Phase I and pharmacokinetic study of irinotecan in combination with raltitrexed

PURPOSE. To determine the maximum tolerated dose (MTD) of raltitrexed when given with irinotecan and to evaluate the pharmacokinetics of these two agents when given in combination. METHODS. Patients with advanced solid tumors received irinotecan intravenously over 90 min on days 1 and 8 of each 21-day cycle, with raltitrexed given intravenously over 15 min after irinotecan either on day 1 (cohorts 1-7) or day 2 (cohorts 8-9). The 39 patients received irinotecan and raltitrexed in cohorts of three to six patients at the following dose levels (mg/m(2)): 100/1.0, 100/1.5, 100/2.0, 100/2.5, 100/3.0, 100/3.5, 125/3.0, 75/3.0, 100/3.0. Pharmacologic monitoring of irinotecan and raltitrexed was carried out during cycle 1. RESULTS. A total of 39 patients received irinotecan and raltitrexed in cohorts of three to six patients at nine dose levels. The MTD with dosing of irinotecan on days 1 and 8 and raltitrexed on day 1 was 100 mg/m(2) and 3.0 mg/m(2), respectively, every 21 days, with dose-limiting toxicities (DLTs) of fatigue, neutropenia and diarrhea. When raltitrexed was administered 24 h after irinotecan, these doses exceeded the MTD. No pharmacologic interactions were observed between these agents, and no correlations between pharmacokinetic parameters and toxicity were noted. Of 26 patients with colorectal cancer, 6 had objective partial responses (23%). Four of these patients had previously received a 5-FU-based regimen, two for metastatic disease. CONCLUSIONS. Irinotecan can be safely administered with raltitrexed on a day-1 and day-8 schedule at 100 mg/m(2) and 3.0 mg/m(2), respectively, every 21 days. When raltitrexed was given on day 2, these doses were not tolerated, necessitating a dose reduction of the irinotecan to 75 mg/m(2). This regimen possesses clinical activity in patients with colorectal cancer.     

Multicenter phase I study of irinotecan plus raltitrexed in patients with 5-fluorouracil-refractory advanced colorectal cancer

Irinotecan and raltitrexed are active against advanced colorectal cancer, act through different mechanisms, and have non-overlapping toxicity profiles. In vitro studies have shown a schedule-dependent synergism between both drugs. The aim of this multicenter study was to determine the maximum tolerated dose (MTD) of this combination. Patients with 5-fluorouracil-refractory, advanced colorectal cancer were eligible. Dose escalation consisted of irinotecan (250-350 mg/m(2) as a 60-min infusion) in combination with a fixed dose of raltitrexed (3 mg/m(2) as a 15-min infusion, 1 h after irinotecan). Courses were repeated every 21 days. Three to 6 patients were to be included at each dose level. Dose limiting (NCI-CTC grade 3-4) toxicities (DLT) were assessed during the first 2 cycles. Thirteen patients were recruited (4, 3 and 6 in levels I, II and III, respectively). Main toxicity was diarrhea and asthenia, whereas myelotoxicity was mild. At level III, 2/6 patients experienced DLT (grade 4 diarrhea and neutropenia). The MTD was not reached, but further dose escalation was not attempted. Among 12 patients with measurable disease, 2 partial responses were observed for an overall response rate of 17%. The combination of single-agent full doses of irinotecan (350 mg/m(2)) and raltitrexed (3 mg/m(2)) in a 3-weekly schedule is feasible, with mild toxicity and a promising clinical activity. Diarrhea is the DLT, but it is not more common or severe than that described with irinotecan alone.     

Phase I study of intraperitoneal irinotecan in patients with gastric adenocarcinoma with peritoneal seeding

Purpose

The objectives of this phase I study were to determine the maximum-tolerated dose (MTD), dose-limiting toxicities (DLTs), and preliminary efficacy of intraperitoneally administered irinotecan (CPT-11) in gastric cancer patients with peritoneal seeding.

Experimental design

Gastric adenocarcinoma patients with surgical biopsy proven peritoneal seeding were enrolled at the time of surgery. Prior to IP chemotherapy, patients underwent palliative gastrectomy and CAPD catheter insertion in which CPT-11 was administered on postoperative day 1. The IP CPT-11 was initiated at 50?mg/m², which was escalated to 100, 150, 200, 250, and 300?mg/m². IP CPT-11 chemotherapy was repeated every 3?weeks.

Results

Seventeen patients received a total of 56?cycles at five different CPT-11 dose levels. The DLTs were neutropenic fever, neutropenia, and diarrhea. At the dose level 2 (100?mg/m²), there were one DLTs in one of the first cohort of three patients, but no DLTs at the second cohort of this level. At the dose level 5 (250?mg/m²), two DLTs were detected in the first two patients; thus, the accrual was stopped resulting in the recommended dose of IP CPT-11 of 200?mg/m². Median progression-free survival was 8.6?months (95% CI, 5.9,11.2), and median overall survival was 15.6?months (95% CI, 8.4,22.8). Pharmacokinetic results of the study showed that the C _max of peritoneal SN-38 was achieved earlier than that of plasma SN-38.

Conclusions

Intraperitoneally administered CPT-11 was feasible and tolerable. Further, phase II study of IP CPT-11 in gastric cancer patients with peritoneal seeding is warranted.     

Phase I study of docetaxel and irinotecan in patients with advanced non-small-cell lung cancer

The role of non-platinum combination chemotherapy in the treatment of advanced non-small-cell lung cancer (NSCLC) has not yet been clarified. In this phase I study, the dose-limiting toxicity (DLT), the maximum tolerable dose (MTD) and the antitumor activity of a two-drug combination of docetaxel (DCT) and irinotecan (CPT) in patients with advanced NSCLC were evaluated. Previously untreated patients with NSCLC in stage IIIB with malignant pleural effusion or stage IV were eligible. Both drugs were administered by 1-h intravenous infusion on day 1, and repeated every 3 weeks. DCT was given before CPT administration. Five escalating dose levels of DCT/CPT (40/135, 50/135, 50/150, 60/150, and 60/165 mg/m2) were studied. Eighteen patients received 44 courses. The DLT was considered to be neutropenia, because grade 4 neutropenia lasting for 3 days or more was observed in three patients, which was accompanied with three episodes of febrile neutropenia. As a non-hematological toxicity, grade 3 diarrhea occurred in three patients. Since all the three patients treated at the fifth dose level (DCT at 60 mg/m2 and CPT at 165 mg/m2) experienced DLT (grade 4 neutropenia in two patients and grade 3 hepatic toxicity in one), this dose level was determined to be the MTD. The objective response rate was 33.3%, and the median survival time was 13.6 months. To confirm the effectiveness of this combination for advanced NSCLC which was suggested in the present study, a phase II study with the recommended doses (150 mg/m2 for CPT and 50-60 mg/m2 for DCT) is warranted.     

Phase I-II study of irinotecan in combination with mitomycin C in patients with advanced gastrointestinal cancer

This phase I-II study was conducted to determine the maximum tolerated dose and optimal schedule of a combination of irinotecan (CPT 11) and mitomycin C (MMC) in a population of previously treated patients with gastrointestinal malignancies. Four cohorts of patients were recruited with MMC given at 8 mg/m2 for the first 3 levels together with irinotecan at 300 mg/m2, 325 mg/m2, and 350 mg/m2; the fourth dose level was given with MMC at 10 mg/m2 and irinotecan at 325 mg/m2. All treatment was repeated at 21-day intervals. The dose-limiting toxicity was hematologic (thrombocytopenia at level 4), and the recommended doses for subsequent phase II studies are MMC 8 mg/m2 with irinotecan 325 mg/m2. Evidence of efficacy was seen at all dose levels examined and justifies further exploration of this combination in a less heavily pretreated patient population.     

A Phase I study of bortezomib plus irinotecan in patients with advanced solid tumors

BACKGROUND: The authors conducted a Phase I dose-finding trial to study the use of combined bortezomib plus irinotecan in patients with advanced solid tumors. METHODS: Patients who had received >/=1 prior chemotherapy regimen were eligible. Patients received bortezomib (1.0 mg/m(2), 1.3 mg/m(2), or 1.5 mg/m(2)) on Days 1, 4, 8, and 11 and received irinotecan (from 50 mg/m(2) to 125 mg/m(2)) on Days 1 and 8 of each 21-day cycle for a maximum of 8 cycles. Bortezomib followed irinotecan on coadministration days in Cycle 1 and Cycles 3 through 8 but preceded irinotecan in Cycle 2 to assess the effect of administration sequence on bortezomib pharmacodynamics. RESULTS: Fifty-one enrolled patients with malignancies, including colorectal cancer (n = 23 patients), lung cancer (n = 6 patients), gastroesophageal cancer (n = 6 patients), and pancreatic cancer (n = 3 patients), received >/=1 dose of study drug. Nausea, vomiting, and diarrhea were the principal dose-limiting toxicities and led to the maximum tolerated doses of 1.3 mg/m(2) bortezomib and 125 mg/m(2) irinotecan. The most common grade >/=3 bortezomib-related nonhematologic adverse events were fatigue (n = 5 episodes), diarrhea (n = 4 episodes), and nausea (n = 4 episodes). grade >/=3 bortezomib-related hematologic adverse events included neutropenia (n = 6 episodes) and thrombocytopenia (n = 4 episodes) and rarely were dose limiting. Of 34 evaluable patients, no objective responses according to the Response Evaluation Criteria in Solid Tumors were seen; 10 patients achieved stable disease. The degree of proteasome inhibition in whole blood indicated that the biologic activity of bortezomib was unaffected by irinotecan coadministration. CONCLUSIONS: The results of this Phase I study in patients with solid tumors indicated that bortezomib at a dose of 1.3 mg/m(2) on Days 1, 4, 8, and 11 plus irinotecan at a dose of 125 mg/m(2) on Days 1 and 8 every 21 days were the recommended Phase II doses.     

Irinotecan plus raltitrexed vs raltitrexed alone in patients with gemcitabine-pretreated advanced pancreatic adenocarcinoma

There is no established second-line treatment for advanced pancreatic cancer after gemcitabine failure. In view of the urgent need for such therapy, and since preclinical and phase I clinical data suggest an encouraging, potentially synergistic activity between raltitrexed and irinotecan, the present randomised phase II study was initiated. A total of 38 patients with metastatic pancreatic adenocarcinoma, who progressed while receiving or within 6 months after discontinuation of palliative first-line chemotherapy with gemcitabine, were enrolled in this study. They were randomised to 3-weekly courses of raltitrexed 3 mg x m(-2) on day 1 (arm A) or irinotecan 200 mg x m(-2) on day 1 plus raltitrexed 3 mg x m(-2) on day 2 (arm B). The primary study end point was objective response, secondary end points included progression-free survival (PFS) and overall survival (OS), as well as clinical benefit response in symptomatic patients (n=28). In the combination arm, the IRC-confirmed objective response rate was 16% (three out of 19 patients had a partial remission; 95% CI, 3-40%), which was clearly superior to that in the comparator/control arm with raltitrexed alone, in which no response was obtained. Therefore, the trial was already stopped at the first stage of accrual. Also, the secondary study end points, median PFS (2.5 vs 4.0 months), OS (4.3 vs 6.5 months), and clinical benefit response (8 vs 29%) were superior in the combination arm. The objective and subjective benefits of raltitrexed+irinotecan were not negated by severe, clinically relevant treatment-related toxicities: gastrointestinal symptoms (42 vs 68%), partial alopecia (0 vs 42%), and cholinergic syndrome (0 vs 21%) were more commonly noted in arm B; however, grade 3 adverse events occurred in only three patients in both treatment groups. Our data indicate that combined raltitrexed+irinotecan seems to be an effective salvage regimen in patients with gemcitabine-pretreated pancreatic cancer. The superior response activity, PFS and OS (when compared to raltitrexed), as well as its tolerability and ease of administration suggest that future trials with this combination are warranted.     

Phase I and pharmacokinetic study of docetaxel and irinotecan in patients with advanced solid tumors.

PURPOSE: We conducted a phase I and pharmacokinetic study of docetaxel in combination with irinotecan to determine the dose-limiting toxicity (DLT), the maximum-tolerated dose (MTD), and the dose at which at least 50% of the patients experienced a DLT during the first cycle, and to evaluate the safety and pharmacokinetic profiles in patients with advanced solid tumors. PATIENTS AND METHODS: Patients with only one prior chemotherapy treatment (without taxanes or topoisomerase I inhibitors) for advanced disease were included in the study. Docetaxel was administered as a 1-hour IV infusion after premedication with corticosteroids followed immediately by irinotecan as a 90-minute IV infusion, every 3 weeks. No hematologic growth factors were allowed. RESULTS: Forty patients were entered through the following seven dose levels (docetaxel/irinotecan): 40/140 mg/m(2), 50/175 mg/m(2), 60/210 mg/m(2), 60/250 mg/m(2), 60/275 mg/m(2), 60/300 mg/m(2), and 70/250 mg/m(2). Two hundred cycles were administered. Two MTDs were determined, 70/250 mg/m(2) and 60/300 mg/m(2); the DLTs were febrile neutropenia and diarrhea. Neutropenia was the main hematologic toxicity, with 85% of patients experiencing grade 4 neutropenia. Grade 3/4 nonhematologic toxicities in patients included late diarrhea (7.5%), asthenia (15.0%), febrile neutropenia (22.5%), infection (7.5%), and nausea (5.0%). Pharmacokinetics of both docetaxel and irinotecan were not modified with the administration schedule of this study. CONCLUSION: The recommended dose of docetaxel in combination with irinotecan is 60/275 mg/m(2), respectively. At this dose level, the safety profile is manageable. The activity of this combination should be evaluated in phase II studies in different tumor types.     

Phase I, dose-finding, and pharmacokinetic study of raltitrexed combined with oxaliplatin in patients with advanced cancer.

PURPOSE: To determine the maximum-tolerated dose (MTD) and the dose-limiting toxicities (DLTs) of the raltitrexed plus oxaliplatin combination regimen, to explore its safety and pharmacokinetics, and to assess its antitumor activity in patients with advanced solid tumors. PATIENTS AND METHODS: Forty-eight patients received the combination of raltitrexed plus oxaliplatin. Raltitrexed was administered as a 15-minute infusion followed by oxaliplatin as a 2-hour infusion 1 hour later, repeated every 3 weeks. Seven dose levels were explored, ranging from 2 to 3.75 mg/m(2) and from 85 to 130 mg/m(2) for raltitrexed and oxaliplatin, respectively. The pharmacokinetics of both raltitrexed and oxaliplatin was assessed at the last three dose levels. RESULTS: Forty-six patients were assessable for toxicity. Severe toxicities usually occurred from dose level V (raltitrexed 3 mg/m(2) and oxaliplatin 130 mg/m(2)). This combination was not myelosuppressive, eliciting only sporadic grades 3 and 4 neutropenia and/or thrombocytopenia without complications. There was no alopecia. DLTs were asthenia and nausea/vomiting, despite systematic antiemetic prophylaxis. Dose level VI (raltitrexed 3.5 mg/m(2) and oxaliplatin 130 mg/m(2)) was deemed to be the MTD. Eight confirmed partial responses were observed: six patients with malignant mesothelioma (both pretreated and nonpretreated), one with fluorouracil-refractory pancreatic carcinoma, and one with renal carcinoma. Evaluation of the pharmacokinetics of both drugs did not suggest any drug interaction. CONCLUSION: The combination of raltitrexed and oxaliplatin given as consecutive short infusions every 3 weeks seems to be an acceptable regimen that allows a dose-intensity as high as the sum of the recommended doses of each agent given alone. The dose recommended for further phase II studies is raltitrexed 3 mg/m(2) and oxaliplatin 130 mg/m(2) every 3 weeks. Promising antitumor activity has been observed in patients with malignant mesothelioma.     

Phase I study of concomitant chemoradiation with raltitrexed in locally advanced head and neck cancer

In patients with non-resectable head and neck cancer concomitant chemoradiotherapy is increasingly used, especially in cases of oropharyngeal and hypopharyngeal tumours. Most chemoradiotherapy regimes contain cisplatin as a single agent or in combination with fluorouracil. However, not all patients are fit enough for a cisplatin-containing regime or they refuse hospital admission. Raltitrexed is a specific thymidylate synthase inhibitor that has been studied as a radiosensitiser in rectal cancer. Raltitrexed can be administered easily in an outpatient setting and has few short-term effects. We studied raltitrexed at escalating doses combined with standard radiotherapy in advanced head and neck cancer patients. Seventeen patients with locally advanced head and neck cancers were enrolled in the study. Raltitrexed was administered at dose levels of 1.5, 2.0, 2.5 and 3.0 mg/m(2) intravenously (i.v), once every 3 weeks, for two doses. Radiotherapy consisted of 70 Gy given over 7 weeks in five fractions of 2 Gy per week. In general, treatment toxicity (DLT), complicated febrile neutropenia, was observed at 3.0 mg/m(2) in two of four patients. The dose of 2.5 mg/m(2) was extended thereafter with additional patients without major toxicity. Radiotherapy had to be interrupted in one patient. Five patients had a clinical complete response(CR) and eleven a partial response (PR) six weeks after the last fraction of radiotherapy. Twelve out of 17 patients remained free of locoregional recurrence after a median follow-up of 24(+) months (range 3-60+ months). Raltitrexed, at a dose of 2.5 mg/m(2) given twice 3 weeks apart, can be administered in combination with 70 Gy of radiotherapy in locally advanced head and neck cancer patients with a manageable tolerability profile. The clinical results and convenience of the schedule make raltitrexed an attractive drug to explore further in patients considered unfit for cisplatin-containing chemoradiation regimens.     

Phase I study of vinorelbine and irinotecan in previously untreated patients with advanced non-small cell lung cancer

Introduction Vinorelbine alone and irinotecan alone have been shown to have efficacy against non-small cell lung cancer (NSCLC); each drug has different mechanisms of action. A phase I study using a combination of vinorelbine and irinotecan as first-line treatment for advanced NSCLC was done to determine the maximum tolerated dose (MTD) and the dose-limiting toxicity (DLT). Methods Previously untreated patients (≤75 years old) with Stage IIIB or IV NSCLC were enrolled. Based on a 4-week cycle, vinorelbine was given on days 1 and 8, and irinotecan was given on days 1, 8, and 15 intravenously. To prevent an injection site reaction to vinorelbine, the site was treated with topical clobetasol ointment, and the patients were given intravenous dexamethasone prior to vinorelbine treatment. DLT was defined as grade 4 neutropenia lasting ≥4 days or febrile neutropenia, grade 4 thrombocytopenia, ≥grade 3 non-hematological toxicities, or the need to cancel drug administration on both days 8 and 15. Results A total of 23 patients were enrolled. DLT was observed in 1 of 6 patients at level 3 (20 mg/m² vinorelbine, 50 mg/m² irinotecan), in 2 of 3 at level 4 (25 mg/m², 50 mg/m²), and in 2 of 5 at modified level 4 (20, 60 mg/m²). Level 4 and modified level 4 were considered to be the MTD; dose level 3 was therefore recommended. DLTs included liver dysfunction, pneumonitis, colitis, and arrhythmia. Injection site reactions were mild. Hematological and non-hematological toxicities were mild and easily controlled. Conclusion Use of 20 mg/m² vinorelbine on days 1 and 8 followed by 50 mg/m² irinotecan on days 1, 8, and 15 every 4 weeks warrants a phase II study.     

Phase I study of irinotecan and gemcitabine in previously untreated patients with advanced non-small cell lung cancer

BACKGROUND: Irinotecan and gemcitabine are effective against non-small cell lung cancer. We conducted a phase I study of the combined use of irinotecan and gemcitabine in previously untreated patients with advanced non-small cell lung cancer to determine dose-limiting toxicities and maximum tolerated dose. METHODS: Patients were treated with irinotecan followed by gemcitabine on days 1 and 8 every 3 weeks. Gemcitabine dose was fixed at 1000 mg/m2, and irinotecan dose was increased from 60 mg/m2. RESULTS: A total of 16 patients was enrolled. Maximum tolerated dose of irinotecan was determined up to level 3 (irinotecan 100 mg/m2). In Japan, the maximum approved weekly dose of irinotecan is 100 mg/m2, so this was the dose that was used. Only very mild hematological and non-hematological toxicities were noted. CONCLUSION: Use of 100 mg/m2 irinotecan followed by 1000 mg/m2 gemcitabine on days 1 and 8 every 3 weeks warrants a phase II study.     

Phase I and pharmacokinetic study of paclitaxel and irinotecan for patients with advanced non-small cell lung cancer

We conducted a phase I study of paclitaxel and irinotecan (CPT-11) in advanced non-small cell lung cancer (NSCLC). This study aimed to determine the maximum tolerated doses (MTD). The pharmacokinetics of CPT-11 and its major active metabolite, SN-38, were also analysed. Patients received paclitaxel (day 1) followed by CPT-11 (days 1, 8 and 15), in a 4-week cycle, and paclitaxel and CPT-11 were escalated from 120 and 40 mg/m(2), respectively. 28 patients were enrolled, who were evaluated for toxicity. 2 of 6 patients at 210 mg/m(2) paclitaxel and 50 mg/m(2) CPT-11, and 2 of 4 at 180 and 60 mg/m(2) developed dose-limiting toxicity (DLT) (neutropenia, fever, neurotoxicity and diarrhoea). The area under the plasma concentration-time curve (AUC) of CPT-11 on day 1 was significantly higher than that on days 8 or 15 at each dose level (P=0.002). The AUC of SN-38 on day 1 was significantly increased using paclitaxel doses >or=150 mg/m(2). A preceding paclitaxel administration changed the pharmacokinetics of CPT-11 and SN-38. However, the toxicity was tolerable. Paclitaxel 180 mg/m(2) and CPT-11 50 mg/m(2) were the recommended doses for further phase II study of this combination.     

Phase I trial of UFT/leucovorin and irinotecan in patients with advanced cancer

UFT (BMS-200604, Uftoral) is an oral fluoropyrimidine that combines uracil and the 5-fluorouracil (5-FU) prodrug, ftorafur, in a 4:1 molar ratio with single-agent activity in breast and gastrointestinal cancers. In vitro studies have shown that irinotecan downregulates thymidylate synthase (TS) expression in tumour cells, leading to synergy between irinotecan and 5-FU that is maximal when irinotecan is given 24 h prior to 5-FU. Given this observed synergy and the confirmatory clinical activity of combination therapy with 5-FU, leucovorin (LV) and irinotecan, we performed a phase I trial to determine the maximum tolerated doses (MTD) of UFT, LV, and irinotecan. Treatment consisted of irinotecan administered as a 90-min intravenous (i.v.) infusion on day 1 followed by twice daily oral UFT/LV on days 2-15, repeated every 21 days. Initial doses were irinotecan 200 mg/m(2) and UFT 200 mg/m(2)/day, with LV dose fixed at 60 mg/day. 31 patients received a total of 130 cycles of UFT/LV and irinotecan. 3 of 9 patients experienced grade 3/4 diarrhoea at the highest dose level of irinotecan 310 mg/m(2) and UFT 300 mg/m(2)/day. Other toxicities included neutropenia, anaemia, alopecia, nausea/vomiting and fatigue. Further dose escalation was not pursued since this level of toxicity was appropriate for future phase II study. One patient with colorectal cancer experienced a partial response and 9 patients with non-small cell lung, colorectal and gastro-oesophageal junction carcinomas had disease stabilisation lasting 4-26 (median 6) cycles. Methylenetetrahydrofolate reductase (MTHFR) C677T genotype was analysed in peripheral mononuclear cells (PMNs) obtained from 24 patients. 2 patients had the homozygous TT polymorphism and 1 of them had grade 3 diarrhoea at the first dose level. Irinotecan on day 1 followed by a 14-day course of oral UFT/LV beginning on day 2 is well tolerated, and suitable for testing in several tumour types. Doses recommended for further study on this schedule are irinotecan 310 mg/m(2) and UFT 300 mg/m(2)/day, with LV 60 mg/day.     

Phase I clinical and pharmacogenetic trial of irinotecan and raltitrexed administered every 21 days to patients with cancer.

PURPOSE: Irinotecan and raltitrexed display schedule-dependent synergy in vitro, which supports the clinical investigation of the combination. Functional polymorphisms of the methylenetetrahydrofolate reductase (MTHFR) gene result in intracellular redistribution of folate derivatives, which may affect raltitrexed-associated cytotoxicity. PATIENTS AND METHODS: Patients with a range of solid cancers and good performance status received irinotecan as a 90-minute infusion on day 1 and raltitrexed as a 15-minute infusion on day 2, repeated every 21 days. Samples were collected for MTHFR C677T genotyping and fasting plasma homocysteine during the first cycle. RESULTS: Thirty-nine assessable patients received 127 cycles of therapy. Irinotecan doses ranged from 100 to 350 mg/m(2), and raltitrexed, 1.0 to 4.0 mg/m(2). Raltitrexed doses of more than 3.0 mg/m(2) were not tolerated and were associated with dose-limiting asthenia, diarrhea, and AST/ALT elevation. Irinotecan/raltitrexed doses of 350/3.0 mg/m(2) were well-tolerated; principal toxicities included neutropenia, diarrhea, and fatigue. Two partial responses were observed in patients with pretreated gastroesophageal cancers. Homozygotes with the MTHFR 677 TT polymorphism incurred significantly less raltitrexed-associated toxicity than those with either wild-type or heterozygous genotypes (P = .05). No significant differences were noted in plasma homocysteine values between the genotypic subtypes, and plasma homocysteine levels did not predict the risk of toxicity. CONCLUSION: Irinotecan and raltitrexed doses of 350 and 3.0 mg/m(2) are recommended for further study on a day 1, 2 schedule every 21 days. Efficacy results suggest that trials in upper and lower gastrointestinal malignancies are warranted. MTHFR C677T genotypes may be predictive of clinical raltitrexed toxicity.     

Phase I study of weekly CPT-11 (irinotecan)/docetaxel in patients with advanced solid tumors

Based on the synergistic cytotoxicity demonstrated in vitro by topoisomerase I inhibitors followed by docetaxel and the feasibility of giving both drugs on a weekly schedule avoiding overlapping toxicities, we designed a phase I trial of weekly CPT-11 (irinotecan)/docetaxel to determine the dose-limiting toxicities (DLT) and the maximum-tolerated dose (MTD) of this combination. Eighteen patients with advanced solid tumors treated with at least one prior chemotherapy regimen were included in this trial. CPT-11 was administered as a 90-min (intravenous) IV infusion followed immediately by docetaxel as a 30-min IV infusion. Both drugs were given on days 1, 8 and 15 in 4-week cycles. Four escalating dose levels of CPT-11/docetaxel (level I: 60/20 mg/m(2), level II: 60/25 mg/m(2), level III: 70/25 mg/m(2), and level IV: 70/30 mg/m(2)) were studied. Forty-seven cycles were administered (range, 1-5 courses) with a median number of 2.6 cycles per patient. Grade 4 leukopenia was the DLT reached at dose-level IV (CPT-11/docetaxel 70/30 mg/m(2)). Four patients had grade 3 anemia at dose levels III (two patients) and IV (two patients), while grade 3/4 thrombocytopenia was not seen. Grade 3/4 non-hematologic toxicities included grade 3 diarrhea in two patients (dose levels II and IV), grade 3 asthenia in one patient (dose level II) and grade 3 stomatitis in one patient (dose level I). The recommended dose of this weekly schedule is CPT-11 70 mg/m(2) and docetaxel 25 mg/m(2). DLT of this regimen is leukopenia, although toxicity is manageable at the recommended dose level. The activity of this regimen is being evaluated in a phase II study in previously treated patients with advanced non-small cell lung cancer.     

A phase I and II study of 2-weekly irinotecan with capecitabine in advanced gastroesophageal adenocarcinoma

We investigated 2-weekly intravenous irinotecan combined with oral capecitabine in patients with advanced gastroesophageal adenocarcinoma. In phase I, doses were escalated in chemotherapy naïve or pretreated patients to establish maximum tolerated doses (MTD). In phase II, patients were treated at MTD as first-line therapy with the primary end point of RECIST response. Dose levels in phase I were as follows: Level 1: irinotecan 150 mg m⁻² on day 1; capecitabine 850 mg m⁻² 12-hourly on days 1–9. Level 2: as level 1 but capecitabine 1000 mg m⁻². Level 3: as level 2 but irinotecan 180 mg m⁻². Level 4: as level 3 but capecitabine 1250 mg m⁻². In phase I, 21 patients were entered. Maximum tolerated dose was level 3. Dose-limiting toxicities were lethargy, diarrhoea, vomiting and mucositis. In phase II, 31 patients were entered at level 3. During the first six cycles, 13 of these patients underwent dose reduction and three patients stopped treatment for toxicity. A further six patients stopped for progressive disease. The commonest grade 3–4 toxicities were lethargy (20%), diarrhoea (17%), nausea (10%) and anorexia (10%). There were no treatment-related deaths. The response rate was 32% (95% CI 16–52%). Median overall survival was 10 months. This regimen is active in gastroesophageal adenocarcinoma. However, using the MTD defined in phase I, fewer than 50% patients tolerated six cycles without modification in phase II; therefore, modification of these doses is recommended for further study.     

Phase I and pharmacokinetic study of the farnesyltransferase inhibitor R115777 in combination with irinotecan in patients with advanced cancer

Purpose R115777 is a selective, nonpeptidomimetic inhibitor of farnesyltransferase (FTase), an enzyme responsible for the post-translational modification of several proteins, including Ras. Given the high frequency of K-Ras mutations in malignancies commonly treated with irinotecan, the broad preclinical antiproliferative activity of R115777 and its largely non-overlapping toxicity profile with irinotecan, this phase I study of the combination of R115777 and irinotecan in patients with advanced cancer was undertaken.Patients and methods Enrolled onto the study were 14 patients (eight male, six female; median age 63 years, range 48–72 years). Five patients had an ECOG performance status (PS) of 0, eight patients PS 1, and one patient PS 2. The patients were treated with R115777 orally twice daily for 28 days and irinotecan 100 mg/m² as an intravenous infusion on days 1, 8, 15, and 22 of each 42-day cycle. Seven patients received R115777 100 mg twice daily and seven received R115777 200 mg twice daily.Results Dose-limiting toxicity (DLT) was experienced by one of seven patients treated with R115777 100 mg (grade 3 fatigue), and two of seven patients treated with R115777 200 mg (grade 3 diarrhea, grade 4 neutropenia lasting >5 days). The maximum tolerated dose (MTD) was R115777 100 mg twice daily and irinotecan 100 mg/m² weekly. Non-DLTs were primarily rash, fatigue, diarrhea, and neutropenia. R115777 demonstrated linear pharmacokinetics without interaction with irinotecan and achieved serum levels required for antitumor activity in vitro.Conclusions Serum levels of R115777 exceeded those necessary for FTase inhibition in vitro without evidence of interaction with irinotecan. However, the MTD of R115777 in this study was lower than that obtained with an alternate schedule. Thus, further development of this schedule is not recommended.This work was supported by a grant from Johnson and Johnson Pharmaceutical Research and Development and NCI K12 CA01728.