Yvonne Lassere

Phase II trial of uracil and tegafur plus oral leucovorin: an effective oral regimen in the treatment of metastatic colorectal carcinoma.

PURPOSE To determine the activity and evaluate the toxicity of uracil and tegafur in a 4:1 molar concentration (UFT; Taiho Pharmaceutical Ltd, Tokyo, Japan) plus oral calcium leucovorin in the treatment of patients with advanced colorectal carcinoma. PATIENTS AND METHODS Forty-five patients with advanced, bidimensionally measurable metastatic colorectal carcinoma were enrolled onto the trial. None of the patients had received prior chemotherapy or biologic therapy for advanced disease. Patients received either 350 or 300 mg/m2/d UFT plus 150 mg/d leucovorin administered orally in divided daily doses every 8 hours for 28 days followed by a 7-day rest period. Response was evaluated after two courses of therapy. RESULTS Eighteen patients (three treated at 350 mg/m2/d and 15 at 300 mg/m2/d) had partial responses, and one patient had a complete response (response rate, 42.2%; 95% confidence interval, 28% to 58%). Responses were observed in sites that included liver (n = 18), lung (n = 6), and bone (n = 1). Of seven patients who received 350 mg/m2 UFT, prolonged grade 3 diarrhea developed in five; this resulted in a reduction in the UFT starting dose to 300 mg/m2/d in the remaining 38 patients. Grade 1 or 2 toxic effects included diarrhea, nausea, vomiting, abdominal cramping, anorexia, fatigue, oral mucositis, excessive lacrimation, and rash. Among 38 patients who received the 300-mg/m2/d dose, grade 3 toxic reactions included diarrhea (n = 4), vomiting (n = 2), abdominal cramping (n = 1), and fatigue (n = 2). CONCLUSION UFT 300 mg/m2/d plus oral leucovorin 150 mg/d administered for 28 days demonstrated significant activity against metastatic colorectal carcinoma. This oral regimen was well tolerated and devoid of the neutropenia or significant oral mucositis that complicates intravenous schedules of fluorouracil (5-FU) plus leucovorin. The results of this clinical trial will serve as the basis for a randomized phase III study to compare this oral schedule of UFT plus leucovorin with intravenous 5-FU plus leucovorin to determine the relative efficacy, impact on quality of life, and cost of the two regimens.

Phase I study to determine the safety and pharmacokinetics of oral administration of TAS‐102 in patients with solid tumors

The purpose of the current study was to determine the maximum tolerated dose, dose‐limiting toxicities, pharmacokinetic profile, and recommended Phase II dose of oral administration of TAS‐102, a novel nucleoside formed by the combination of α,α,α‐trifluorothymidine (FTD) and a thymidine phosphorylase inhibitor (TPI: 5‐chloro‐6‐(2‐iminopyrrolidin‐1‐yl)methyl‐2,4(1H,3H)‐pyrimidinedione).

Phase II Study of Capecitabine in Patients With Fluorouracil-Resistant Metastatic Colorectal Carcinoma

PURPOSE Capecitabine is an oral fluoropyrimidine converted to fluourouracil (FU) preferentially in tumor tissue. It has proven clinical activity against colorectal cancer when used as first-line therapy. The objectives of this study were to assess the safety and efficacy of capecitabine in patients with metastatic colorectal carcinoma who progressed despite previous FU therapy. PATIENTS AND METHODS According to the group sequential analysis design of this study, accrual would stop if no responses were observed in the first 20 patients treated. If one or more objective responses were confirmed, the trial would be expanded. Patients received capecitabine 1,250 mg/m(2) twice a day for 14 days, every 3 weeks. Tumor lesions were assessed every 6 weeks, and patients were followed for survival every 3 months after completing treatment. RESULTS Twenty-three patients were enrolled onto the study; 22 fulfilled all the eligibility criteria. No objective responses were observed among the 22 eligible patients; 11 patients (50%) had stable disease for a median duration of 141 days (range, 88-289 days). The Kaplan-Meier estimate of median time to disease progression was 64 days (95% CI, 41 to 134 days). The median survival time estimate was 389 days (95% CI, 267 to 637 days). The most frequent treatment-related adverse events were hand-foot syndrome, diarrhea, and nausea or vomiting. There were no grade 4 toxicities and no treatment-related deaths. CONCLUSION Single-agent capecitabine in patients with metastatic colorectal carcinoma refractory to FU showed no objective responses and clinical benefit that was, at best, modest. The use of capecitabine in combination with other treatments in this patient population is under investigation.

Phase I Study of Preoperative Oral Uracil and Tegafur Plus Leucovorin and Radiation Therapy in Rectal Cancer

PURPOSE Preoperative combined-modality therapy for rectal cancer may allow for sphincter preservation, while decreasing recurrence rates and improving the overall prognosis. Oral chemotherapy with uracil and tegafur (UFT) plus leucovorin (LV) may reduce costs and complications associated with protracted infusions of fluorouracil. Our goal was to evaluate the safety of UFT plus LV combined with preoperative radiation and determine the maximum-tolerated dose (MTD) and dose-limiting toxicity (DLT) of UFT plus LV in this setting. PATIENTS AND METHODS Patients with tumor-node-metastasis stage II or III rectal cancer received escalating doses of UFT (starting at 250mg/m(2)/d, with 50-mg/m(2)/d increments between consecutive cohorts) and fixed doses of LV (90 mg/d). The UFT and LV combination was given 5 days per week concurrently with a 5-week course of preoperative radiation totaling 45 Gy (1.8 Gy/fraction). Surgery was performed 4 to 6 weeks after radiation and was followed by four 35-day cycles of fixed doses of UFT and LV (28 days of therapy each cycle). RESULTS Fifteen patients were treated, and 13 received the full preoperative chemotherapy. All planned radiation was delivered successfully. The MTD of UFT with radiation was 350 mg/m(2)/d with 90 mg/d of LV. Diarrhea was the DLT. Sphincter-preserving surgery was performed in 12 of 14 patients. One patient had progressive disease before surgery. Pathologic evaluation of 14 resected specimens showed a complete response in three cases. CONCLUSION Preoperative chemoradiation with oral UFT plus LV is feasible and well tolerated and should be further investigated.

PHASE I TRIALS OF URACIL-TEGAFUR (UFT) USING 5 AND 28 DAY ADMINISTRATION SCHEDULES : DEMONSTRATION OF SCHEDULE-DEPENDENT TOXICITIES

We conducted two consecutive phase I clinical trials to identify the qualitative and quantitative toxic effects of uracil-tegafur (UFT) [Taiho Pharmaceutical Co. Ltd, Tokyo, Japan; (BMS-200604) Bristol-Myers Squibb, Princeton, NJ] administered either on a 5 or 28 day schedule and to determine the phase II trial starting doses for both schedules. Nineteen patients were entered on the 5 day schedule and 23 patients were entered on the 28 day schedule; a minimum of three patients were entered at each dose level studied. In both phase I trials, the daily UFT dose was divided into three doses administered every 8 h. Dose levels examined with the 5 day schedule were 360, 720, 900 and subsequent de-escalation to 800 mg/m2/day. Dose levels studied with the 28 day schedule were 180, 360, 450 and subsequent de-escalation to 400 mg/m2/day. With the 5 day schedule, the dose-limiting toxicity (DLT) was granulo-cytopenia, with four of five patients experiencing grade 4 granulocytopenia at the 900 mg/m2/day dose level. With the 28 day schedule, the DLT was diarrhea, which was noted in three of eight patients treated at 400 mg/m2/day and in three of six patients treated at 450 mg/m2/day. At these dose levels, four of these patients required prolonged hospitalizations for their diarrhea. The toxic effects of UFT are schedule dependent, with marked differences in the toxic effect profile (neutropenia versus diarrhea). With the 5 day schedule, the phase II UFT starting dose is 800 mg/m2/day. On the 28 day schedule, the suggested phase II UFT starting dose is 360 mg/m2/day. Future clinical trials examining the combination of UFT plus oral folinic acid are being conducted to develop oral regimens of therapy for advanced colorectal carcinoma and adjuvant therapy for colon carcinoma.

Phase I and Pharmacokinetic Study of Exatecan Mesylate (DX-8951f): A Novel Camptothecin Analog

PURPOSE To determine the maximum-tolerated dose (MTD), dose-limiting toxicity (DLT), pharmacokinetic (PK) profile, and recommended phase II dose of Exatecan mesylate (DX-8951f) when administered as a 24-hour continuous infusion every 3 weeks to patients with solid tumors. PATIENTS AND METHODS Twenty-two patients with advanced solid tumors, all previously treated, and with performance status < or = 2, were entered. The starting dose of DX-8951f was 0.15 mg/m(2); the dose was escalated according to the modified continual reassessment method. The drug was administered until disease progression or until unacceptable toxic effects occurred. RESULTS Seven dose escalations were completed, and a total of 53 courses were delivered (median, two courses; range, one to eight courses) during the study. At doses 1.2 mg/m(2) and lower, toxicities were mostly grade 1, primarily hematologic. In the initial cohort of three patients treated at 2.4 mg/m(2), grade 2 hematologic toxicity was observed. Of the six additional patients entered at 2.4 mg/m(2), three had grade 3 or 4 granulocytopenia. At doses higher than 2.4 mg/m(2), DLT granulocytopenia was observed. Nonhematologic toxicities, including nausea, vomiting, diarrhea, fatigue, and alopecia, were mild to moderate. Neither complete nor partial responses were observed, but four patients had stable disease. The PK profile of DX-8951f seemed linear at the doses administered. The plasma clearance, total volume of distribution, and terminal elimination half-life were approximately 3 L/h, 40 L, and 14 hours, respectively. CONCLUSION The DLT of this DX-8951f schedule was granulocytopenia for minimally pretreated patients, and both granulocytopenia and thrombocytopenia for heavily pretreated patients. The MTD for both minimally and heavily pretreated patients was 2.4 mg/m(2). DX-8951f seems to have a linear PK profile on the basis of single-dose administration. The recommended phase II dose with this schedule is 2.4 mg/m(2) for minimally pretreated patients. A lower dose should be used for heavily pretreated patients.

Oral uracil and Ftorafur plus leucovorin: pharmacokinetics and toxicity in patients with metastatic cancer.

Purpose: To assess the pharmacokinetics of Ftorafur (tegafur, FT), 5-fluorouracil (5-FU), and uracil in 31 cancer patients who were enrolled in phase I studies of oral uracil and FT (UFT). The correlation between pharmacokinetic parameters and toxic effects of UFT was evaluated. Methods: Uracil and FT were orally administered in a 4:1 molar ratio at FT doses of 200–400 mg/m2 per day. Patients also received leucovorin at 150 mg/day. Daily doses were divided into three doses and administered at 8-h intervals for 28 consecutive days. Plasma FT concentrations were measured by high-performance liquid chromatography, and plasma 5-FU and uracil concentrations were determined using gas chromatography-mass spectrometry. National Institutes of Health Common Toxicity Criteria were used for assessment of toxicity. Results: The concentrations of FT, 5-FU, and uracil showed wide interpatient variations. Maximum plasma concentrations (Cpmax) of all three compounds were achieved in 0.3 to 4.0 h. At the various study doses, the terminal half-life (t1/2β) of FT ranged from 3.9 to 5.9 h, the area under the concentration-versus-time curve (AUC0–6h) ranged from 16,220 to 52,446 (ng/ml)h, the total clearance (ClT) ranged from 100 to 175 ml/min, and the steady-state volume of distribution (Vdss) ranged from 18.3 to 28.7 l. The 5-FU generated from FT had an apparent distribution half-life (t1/2α) and an apparent elimination half-life (t1/2β) of 0.3–1.3 h and 4.9–7.0 h, respectively. The AUC0–6h of 5-FU ranged from 120 to 325 (ng/ml)h. Uracil had a t1/2α of 0.2–0.5 h and the level quickly returned to the endogenous level. The AUC0–6h for uracil ranged from 605 to 3764 (ng/ml)h, the ClT ranged from 3225 to 7748 ml/min, and the Vdss ranged from 341 to 1354 l. The Cpmax and AUC0–6h of both FT and uracil were significantly correlated with FT doses (P-values of 0.0244 and 0.0112) and with uracil doses (P-values of 0.0346 and 0.0083), respectively. In addition to interpatient variations, intrapatient variations were also observed in six patients who had pharmacology studies done on days 1 and 26 ± 2 at the same study dose. We found that the repeated treatment with UFT caused cumulative increases in the values of Cpmax, Ctrough, and AUC0–6h of FT and 5-FU. The major toxic effects observed were diarrhea and nausea and vomiting. The occurrence of these toxic effects correlated significantly with the Cpmax and AUC0–6h of 5-FU. Conclusions: The pharmacology studies showed that FT and uracil were readily absorbed orally and that FT was rapidly converted to 5-FU. The preliminary findings suggest that determination of plasma levels of 5-FU after oral administration of UFT may help predict subsequent toxic effects.

Tegafur/uracil + calcium folinate in colorectal cancer: Double modulation of fluorouracil

The oral chemotherapeutic agent tegafur/uracil (UFT®) is the first of a new class of anticancer drugs called dihydropyrimidine dehydrogenase inhibitory fluoropyrimidines. Tegafur/uracil combines uracil with the fluorouracil prodrug tegafur in a 4: 1 molar ratio. Uracil competitively inhibits the degradation of fluorouracil, which results in the concentration of fluorouracil remaining at sustained levels in both plasma and tumour. Tegafur/uracil has been commercially available in Japan since 1983 and examined extensively in various tumours. Trials conducted in the US have focused on the combination of tegafur/uracil plus calcium folinate (calcium leucovorin) [ORZEL®]. Several phase I and II trials have evaluated the maximum tolerated dose, pharmacokinetics, efficacy, and safety of this combination in the treatment of colorectal cancer. Results have shown that tegafur/uracil at 300 mg/m2/day in divided doses given every 8 hours for 28 days provides prolonged exposure to fluorouracil. Furthermore, tegafur/uracil + calcium folinate is well tolerated, with dose-limiting toxicity manifesting as diarrhoea. Compared with intravenous fluorouracil plus folinic acid (leucovorin) regimens, tegafur/uracil + calcium folinate has similar efficacy with less toxicity and is more convenient because it is an oral regimen. Early studies have also shown potential cost savings because of fewer complications.

Phase I trial of combined irinotecan and oxaliplatin given every three weeks to patients with metastatic colorectal cancer

Background: Both irinotecan and oxaliplatin are active agents in the treatment of patients with metastatic colorectal cancer (MCC). There is a strong preclinical rationale for combining these two agents. We sought to determine the dose-limiting toxicity (DLT) and the maximum tolerated dose (MTD) of combined irinotecan and oxaliplatin given every three weeks. Methods: Cohorts of patients with MCC previously treated with 5-fluorouracil received escalating doses of irinotecan (150, 175, and 200 mg/m2) and a fixed dose of oxaliplatin (130 mg/m2), both given intravenously every 3 weeks. DLT was evaluated within the first course of treatment. Objective responses were evaluated every two courses and were confirmed at least four weeks later. Results: Fourteen patients were treated and evaluated for toxicity. The DLT was neutropenia, with or without fever, and delayed recovery of neutrophil counts was frequent (13 courses in six patients). Other toxic effects (peripheral neuropathy, nausea, vomiting, diarrhea, and fatigue) were mild to moderate. Among 13 patients evaluable for activity, four achieved partial responses and nine had stable disease. Conclusion: The combination of irinotecan and oxaliplatin is safe and apparently active in the treatment of MCC patients. The recommended dose for phase II studies is 175 mg/m2 irinotecan plus 130 mg/m2 oxaliplatin, given every 3 weeks. Neutropenia and delayed recovery of neutrophil counts are the predominant early toxicities with this schedule.

A phase II study of UFT with leucovorin administered as a twice daily schedule in the treatment of patients with metastatic colorectal cancer

Prolonged infusions have been shown to be safer and potentially more effective than bolus regimens of 5-fluorouracil (5-FU) as treatment for metastatic colorectal cancer (mCRC). However, infusional 5-FU requires central venous access and costly infusion pumps. Oral fluoropyrimidines enable longer exposures to 5-FU with increased convenience. Tegafur–uracil (UFT) with leucovorin (LV) given thrice daily has improved safety plus comparable survival and response rates to bolus 5-FU/LV. We conducted a phase II clinical study in 98 patients with mCRC to evaluate if UFT with LV given twice daily provided comparable time to progression (TTP), efficacy and tolerability to that reported for thrice daily in two phase III clinical studies. Secondary objectives included overall response rate (ORR) and overall survival (OS). Median TTP was 3.8 months, when compared with 3.5 months for thrice daily. The ORR (11%) and median OS (12.8 months) with twice daily administration were similar to that of thrice daily administration (12% and 12.4 months). The incidence of grade 3/4 treatment-related diarrhoea was 30% on the twice daily and 21% on the thrice daily schedule. These results suggest that twice daily administration has similar efficacy and tolerability to thrice daily administration and is an acceptable alternative for patients who would benefit from UFT with LV therapy.