Modulation of 5-fluorouracil with methotrexate and low-dose N-(phosphonacetyl)-L-aspartate in patients with advanced colorectal cancer. Results of a phase II study

Methotrexate (MTX) and N-phosphonacetyl-L-aspartate acid (PALA) have been shown to modulate the cytotoxic effects of 5-fluorouracil (5-FU). A phase II study was initiated to evaluate the feasibility, toxicity and efficacy of PALA/MTX and 5-FU in patients with metastatic colorectal cancer. 26 patients received PALA 250 mg/m2 as an intravenous 15-min infusion plus MTX 200 mg/m2 as a 30-min intravenous (i.v.) infusion on day 1 and 5-FU 600 mg/m2 as i.v. push on day 2. Cycles were repeated every 14 days and the 5-FU dose was escalated in the individual patient in steps of 100 mg/m2 for the third, fifth and seventh cycle in the absence of toxicity. 7 patients had received prior 5-FU-based chemotherapy while 19 patients were chemotherapy naive. Objective responses occurred in 23% of patients (1 CR, 5 PR of which 2 were pretreated), no change in 13 patients (50%) and tumour progression (6 patients) or toxic death (one patient) in 27%. Responses lasted for a median of 7 months (range 6-9), the median time to progression was 4 months and median survival 13 months. Toxicity was mainly gastrointestinal with diarrhoea and mucositis, and severe or life threatening in only 3 patients. In 3 patients an increase in serum glucose levels occurred while being treated with PALA/MTX and 5-FU. 2 patients with insulin-dependent diabetes had a 33% increase in insulin requirement and 1 patient with dietary-controlled diabetes died due to a ketoacidotic coma. PALA/MTX/5-FU in this dose and schedule is active in patients with colorectal cancer. Hyperglycaemia may be a potential side-effect of PALA-containing regimens especially in patients with diabetes. Careful monitoring of serum glucose levels in these patients is indicated.     

Treatment of advanced adenocarcinomas of the exocrine pancreas and the gallbladder with 5-fluorouracil, high dose levofolinic acid and oral hydroxyurea on a weekly schedule. Results of a multicenter study of the Southern Italy Oncology Group (G.O.I.M.)

BACKGROUND: To date there is no established chemotherapeutic treatment for patients with unresectable locally advanced and/or metastatic carcinomas of the exocrine pancreas or the gallbladder. A multicenter Phase II trial has been performed by the Southern Italy Oncology Group with the aim of evaluating the clinical effectiveness and tolerability of weekly 5-fluorouracil (5-FU) in modulation with intravenous (i.v.) high dose levofolinic acid and oral hydroxyurea. METHODS: A total of 70 patients fulfilling the standard eligibility for a Phase II study were enrolled in the trial. Forty patients had advanced pancreatic adenocarcinoma and 30 had advanced gallbladder carcinoma. The treatment schedule was: levofolinic acid, 100 mg/m2, in 500 mL of normal saline over 2-hour infusion followed by 5-FU, 600 mg/m2 i.v. bolus, and oral hydroxyurea, 1000 mg/m2, for 1 day every week for 6 consecutive weeks followed by 15 days of rest. RESULTS: Among the 40 patients with pancreatic adenocarcinoma, 5 (12.5%; 95% confidence level [CL], 8.5-16.5%) showed a partial response with a median duration of 5.6+ months, and 13 had stable disease. Twenty-two patients progressed. Median survival was 5.8 months. Among patients with advanced gallbladder carcinoma, 9 of 30 had a partial response (30%; 95% CL, 26-34%) with a median duration of 6.5 months, and 8 (27%) had stabilization of disease. Thirteen patients showed progressive disease. Median overall survival was 8 months. Toxicity was mild, with Grade 1 to 2 leukopenia and gastrointestinal toxicity the most frequent side effects. No chemotherapy-related deaths were observed. CONCLUSIONS: 5-FU in modulation with i.v. levofolinic acid and oral hydroxyurea on a weekly schedule is well tolerated by the vast majority of patients with locally advanced and/or metastatic carcinoma of the pancreas or the gallbladder. Although response rate and overall survival for patients with pancreatic adenocarcinoma are far from acceptable, the 30% overall response rate achieved in patients with advanced gallbladder carcinoma suggests that 5-FU in modulation with levofolinic acid and hydroxyurea is active in this neoplasm. The combination of modulated 5-FU with other antineoplastic drugs seems worthy of clinical testing in further controlled trials.     

A new complication of chemotherapy administered via permanent indwelling central venous catheter

BACKGROUND: The use of permanent intravenous access devices for chemotherapy administration has become a common practice in clinical oncology. Therefore, awareness of potential complications is important. The authors previously reported the use of high dose 5-fluorouracil (5-FU) (2600 mg/m2) and leucovorin (500 mg/m2) as a weekly 24-hour infusion for patients with colorectal carcinoma. In this report, a new complication of permanent indwelling catheters with high dose 5-fluorouracil (2600 mg/m2) and leucovorin (500 mg/m2) as a weekly 24-hour infusion for colorectal carcinoma is described. METHODS: Twenty-two patients in the previous Phase II trial on weekly high dose 5-FU and leucovorin were included in this study. All patients had either a single-lumen Port-o-cath (Pharmacia Deltec, St. Paul, MN) or Hickman catheter (Travenol Laboratories, Deerfield, IL). Occluded catheters were explanted, and the material found in their lumen was analyzed using infrared spectroscopy. RESULTS: Eleven of 22 patients had catheter blockage, and calcium carbonate formation (Calcite 100%) was identified within these catheters. CONCLUSION: Calcite formation causing catheter occlusion is a new and important complication resulting from using intravenous access devices for chemotherapy administration. Oncologists should be alerted to this phenomenon when high dose 5-FU and leucovorin are administered for 24 hours by continuous infusion using a single-port port-o-cath.     

Long-term weekly treatment of colorectal metastatic cancer with fluorouracil and leucovorin: results of a multicentric prospective trial of fluorouracil dosage optimization by pharmacokinetic monitoring in 152 patients

PURPOSE: A relationship between fluorouracil (5-FU) dose and response has been previously shown in advanced colorectal cancer. In a previous study with 5-FU stepwise dose escalation in a weekly regimen, and pharmacokinetic monitoring, we defined a therapeutic range for 5-FU plasma levels: 2,000 to 3,000 microg/L (area under the concentration-time curve at 0 to 8 hours [AUC0-8], 16 to 24 mg x h/L). The current study investigated 5-FU therapeutic intensification with individual dose adjustment in a multicentric phase II prospective trial. PATIENTS AND METHODS: Weekly high-dose 5-FU was administered by 8-hour infusion with 400 mg/m2 leucovorin. The initial dose of 5-FU (1,300 mg/m2) was adapted weekly according to 5-FU plasma levels, to reach the therapeutic range previously determined. RESULTS: A total of 152 patients entered the study from December 1991 to December 1994: 117 patients with measurable metastatic disease and 35 with assessable disease. Toxicity was mainly diarrhea (39%, with 5% grade 3) and hand-foot syndrome (30%, with 2% grade 3). Among 117 patients with measurable disease, 18 had a complete response (CR), 48 a partial response (PR), 35 a minor response (MR) and stable disease (SD), and 16 progressive disease (PD). Median overall survival time was 19 months. The 5-FU therapeutic plasma range was rapidly reached with a variable 5-FU dose in the patient population: mean, 1,803 +/- 386 mg/m2/wk (range, 950 to 3,396). Thirteen patients were immediately in the toxic zone, whereas 51 required a > or = 50% dose increase. CONCLUSION: Individual 5-FU dose adjustment with pharmacokinetic monitoring provided a high survival rate and percentage of responses, with good tolerance.     

5-fluorouracil and low-dose leucovorin as surgical adjuvant therapy from viewpoint of long-term outcome

Biochemical modulation of 5-FU by leucovorin (LV) has been demonstrated to increase the therapeutic effect compared to single agent 5-FU in the treatment of patients (pts) with advanced colorectal cancer. The purpose of this study was to determine the effectiveness of the 5-FU + LV combination as adjuvant therapy following surgery in pts with Dukes' B, C colon cancer. Pts were entered in a stratified clinical trial comparing two different combination chemotherapeutic regimens to single agent 5-FU, given orally as a control. This report summarized the result of treatment in 61 pts who were 5-FU oral alone and 32 pts who were 5-FU (375 mg/m2) and low-dose LV (20 mg/m2) intravenously for 5 days with 5-FU oral intake. 5-FU with LV regimen was associated with an improved survival compared with the single agent 5-FU oral intake (p < 0.05). 5-FU with LV regimen resulted in less recurrence in liver and lung compared with single-agent 5-FU oral intake.     

Risk factors for thrombotic events in giant cell arteritis and polymyalgia rheumatica

BACKGROUND: FOLFOX2, a bimonthly regimen of high-dose leucovorin (LV), 48-hour continuous infusion of 5-fluorouracil (5-FU) (LV-5-FU) and oxaliplatin (100 mg/m2) produced a high response rate (46%; 95% confidence interval (95% CI): 31%-60%) in 5-FU pre-treated patients with metastatic colorectal cancer. In this phase II study, pre-treated patients were given a lower dose of oxaliplatin to reduce the toxic effects of the regimen. PATIENTS AND METHODS: Thirty patients with advanced colorectal adenocarcinoma and progression while receiving bimonthly LV-5-FU (LV: 500 mg/m2, 5-FU: 1.5-2 g/m2/22 hours, days 1-2, every two weeks), were given the same LV-5-FU schedule with the addition of oxaliplatin (85 mg/m2) every two weeks (FOLFOX3). RESULTS: The main toxic effects were peripheral neuropathy (90%) with four severe sensitive neuropathies (WHO grade 2: 13%). The response rate was 20% (95% CI: 8%-39%). Median progression-free survival was 26 weeks, median survival was 57 weeks from the start of FOLFOX3 and median duration of the response was 37 weeks. CONCLUSIONS: Results obtained with FOLFOX3 confirmed the synergy between oxaliplatin and 5-FU in 5-FU-resistant metastatic colorectal cancer. However, the response rate seems to be lower than that obtained with FOLFOX2. Further studies to determine the best oxaliplatin dose intensity are in progress.     

Method of preventing hepatic artery occlusion during continuous intrahepatic arterial infusion chemotherapy of 5-FU

A randomized clinical trial of combined use of steroids, which have a vascular endothelium-protecting action, was performed to develop a method to prevent hepatic artery occlusion during continuous intrahepatic arterial infusion chemotherapy with 5-FU. The steroid used was dexamethasone palmitate (Limethason), which has a high rate of uptake by endothelial cells. The 24 patients with advanced colorectal cancer were divided into 2 groups randomly and both were treated with 5-FU 250 mg/day by continuous hepatic arterial infusion for three weeks. The weekly dose was 5-FU 7 V (1,750 mg) adjusted to 50 ml with physiological saline in Group A and 5-FU 7 V (1,750 mg) adjusted to 50 ml with Limethason 1 A (4.0 mg of dexamethasone palmitate) in Group B. The reservoir was replaced every week. No changes in the mixture (appearance, pH, granule diameter, dexamethasone palmitate content) were observed up to one week. Hepatic arterial stenosis was observed in 8 cases in Group A (67%), but was not observed in any of the cases in Group B. The above results indicated that Limethason has a preventive effect against hepatic artery occlusion.     

Biomodulation of Fluorouracil in colorectal cancer

5-Fluorouracil (5-FU) remains the agent of choice for the treatment of colorectal cancer. Research has focused on the biomodulation of 5-FU in order to attempt to improve the cytotoxity and therapeutic effectiveness of this drug in the treatment of advanced colorectal cancer. Modulation of 5-FU by methotrexate (MTX), trimetrexate (TMTX), interferon-alpha (IFN-alpha), leucovorin (LV), or N-(phosphonacetyl)-L-asparte acid (PALA) has produced higher response rates than those observed with 5-FU alone. Methotrexate may improve the durability of response to or survival with 5-FU, but with inferior results compared with those in trials of 5-FU and leucovorin. Trimetrexate produces a number of responses, and further phase III trials are in progress to confirm the results of promising phase II trials with this drug. IFN-alpha has shown therapeutic efficiency when combined with 5-FU alone or with 5-FU and leucovorin, but latest studies with these combinations have shown increased toxicity. Initial single-institution phase I trials with 5-FU and PALA reported promising responses, but the latter responses with PALA were not substantiated in randomized multicenter trials. Leucovorin enhances the cytotoxic activity of 5-FU in vitro and in vivo, and several clinical trials have shown improved response rates and possible trends in improved survival when such therapy is compared with the use of 5-FU as a single-agent. More recent randomized trials have focused their attention on determining the optimal dose and schedule with this combination for producing a better clinical response with minimal toxicity. Schedules using infusional 5-FU appear to be the most active regimens when 5-FU is used as a single agent, as demonstrated by recent randomized trials. The Southwest Oncology Group (SWOG) and the Eastern Cooperative Oncology Group (ECOG) have performed separate randomized trials and have shown that the optimal regimens employ infusional 5-FU as a single agent, and that these are the least toxic regimens, perhaps more effective, and associated with a better quality of life. Future studies will focus on infusional regimens involving either short-term, high-dose protracted or long-term, low-dose protracted infusion of 5-FU, since these regimens have shown the most favorable toxicity spectrum and produced the longest survival times. Future research will also focus on the evaluation of various methods of delivery of 5-FU, including oral administration of the drug in combination with compounds that can modify its catabolism.     

Combination chemotherapy of continuous infusion 5-fluorouracil and daily low-dose cisplatin in advanced gastrointestinal and lung adenocarcinoma

Continuous intravenous infusion (c.v.i.) of 5-fluorouracil (5-FU) plus daily low-dose cisplatin (CDDP) was evaluated in 45 patients with advanced and recurrent unresected colorectal, lung, gastric and pancreatic adenocarcinoma. 5-FU was given at a dose of 320 mg/m2/day, c.v.i. for 4 weeks, and CDDP between 3.5 to 7 mg/m2/day, infused for one hour five times a week for 4 weeks. Patients received 1 to 3 cycles of treatment (average 1.5 cycle). Pancreatic cancer cases needed longer treatment periods (2.25 cycles). The response rate of colorectal cancer cases was 57.7% (15/26), pancreas cancer 40%, gastric cancer 62.5%, and lung cancer 66.7%. The overall response rate was 57.8%. No severe side effects occurred in any of these cases. These data indicate that this combination 5-FU + daily low-dose CDDP chemotherapy is effective in the treatment of advanced gastrointestinal and lung adenocarcinoma.     

Phase II trials of 5-fluorouracil and leucovorin in patients with metastatic gastric or pancreatic carcinoma

BACKGROUND: Previous trials in patients with colorectal carcinoma have indicated that enhancement of 5-fluorouracil (5-FU) by leucovorin (LV) can result in an improved response rate and increased survival. METHODS: Phase II trials were performed with patients who had either gastric or papcreatic adenocarcinoma with inetastases. Forty-one gastric carcinoma patients and 31 pancreatic carcinoma patients with measurable disease were treated with 5-FU, 425 mg/m2 intraveneosly (i.v.) on Days 1-5 plus LV, 20 mg/m2 i.v., on Days 1-5, reported at 4 and 8 weeks, and then every 5 weeks thereafter. RESULTS: The patients with metastatic gastric carcinoma had a median survival of 4.8 months. There was a 22% objective response rate, including a 4.9% complete response rate and a 17.1% partial response rate. Among the 31 patients with pancreatic carcinoma, there was a median survival of 5.7 months. No patients in this group showed a response. CONCLUSIONS: The response rate for patients with metastatic gastric adenocarcinoma was modest and this regimen may provide temporary palliation for some patients. However, 5-FU and LV treatment is ineffective against metastatic pancreatic carcinoma.     

5-Fluorouracil (5-FU) continuous intravenous infusion compared with bolus administration. Final results of a randomised trial in metastatic colorectal cancer

The aim of this Phase III, balanced randomised trial was to compare continuous intravenous infusion (CVI) of 5-FU with bolus (B) administration for metastatic colorectal cancer (CRC). One hundred and fifty-five non-pretreated patients were randomised to receive CVI 5-FU at a dose of 750 mg/m2/day (d), 7 d every 21 d (n = 77), or bolus 5-FU 500 mg/m2/d x 5 d every 28 d (n = 78). Incremental dose escalation at 50 mg per step was recommended in the absence of toxicity. All the patients had measurable metastatic disease (M), particularly, liver and a good performance status (WHO grade 0-1). Dose intensity was significantly higher in CVI than in the bolus group: 1369 mg/m2/week versus 558 mg/m2/week (P = 0.0001). Grade II-IV stomatitis was more frequent in the CVI group (31% versus 9%; P < 0.0001) as was hand and foot syndrome (14% versus 3%; P < 0.001). Diarrhoea (22% versus 12%) and grade III granulocytopenia (2% versus 6%) were comparable. Responses were more frequent in the CVI (26%) than in the bolus group (13%) (P < 0.04); progression-free survival was higher for the CVI group (P = 0.04), but there was no statistical difference in overall survival (median: 10 months (m) compared to 9 m), and 1 year survival (SD) 42% (6%) versus 40% (6%). In the multivariate analysis, survival was better for patients with a good PS, well-differentiated adenocarcinomas and a primary tumour without serosal extension. In conclusion, with a higher dose intensity, CVI 5-FU improved tumour control, but not overall survival.     

Cardiovascular disease prevention in eastern Europe

A phase II trial was conducted to evaluate the efficacy and toxicity of a modulation of 5-fluorouracil (5-FU) by methotrexate (MTX) (with leucovorin (LV) rescue) as first-line chemotherapy in patients with locally advanced (inoperable) or metastatic gastric carcinoma. From July 1993 through August 1996, 36 patients with advanced gastric carcinoma received a regimen that consisted of: MTX 200 mg/m2 diluted in 250 ml normal saline by intravenous infusion over 20 minutes at hour 0; 5-FU 1,200 mg/m2 intravenous push injection at hour 20. Beginning 24 hours after MTX administration all patients received LV 15 mg/m2 intramuscularly every 6 hours for six doses. Cycles were repeated every 15 days. One patient was not assessable for response. Objective regression was observed in 15 of 37 patients (43%; 95% confidence interval, 26%-60%). One patient (3%) achieved complete response and 14 (40%) achieved partial response. No change was recorded in 14 patients (40%) and progressive disease was noted in six patients (17%). The median time to treatment failure was 7 months and the median survival was 12 months. Toxicity was within acceptable limits but one therapy-related death resulting from severe leukopenia occurred. The dose-limiting toxicity was mucositis. Five episodes of grade 3 or 4 stomatitis were observed and caused dosage modifications of MTX and 5-FU. Biochemical modulation of 5-FU by MTX appears as an attractive modality in patients with advanced gastric cancer. Further investigation both in experimental and clinical fields is needed to clearly define its role and to design the best modulatory strategy.     

Late phase II study of novel oral fluoropyrimidine anticancer drug S-1 (1 M tegafur-0.4 M gimestat-1 M otastat potassium) in advanced gastric cancer patients

S-1 is a novel oral anticancer drug, composed of tegafur (FT), gimestat (CDHP) and otastat potassium (Oxo) in a molar ratio of 1:0.4:1, based on the biochemical modulation of 5-fluorouracil (5-FU). CDHP inhibits dihydropyrimidine dehydrogenase (DPD), an enzyme which degrades 5-FU, and maintains prolonged 5-FU concentrations in the blood and tumours. Oxo is distributed in the gastrointestinal tract at a high concentration after oral administration and alleviates gastrointestinal toxicity due to 5-FU. S-1 improves the tumour-selective toxicity of 5-FU by the actions of two modulators, CDHP and Oxo. We conducted a late phase II clinical trial of S-1 as an open trial in patients with advanced gastric cancer, to confirm its antitumour effect and adverse reactions. 51 patients with advanced gastric cancer were enrolled in the trial. S-1 was administered orally twice daily after meals, at a standard dose of 80 mg/m2/day. One course consisted of consecutive administration for 28 days and 14 days' rest. Administration was repeated over four courses. A complete response was obtained in 1 patient and partial responses in 24 patients, producing a response rate of 49% (25/51) (95% confidence interval (CI) 35.9-62.3%). The incidence of adverse reactions was 78% (40/51) and that of adverse reactions of grades 3 and 4 was 20%. Adverse reactions of grades 3 and 4 included a decrease in the haematocrit, leucopenia, granulocytopenia, diarrhoea, malaise and proteinuria. No serious unexpected adverse reactions were observed. In conclusion, S-1 was effective and well tolerated in patients with advanced gastric cancer.     

A phase II trial of 5-fluorouracil, leucovorin, and carboplatin in patients with unresectable biliary tree carcinoma

BACKGROUND: Unresectable adenocarcinoma of the biliary tree are associated with a very poor prognosis. 5-fluorouracil (5-FU) combination regimens have produced objective response rates in approximately 10-20% of patients. Leucovorin increases the selective cytotoxicity of 5-FU. There also are encouraging reports of carboplatin in combination with 5-FU in other gastrointestinal tract malignancies. METHODS: Fourteen consecutive eligible patients were treated with a combination of carboplatin, 300 mg/m2, intravenously (i.v.) on Day 1 only and 5-FU, 400 mg/m2, i.v. with leucovorin, 25 mg/m2, i.v. on Days 1-4. All patients were required to have a histologically confirmed diagnosis and measurable disease. Patients were evaluated for response, survival, and toxicity. RESULTS: A total of 48 cycles of therapy were delivered. The median survival was 5 months. One patient achieved complete remission and two others partial remission, for a total response rate of 21.4%. Four additional patients had stable disease for a median duration of 4 months. The therapy was well tolerated, with moderate myelosuppression as the main dose-limiting toxicity. CONCLUSIONS: The current combination regimen of leucovorin-modulated 5-FU with carboplatin is well tolerated with appropriate supportive care, produces significant objective responses in 21% of patients with biliary tree carcinoma, and should be considered for the treatment of this disease.     

Multidisciplinary treatment for colorectal liver metastases

The liver is an large immunologic organ with liver-associated macrophages (Kupffer cells) and natural killer-like primitive T cells. As these effectors are activated by interleukin-2 (IL-2), we have administered IL-2-based hepatic arterial infusion therapy in the treatment of patients with liver metastases of colorectal cancer. Patients with unresectable liver metastases were administered IL-2 7 x 10(5) U and 5-fluorouracil (5-FU) 250 mg/day as a continuous infusion, with a bolus injection of mitomycin C (MMC) 4 mg once weekly. Of 25 patients treated with this regimen, 19 achieved complete or partial responses (response rate: 76%). A multi-institutional randomized trial following the pilot study showed reproducible favorable results. For patients with resectable metastases, we have administered this infusion therapy for the prevention of cancer recurrence in the liver. Patients who had undergone curative hepatectomy received IL-2 1.4 to 2.1 x 10(6) U, 5-FU 250 mg and MMC 2 to 4 mg weekly for 6 months. Of 18 patients, 12 are alive disease-free, and the 5-year overall survival rate is 75%. Recurrent cancer has developed in 6 of the 18 patients; however, no patients had recurrence in the residual liver. We believe that liver metastases of colorectal can be controlled by this multimodal treatment.     

A pilot study of gamma-1b-interferon in combination with fluorouracil, leucovorin, and alpha-2a-interferon

The combination of IFN-alpha-2a (IFN-alpha) and IFN-gamma-1b (IFN-gamma) has been found to produce more than additive cytotoxicity with fluorouracil (5-FU) in HT 29 colon cancer cells due to enhanced DNA-directed effects. We therefore studied the combination of IFN-gamma with IFN-alpha, 5-FU, and leucovorin (LV) in a clinical trial. Fifty-three patients received an initial cycle of 5 million units (MU)/m2 IFN-alpha s.c. on days 1-7 with 500 mg/m2 LV and 370 mg/m2 5-FU i.v. on days 2-6. IFN-gamma was then added once tolerable doses of 5-FU and IFN-alpha were established for each patient. IFN-gamma was administered at one of six dose levels between 0.3-4.8 MU/m2 s.c. on days 1-7. This design permitted comparison of the clinical toxicity and pharmacokinetics of 5-FU in two consecutive cycles in an individual treated with the same doses of 5-FU/LV/IFN-alpha in the absence and presence of IFN-gamma. In 43 matched patient cycles, the addition of IFN-gamma did not seem to worsen gastrointestinal toxicity, and skin toxicity tended to be milder. 5-FU clearance was higher in 14 cycles with IFN-gamma compared to the patient's prior cycle with the same doses of 5-FU/LV/IFN-alpha: 798 +/- 309 versus 601 +/- 250 ml/min/m2 (mean +/- SD; P = 0.04). In these 28 cycles, the median 5-FU clearance was significantly lower in 11 cycles that were complicated by more severe diarrhea: 524 versus 798 ml/min/m2 (grade 2 versus 0-1; P = 0. 0032). Overall, 38% and 26% of patients had grade 3-4 diarrhea and mucositis. Dose reductions of IFN-gamma for chronic fatigue, malaise, or anorexia were ultimately required more frequently with >/=2.4 MU/m2 (P = 0.018), and the maximum tolerated dose of IFN-gamma was considered to be 1.2 MU/m2/ day. Objective responses were seen in 41% of 29 measurable colorectal cancer patients. Compared to our previous experience with 5-FU/LV/IFN-alpha, IFN-gamma and IFN-alpha appeared to have opposite effects on 5-FU clearance. These results suggest that any potential benefit of adding IFN-alpha to 5-FU/LV on this schedule may not depend solely on alterations in 5-FU clearance.     

Phase I clinical and pharmacological studies of benzylacyclouridine, a uridine phosphorylase inhibitor

Benzylacyclouridine (BAU, IND 039655) is a potent and specific inhibitor of uridine phosphorylase (UrdPase; EC 2.4.2.3). This enzyme plays a major role in regulating uridine homeostasis and also catalyzes the conversion of fluoropyrimidine nucleosides to their respective bases. Inhibition of UrdPase enzyme activity 18-24 h after 5-fluorouracil (5-FU) administration increased plasma levels of uridine and enhanced the therapeutic index of 5-FU by rescuing normal tissues. Moreover, in vitro preclinical studies have also shown that inhibiting UrdPase enzyme activity by BAU prior to administration of 5-FU increased cytotoxicity in a number of human cancer cell lines. A series of preclinical studies was performed in dogs and pigs to evaluate the pharmacological and pharmacodynamic properties of BAU. These data showed a sustained elevation in plasma uridine concentration in both animal models. The rapid degradation of a tracer dose of uridine into uracil was virtually arrested by BAU administered both p.o. or i.v. The t1/2 of BAU was 1.8-3.6 h in dogs, with bioavailability levels of 85% (30 mg/kg) and 42.5% (120 mg/kg). In pigs, the half-life varied from 1.6 to 2.3 h, with a bioavailability of 40% at 120 mg/kg. The drug was distributed into most tissues with a tissue: plasma ratio of approximately 0.7. On the basis of these preclinical studies, we performed a Phase I clinical trial of BAU in patients with advanced cancer. Patients received 200, 400, 800, and 1600 mg/m2 BAU as a single oral dose. Toxicities included grade 2 anemia, grade 1 fever, grade 1 fatigue, grade 1 constipation, and grade 1 elevation in alkaline phosphatase; none of these toxicities were observed to be dose dependent. The maximum tolerated dose and dose-limiting toxicity were not reached at the doses given. BAU plasma concentrations and area under the curve correlated linearly with the oral dose level. The pharmacokinetics of BAU were consistent with a first-order clearance, with average peak concentrations ranging from 19 microM (200 mg/m2) to 99 microM (1600 mg/m2) and tbeta1/2 ranging from 3.0 to 3.9 h at the four dose levels. Compared with baseline plasma uridine, treatment of patients with 200, 400, 800, and 1600 mg/m2 BAU increased peak uridine concentrations by 120, 150, 250, and 175%, respectively. On the basis of this clinical study, the suggested Phase II starting dose of BAU in combination with 5-FU is 800 mg/m2. Studies combining BAU with 5-FU and incorporating appropriate molecular and biochemical end points to assess the effects of this drug combination on tumor and/or surrogate tumor tissue are under way.     

Anosognosia and procedural learning in Alzheimer''s disease

Biochemical modulation of 5-fluorouracil (5-FU) by folinic acid (FA) increases the response rate in patients with metastatic colorectal cancer compared to 5-FU alone. Phase II trials also demonstrated increased efficacy when interferon was added to 5-FU. In two consecutive trials, 76 patients were treated on days 1-5 with FA 200 mg/m2 plus interferon 5 x 10(6) U/m2 and 5-FU 350 mg/m2 as intravenous bolus injection (n = 33, regimen A) or 5-FU 500 mg/m2 as 2-hour infusion (n = 43, regimen B), repeated every 3 weeks with individual 5-FU dose escalation in steps of 50 (regimen A) or 100 mg/m2 (regimen B). In regimen A 5-FU dose reduction to 300 mg/m2 due to toxicity was necessary in 49% of the patients; in regimen B a 5-FU dose of 600 mg/m2 or above was tolerated by 70% of the patients. Dose-limiting toxicity was severe mucositis and/or diarrhea. Objective responses were observed in 5 of 33 patients (15%) in regimen A (3-28%, 95% confidence interval) and 7 of 41 patients (17%) in regimen B (5-29%, 95% confidence interval). Median time to progression was 4.7 and 4.8 months, and median survival 9.9 and 11.4 months for regimens A and B, respectively. Prolonged 5-FU administration over 2 h allows the administration of a higher 5-FU dose compared to bolus injection with no apparent improvement in antineoplastic efficacy. The addition of interferon to the combination of 5-FU plus FA in this dose and schedule does not seem to improve the response rate but appears to increase treatment toxicity.     

Low-dose CDDP and continuous 5-FU treatment of advanced gastric cancer with peritoneal dissemination: a case with long disease-free survival

The patient was diagnosed to have gastric cancer (T3 N3 M0 P3, Stage IV b). We conducted LcFP therapy. CDDP, 7 mg/m2/day, day 1-5 i.v. drip for 2 hours, and 5-FU, 170 mg/m2/day, day 1-7, i.v. continuously for 24 hours. After 3 courses (one course: 4 LcFPs followed by one rest week), down staging (T3 N2 M0 P1. Stage IV a) and improvement of performance status were obtained, and then surgical resection was undertaken. After operation one course of LcFP therapy served as adjuvant chemotherapy. The patient has survived over one year and 8 months to date in a tumor-free condition. LcFP therapy promises to be useful in the clinical management of advanced gastric cancer.     

Anti-glomerular basement membrane (GBM)-antibody-mediated disease with normal renal function

The purpose of this study was to compare the objective response rate, duration of remission, and survival of 5-fluorouracil (5-FU) versus those of 5-FU plus levamisole in metastatic colorectal cancer using the same dose and schedule of these agents as in the North Central Cancer Treatment Group and intergroup studies of adjuvant therapy. Patients with no prior history of chemotherapy for metastatic disease were entered on this Hoosier Oncology Group randomized Phase III trial. Patients were stratified by Karnofsky performance status and presence or absence of liver metastases. They were randomized to receive 450 mg/m2 5-FU i.v. for 5 days followed by 15 mg/kg i.v. weekly (arm 1) or the same dose of 5-FU plus levamisole 50 mg p.o. every 8 h for 3 days every 2 weeks (arm 2). The duration of treatment for both arms was 26 weeks. From April 1990 to March 1995, 199 patients were entered. One hundred eighty-two patients, 91 in each arm, were fully evaluable. The response rates were 12% on arm 1 and 13% on arm 2. The median duration of response was 18 weeks on both arms. The median survival was 48 weeks on arm 1 and 41 weeks on arm 2 (P = 0.20). This study failed to show any improvement in survival, response, or duration of remission with the addition of levamisole to 5-FU in the treatment of metastatic colorectal cancer.