Phase II study of carboplatin and paclitaxel in advanced thymoma and thymic carcinoma.

PURPOSE: The purpose of this study was to evaluate the impact of carboplatin and paclitaxel in patients with advanced previously untreated thymoma and thymic carcinoma. PATIENTS AND METHODS: We conducted a prospective multicenter study in patients with unresectable thymoma (n = 21) or thymic carcinoma (n = 23). Patients were treated with carboplatin (area under the curve, 6) plus paclitaxel (225 mg/m(2)) every 3 weeks for a maximum of six cycles. The primary end point of this trial was to evaluate the objective response rate. RESULTS: From February 2001 through January 2008, 46 patients were enrolled. Thirteen patients had grade 4 or greater toxicity, mostly neutropenia. Using RECIST (Response Evaluation Criteria in Solid Tumors) 1.0 criteria, three complete responses (CRs) and six partial responses (PRs; objective response rate [ORR], 42.9%; 90% CI, 24.5% to 62.8%) were observed in the thymoma cohort; 10 patients had stable disease. For patients with thymic carcinoma, no CRs and five PRs (ORR, 21.7%; 90% CI, 9.0% to 40.4%) were observed; 12 patients had stable disease. Progression-free survival (PFS) was 16.7 (95% CI, 7.2 to 19.8) and 5.0 (95% CI, 3.0 to 8.3) months for thymoma and thymic carcinoma cohorts, respectively. To date, only seven patients (33.3%) with thymoma have died, compared with 16 patients (69.6%) with thymic carcinoma. Median survival time was 20.0 months (95% CI, 5.0 to 43.6 months) for patients with thymic carcinoma, but it has not been reached for patients with thymoma. CONCLUSION: Carboplatin plus paclitaxel has moderate clinical activity for patients with thymic malignancies, but this seems less than expected with anthracycline-based therapy. Patients with thymic carcinoma have poorer PFS and overall survival than patients with thymoma.

The effect of short- and long-term administration of verapamil on the disposition of cytochrome P450 3A and P-glycoprotein substrates.

BACKGROUND: Verapamil has the capability to inhibit and induce cytochrome P450 (CYP) 3A and P-glycoprotein (P-gp), but the relative extent and time course of these events in vivo are unclear. The effect of verapamil on CYP3A and P-gp activity was determined by examining its effect on its own disposition and on the disposition of fexofenadine, respectively. METHODS: Twelve healthy volunteers received 60 mg fexofenadine alone or after administration of 240 mg verapamil for 1, 10, and 38 days. The concentrations of verapamil and norverapamil, as well as their enantiomers, were quantified in serum by chiral HPLC. The concentrations of fexofenadine and its metabolite, azacyclonol, were quantified in serum and urine by liquid chromatography-mass spectrometry. RESULTS: The mean +/- SD maximum serum concentration (Cmax) and the area under the serum concentration-time curve of S-verapamil increased significantly on days 10 (40 +/- 21 ng/mL [P = .00044] and 433 +/- 316 ng.h.mL(-1) [P = .00047], respectively) and 38 (42 +/- 27 ng/mL [P = .019] and 433 +/- 256 ng.h.mL(-1) [P = .0081], respectively) compared with day 1 (21 +/- 12 ng/mL and 222 +/- 156 ng.h.mL(-1), respectively). The oral clearance (CLoral) of S-verapamil decreased significantly from 702 +/- 304 L/h on day 1 to 377 +/- 210 L/h on day 10 (P = .0029) and 449 +/- 419 L/h on day 38 (P = .05). Similar trends were observed for the Cmax and area under the serum concentration-time curve of R-verapamil and R- and S-norverapamil. All subjects showed a significant decrease in the CLoral of fexofenadine after a single dose (98 +/- 54 L/h, P = .00105) and 10-day dosing (102 +/- 40 L/h, P = .0011) of verapamil compared with the control value (156 +/- 69 L/h). The Cmax of fexofenadine was significantly increased by a single dose (165 +/- 42 ng/mL, P = .0005) and 10-day dosing (148 +/- 39 ng/mL, P = .0008) of verapamil compared with the control value (114 +/- 45 ng/mL). No significant difference in fexofenadine Cmax (P = .37) and CLoral (P = .43) was observed between the control values and values at 38 days of verapamil treatment. CONCLUSION: Verapamil inhibited CYP3A activity, with a maximum effect occurring within 10 days. Short-term administration of verapamil caused net inhibition of intestinal P-gp, whereas long-term administration of verapamil induced P-gp activity.