A Phase I trial of protracted oral fixed-dose temozolomide.

BACKGROUND: The current Phase I trial was conducted to determine the dose-limiting toxicity (DLT), maximum tolerated dose, and recommended Phase II dose of oral fixed-dose temozolomide when administered for 5 of every 7 days on a continuous basis. METHODS: Patients received a fixed dose of temozolomide daily for 5 of every 7 days continuously. Four weeks of treatment were considered 1 treatment cycle. Patients were accrued at 7 different dose levels ranging from 100 mg/day to 360 mg/day. RESULTS: Forty-six patients received 111 cycles of therapy. DLT consisted of myelosuppression, particularly thrombocytopenia. The primary nonhematologic toxicities were nausea and emesis, which were easily controlled with antiemetics. CONCLUSIONS: Protracted administration of temozolomide at a fixed dose of 300 mg/day for 5 of every 7 days continuously was well tolerated and allowed greater dose intensity compared with various other schedules. This regimen could potentially increase antitumor activity as protracted temozolomide schedules inhibit DNA repair by depletion of the repair protein O6-methylguanine-DNA methyltransferase.

A phase I/II study of exisulind in combination with docetaxel/carboplatin in patients with metastatic non-small-cell lung cancer.

Exisulind is a sulfone derivative of sulindac that induces apoptosis and demonstrates synergy with docetaxel in lung cancer models. This study evaluated the safety, efficacy, and pharmacokinetic interactions of exisulind and docetaxel/carboplatin in patients with metastatic non-small-cell lung cancer (NSCLC). Fifty-seven patients received 218 cycles of docetaxel (75 mg/m2) and carboplatin (area under the curve, 5.0) in combination with exisulind (125-250 mg orally twice daily). Two complete responses and 9 partial responses were observed among the 47 patients assessable for response (overall response rate, 23%). The median duration of response was 5.9 months and median survival was 9.4 months. The 1- and 2-year survival rates are 35% and 14%, respectively. The hematologic toxicities were consistent with those previously reported with docetaxel/carboplatin. The most common nonhematologic toxicities were mild to moderate fatigue, anorexia, nausea, and vomiting. The addition of exisulind to the chemotherapy regimen did not interfere with the metabolism or elimination of docetaxel and vice versa, and docetaxel did not interfere with the pharmacokinetic parameters of exisulind. This trial did not allow direct comparison of patients receiving docetaxel/carboplatin with and without exisulind, but when compared with historical data of docetaxel/carboplatin alone, the addition of exisulind does not appear to enhance antitumor activity, duration of response, or survival. Although preclinical data demonstrate increased apoptosis and prolonged survival for the combination of exisulind and docetaxel, multiple clinical trials do not support further clinical development of this combination regimen in patients with advanced NSCLC.

Phase I. Trial of irinotecan plus carboplatin in two dose schedules.

A phase I study of carboplatin (Paraplatin) administered in two different dosing schedules (single dose every 4 weeks and weekly dosing) in combination with weekly irinotecan (CPT-11, Camptosar) was conducted in patients with relapsed or refractory advanced malignancies. Fifty-three patients with a variety of tumor types were randomly enrolled on the two different treatment regimens and have received a total of 163 cycles of treatment to date. Twenty-six patients received weekly irinotecan in combination with a single fixed dose of every-4-week carboplatin (arm 1). Initially, patients received irinotecan on days 1, 8, and 15, in combination with fixed-dose carboplatin at an area under the concentration-time curve (AUC) of 5.5 (Calvert formula) on day 1 every 28 days. Due to dose-limiting toxicities encountered at the first two dose levels, the protocol was amended to decrease the fixed dose of carboplatin to an AUC of 4.0 every 4 weeks. Dose-limiting toxicity was again encountered, so the day-15 dose of irinotecan was eliminated from the dosing regimen. The recommended phase II dose for heavily pretreated patients is irinotecan at 60 mg/m2 on days 1 and 8 in combination with carboplatin at AUC 4.0 on day 1 with cycles repeated every 28 days. Twenty-seven patients were treated with weekly irinotecan in combination with fixed-dose weekly carboplatin (arm 2). The initial dosing regimen consisted of irinotecan in combination with fixed-dose carboplatin at an AUC of 1.8 on days 1, 8, and 15, with treatment cycles repeated every 28 days. Due to the development of dose-limiting toxicities at the first two dose levels, the dosing regimen was subsequently amended to weekly irinotecan in combination with fixed-dose carboplatin at AUC 2.0 on days 1 and 8 only, and the dosing interval was shortened to every 21 days. With this amended regimen, the recommended phase II doses are irinotecan at 90 mg/m2 in combination with carboplatin at AUC 2.0 on days 1 and 8, with treatment cycles repeated every 21 days.

Phase I. Trial of irinotecan and temozolomide in patients with solid tumors.

This phase I study was conducted to determine the dose-limiting toxicity, maximum tolerated doses, and recommended phase II doses of the combination of irinotecan (CPT-11, Camptosar) and temozolomide (Temodar). Patients have received irinotecan and temozolomide on one of three different dosing schedules: (1) oral temozolomide on days 1-14 plus a single i.v. dose of irinotecan on day 8 every 28 days (arm 1); (2) weekly i.v. irinotecan on days 1, 8, 15, and 22 plus oral temozolomide on days 1-7 and 15-21 every 42 days (arm 2); and (3) every-other-week i.v. irinotecan on days 1 and 15 plus oral temozolomide on days 1-7 and 15-21 every 28 days (arm 3). A total of 49 patients have received 112+ cycles of therapy on all three dosing schedules to date. Dose-limiting toxicity consisting of diarrhea, neutropenia, and thrombocytopenia was encountered at a temozolomide dose of 125 mg/m2/d and an irinotecan dose of 250 mg/m2 on treatment arm 1. As a result, the protocol has been amended to explore lower doses of temozolomide in combination with higher doses of irinotecan, and patient accrual is currently continuing. Dose-limiting grade 3 diarrhea, nausea, and vomiting were reported in 7/12 patients enrolled on the two dose levels explored on treatment arm 2, so this dosing regimen was considered intolerable. Patient accrual currently continues at dose level 1 of treatment arm 3, so it is too early to determine dose-limiting toxicities and recommended phase II doses for this treatment schedule. Two partial responses have been reported to date in patients with glioblastoma and head and neck cancer, respectively. One evaluable response has also been observed in a patient with metastatic colorectal cancer. Irinotecan weekly x 4 plus temozolomide on days 1-7 and 15-21 is intolerable due to the development of dose-limiting gastrointestinal toxicities. The recommended phase II doses of irinotecan and temozolomide on treatment arms 1 and 3 remain to be determined as patient accrual is currently ongoing.

A phase I trial of weekly paclitaxel plus prolonged oral eniluracil/5-fluorouracil in patients with refractory malignancies.

PURPOSE: This phase I study was conducted to determine the dose-limiting toxicity (DLT), maximum-tolerated doses, and recommended phase II doses of the combination of weekly intravenous paclitaxel and oral eniluracil/5-fluorouracil (5-FU). PATIENTS AND METHODS: Patients received paclitaxel i.v. over 1 hour weekly for four consecutive weeks of each cycle. Oral eniluracil/5-FU was administered orally twice daily for 28 consecutive days starting on day 1 of each cycle. Cycles were repeated every 35 days. Patients were accrued at six different dosing combinations. Weekly paclitaxel doses ranged from 60 mg/m(2) to 80 mg/m(2), and oral eniluracil/5-FU doses ranged from 8.0/0.8 mg/m(2) to 11.5/1.15 mg/m(2) twice daily. RESULTS: Thirty-seven patients received 126 cycles of therapy. Myelosuppression was minimal at all dose levels, with no grade 4 neutropenia or thrombocytopenia reported. DLT was reported in three out of six patients enrolled at the highest dose level and consisted of grade 3 diarrhea (two patients) and grade 3 mucositis (one patient). No DLTs were reported in patients enrolled at lower dose levels. One complete response and three partial responses were reported in patients with taxane-resistant metastatic breast cancer. CONCLUSION: The combination of paclitaxel and eniluracil/5-FU was generally well tolerated. The recommended doses for further phase II testing are paclitaxel 80 mg/m(2) i.v. weekly for 4 weeks plus eniluracil/ 5-FU 10.0/1.0 mg/m(2) orally twice daily on days 1-28 with cycles repeated every 35 days.