Effects of patupilone on the pharmacokinetics and pharmacodynamics of warfarin in patients with advanced malignancies: a phase I clinical trial.

Patupilone is a novel microtubule-targeting cytotoxic agent, which exerts its antitumor effect through microtubule stabilization. Pharmacokinetics, pharmacodynamics, and safety of warfarin when administered concomitantly with patupilone were investigated, and antitumor activity was assessed. This was a phase I, two-center, drug-drug interaction study. In the core phase of the study, treatment consisted of warfarin 20 mg orally (days 1 and 29) and patupilone 10 mg/m(2) i.v. (days 8 and 29). Patients benefiting from patupilone treatment continued treatment every 3 weeks (extension phase) until progression of disease, death, or unacceptable toxicity. Seventeen patients were treated (core phase, 17; extension, 9). The geometric mean ratios (comedication/monotherapy) for C(max) and area under the curve(0-168) of warfarin were near unity and their 90% confidence intervals were within the equivalence limits of 0.80 and 1.25. The half-life, plasma clearance, and International Normalized Ratio (INR) of warfarin were not affected by patupilone coadministration. The most common adverse events were diarrhea, nausea, vomiting, abdominal pain, anorexia, dehydration, asthenia, and peripheral neuropathy. Five (29.4%) patients experienced grade 3 study drug-related adverse events (diarrhea, 17.6%; increased INR, 11.8%; dehydration, 5.9%; and neutropenia, 5.9%). One patient with triple-negative breast cancer (estrogen receptor, progesterone receptor, and HER2/neu negative) had a partial response (35% decrease in tumor measurements by Response Evaluation Criteria in Solid Tumors), and 11 had stable disease for 6 weeks or more (≥12 weeks, 6 patients). The pharmacokinetics and pharmacodynamics of warfarin were not affected by patupilone coadministration, suggesting that patupilone has no clinically relevant effect on CYP2C9 metabolism. Patupilone showed antitumor activity in triple-negative breast cancer.

Phase I and pharmacokinetic study of imatinib mesylate in patients with advanced malignancies and varying degrees of liver dysfunction: a study by the National Cancer Institute Organ Dysfunction Working Group.

PURPOSE: To develop dosing guidelines and to evaluate the pharmacokinetics of imatinib in patients with liver dysfunction (LD). PATIENTS AND METHODS: Patients (N = 89) with varying solid tumors and liver function were stratified into four groups according to serum total bilirubin and AST and were treated with escalating doses of imatinib. Plasma and urine were assayed for concentrations of imatinib and its active metabolite, CGP74588. RESULTS: In the mild LD group, dose-limiting toxicity, specifically nausea/vomiting and fatigue, occurred in two patients at the 600 mg/d dose level. In the moderate and severe LD groups, the maximal dose evaluated was 300 mg/d. Grade 3 to 4 toxicities consisted primarily of liver function test elevations (24%), nausea/vomiting (10%), fatigue (6%), and edema (5%). After the first imatinib dose, the mean (+/- SD) dose-normalized areas under the plasma concentration-time curve from time 0 to infinity (AUC(0-infinity)) were 162 +/- 155, 171 +/- 72, 182 +/- 157, and 185 +/- 172 (mug/mL x h)/mg for normal, mild, moderate, and severe LD groups, respectively. Renal excretion of imatinib was less than 10% of the total dose in all groups. CONCLUSION: Imatinib exposure (as measured by the dose-normalized AUC) did not differ between patients with normal liver function and those with LD. The maximal recommended dose of imatinib for patients with mild LD is 500 mg/d. Dosing guidelines for patients with moderate and severe LD remain undetermined.

Phase I and pharmacokinetic study of imatinib mesylate in patients with advanced malignancies and varying degrees of renal dysfunction: a study by the National Cancer Institute Organ Dysfunction Working Group.

PURPOSE: This study was undertaken to determine the safety, dose-limiting toxicities (DLT), maximum-tolerated dose (MTD), and pharmacokinetics of imatinib in cancer patients with renal impairment and to develop dosing guidelines for imatinib in such patients. PATIENTS AND METHODS: Sixty adult patients with advanced solid tumors and varying renal function (normal, creatinine clearance [CrCL] >or= 60 mL/min; mild dysfunction, CrCL 40 to 59 mL/min; moderate dysfunction, CrCL 20 to 39 mL/min; and severe dysfunction, CrCL < 20 mL/min) received daily imatinib doses of 100 to 800 mg. Treatment cycles were 28 days long. RESULTS: The MTD was not reached for any group. DLTs occurred in two mild group patients (600 and 800 mg) and two moderate group patients (200 and 600 mg). Serious adverse events (SAEs) were more common in the renal dysfunction groups than in the normal group (P = .0096). There was no correlation between dose and SAEs in any group. No responses were observed. Several patients had prolonged stable disease. Imatinib exposure, expressed as dose-normalized imatinib area under the curve, was significantly greater in the mild and moderate groups than in the normal group. There was a positive correlation between serum alpha-1 acid glycoprotein (AGP) concentration and plasma imatinib, and an inverse correlation between plasma AGP concentration and imatinib clearance. Urinary excretion accounted for 3% to 5% of the daily imatinib dose. CONCLUSION: Daily imatinib doses up to 800 or 600 mg were well tolerated by patients with mild and moderate renal dysfunction, respectively, despite their having increased imatinib exposure.