibition of tumor growth during five consecutive i.v. administrations in mice bearing the xenografted PSN-1 cells, and the inhibitory effect continued for 3 days after the final administration. UCN-01 concentrations in tumor tissue were much higher than those in the plasma, and the ratio of tumor to plasma concentrations was about 500 at 24 h after five consecutive doses. Conclusions: The pharmacokinetic studies showed that UCN-01 has a high clearance and large distribution volume in various experimental animals, and its disposition is linear over the range of doses tested. The pharmacodynamic study showed that UCN-01 is distributed at much higher concentrations in tumor than those in plasma and that it significantly inhibits tumor growth. The high distribution of UCN-01 into tumor cells may contribute to the potent inhibition of tumor growth in vivo. [ABSTRACT FROM AUTHOR]