Allopurinol: intravenous use for prevention and treatment of hyperuricemia.

PURPOSE: To tabulate data obtained over a 21-year period to determine the efficacy and safety of an intravenous (IV) allopurinol preparation. PATIENTS AND METHODS: IV allopurinol was provided on a compassionate plea basis to patients of any age in whom xanthine oxidase inhibitor therapy was indicated as an adjunct to chemotherapy and for whom oral intake was restricted. Three hundred twenty-seven investigators at multiple hospitals in the United States treated 1,172 patients with IV allopurinol. The vast majority of these patients had a malignancy and were in danger of developing tumor lysis syndrome (TLS) and subsequent acute uric acid nephropathy (AUAN) and were unable to take oral allopurinol. Data referable to the time period of IV allopurinol administration were collected, collated, and analyzed retrospectively. There was no randomization. RESULTS: In patients initiating treatment for an elevated serum uric acid (SUA), the SUA normalized or improved in 87% of adult patients and normalized or improved in 95% of pediatric patients. IV allopurinol, administered prophylactically to patients at high risk of developing hyperuricemia and TLS, prevented an increase in SUA levels in 93% of adults and 92% of children. Toxicities caused by IV allopurinol were minimal and consisted of 10 instances of mild to moderate skin or allergic reactions. CONCLUSION: IV allopurinol is as efficacious and safe as oral allopurinol and will be of significant benefit to patients at risk of TLS and AUAN and unable to take oral medication.

Multicenter phase II study of weekly oral vinorelbine for stage IV non-small-cell lung cancer.

PURPOSE: We initiated a large multicenter phase II trial in stage IV non-small-cell lung cancer (NSCLC) to evaluate the activity and safety of an oral gelatin-based formation of vinorelbine. PATIENTS AND METHODS: Twenty-three centers participated in this uncontrolled phase II study, which accrued patients between August 1991 and March 1992. Eligible patients had previously untreated measurable or assessable stage IV NSCLC, age more than 18 years, and Karnofsky performance status > or = 70%. The treatment plan initially was to administer 100 mg/m2/wk of oral vinorelbine or 80 mg/m2/wk for patients who had received prior radiation therapy. After the observation of grade IV granulocytopenia in six of the first 25 patients, subsequent doses were reduced by 40 mg (one capsule) in all patients. RESULTS: One hundred sixty-two patients were treated: 138 with measurable and 24 with assessable disease. One hundred two patients were men and 60 women. The mean age was 62 years (range, 36 to 83). The overall response rate was 14.5% for patients with measurable disease (95% confidence interval, 9.3% to 21.7%). The median time to treatment failure (TTF) for all patients was 9 weeks. The median survival time was 29 weeks; the 1-year survival rate was 22%. Toxicities included grade 3 or 4 neutropenia in 40%, which was dependent on the vinorelbine dose. Other toxicities included mild to moderate nausea/vomiting, diarrhea, and stomatitis. The mean dose intensity of vinorelbine was 53 mg/m2. CONCLUSION: Oral vinorelbine administered once weekly is an active agent in stage IV NSCLC. The median survival time of 29 weeks is similar to that achieved with single-agent intravenous vinorelbine and more aggressive cisplatin-based combinations. Further studies of this compound in the palliative-intent care setting appear to be indicated.

Pharmacokinetic, bioavailability, and feasibility study of oral vinorelbine in patients with solid tumors.

PURPOSE: The feasibility of administering vinorelbine (Navelbine, Burroughs Wellcome Co, Research Triangle Park, NC), a semisynthetic vinca alkaloid with broad activity, as a liquid-filled gelatin capsule was evaluated in a bioavailability (F) and pharmacokinetic study. PATIENTS AND METHODS: Each of 17 cancer patients had pharmacokinetic studies performed after receiving vinorelbine 30 mg/m2 intravenously (IV), which is the maximum-tolerated dose (MTD) for weekly IV administration, and twice after receiving the oral formulation at a nominal dose of 100 mg/m2. Subsequently, these patients and 10 other subjects received the oral formulation at a dose of 100 mg/m2/wk to evaluate the feasibility of chronic oral administration. RESULTS: Plasma drug disposition was well described by a triphasic model. Mean central volume of distribution and steady-state volume of distribution (Vss) were large (0.66 +/- 0.46 L/kg and 20.02 +/- 8.55 L/kg, respectively); the mean harmonic terminal half-life (t1/2) was long (18 hours); and the high mean clearance (CI) rate (0.80 +/- 0.68 L/h/kg) approached hepatic blood flow. F was low (0.27 +/- 12), and absorption was rapid (mean time of maximum plasma concentration [Tmax], 0.91 +/- 0.22 hours). Absorption parameters after the first and second oral doses were similar, with mean F values of 0.27 +/- 0.14 and 0.25 +/- 0.11, respectively. Coefficients of variability (CVs) for F, maximum plasma concentration (Cmax), and Tmax were 32%, 42%, and 78%, respectively, indicating moderate intraindividual variability. The pharmacologic profile of this oral formulation indicates that there is a large first-pass effect. Neutropenia was the principal toxicity of oral vinorelbine. Grade 3 or 4 neutropenia occurred in 63% of patients, but only 11% developed neutropenia and infection. Nausea, vomiting, and diarrhea were also common with oral administration, but these effects were rarely severe and could be ameliorated by using a divided-dose schedule and/or prophylactic antiemetic and antidiarrheal agents. The mean nominal oral dose was 82 mg/m2, and the mean percentage of intended dose that was received was 92%. Although dose escalations were permitted for negligible toxicity, doses were not escalated to greater than 100 mg/m2/wk in any patient. Vinorelbine given as a liquid-filled gelatin capsule at 100 mg/m2 provided equivalent pharmacologic exposure as 30 mg/m2 IV. CONCLUSION: The oral administration of vinorelbine, specifically as a liquid-filled, soft gelatin capsule, is a feasible route of administration. Weekly oral dosing at 100 mg/m2 induces a consistent degree of myelosuppression, but the high frequency of grade 3 or 4 neutropenia, albeit brief and uncomplicated, warrants the recommendation of a slightly lower starting dose, ie, 80 mg/m2/d, for subsequent phase II evaluations, especially in heavily pretreated patients.

Phase I and pharmacologic study of oral fluorouracil on a chronic daily schedule in combination with the dihydropyrimidine dehydrogenase inactivator eniluracil.

PURPOSE: To determine the maximum-tolerated dose (MTD), toxicities, and pharmacokinetics of oral fluorouracil (5-FU) administered twice daily in combination with oral eniluracil, an inactivator of dihydropyrimidine dehydrogenase, administered for 28 days every 35 days. PATIENTS AND METHODS: Oral 5-FU 1.35 mg/m(2) twice daily was administered with oral eniluracil 10 mg daily for 14 to 28 days, followed by a 1-week rest period. Eniluracil was started 1 day before 5-FU. Patients then received escalated doses of oral 5-FU 1. 35 to 1.8 mg/m(2) twice daily with an increased dose of eniluracil 10 mg twice daily for 28 days. A reduced dose of 5-FU 1.0 mg/m(2) with eniluracil 20 mg twice daily was evaluated. RESULTS: Thirty-six patients with solid malignancies were enrolled onto the study. Diarrhea was the principal dose-limiting toxicity of oral 5-FU and eniluracil given on this chronic schedule. The recommended phase II dose is 5-FU 1.0 mg/m(2) twice daily with eniluracil 20 mg twice daily. Mean (SD) values for terminal half-life, apparent volume of distribution, and systemic clearance of 4.5 hours (0.83 hours), 19 L/m(2) (3.0 L/m(2)), and 51 mL/min/m(2) (13 mL/min/m(2)), respectively. An average of 77% of 5-FU was excreted unchanged in urine after 28 days of treatment. The mean (range) 5-FU C(SS,min) values achieved at the 1.0 mg/m(2) dose level were 22 ng/mL (8 to 38 ng/mL). CONCLUSION: Chronic oral administration of 5-FU with oral eniluracil is tolerable and produces 5-FU steady-state concentrations similar to those achieved with protracted intravenous administration of 5-FU on clinically relevant dose schedules. Eniluracil provides an attractive means of administering 5-FU on protracted schedules.

Pharmacokinetic, oral bioavailability, and safety study of fluorouracil in patients treated with 776C85, an inactivator of dihydropyrimidine dehydrogenase.

PURPOSE: To study the absolute bioavailability and pharmacokinetics of an oral solution of fluorouracil (5-FU) in patients treated with 776C85, an oral inactivator of dihydropyrimidine dehydrogenase (DPD), and to evaluate the feasibility of administering oral 5-FU and 776C85 on a multiple-daily dosing schedule. PATIENTS AND METHODS: Twelve patients with refractory solid tumors were enrolled onto this three-period study. In periods 1 and 2, patients were randomly assigned to treatment with 5-FU 10 mg/m2 on day 2 given by either the oral or intravenous (IV) route with oral 776C85 3.7 mg/m2/d on days 1 and 2. In period 3, patients received escalating doses of 5-FU (10 to 25 mg/ m2/d) orally for 5 days (days 2 to 6) with 776C85 3.7 mg/m2/d orally (days 1 to 7) every 4 weeks. Pharmaco-kinetic studies were performed in periods 1 and 2, and after the fifth oral dose of 5-FU in period 3. RESULTS: Twelve patients completed the bioavailability and pharmacokinetic studies. Following oral 5-FU 10 mg/m2, the bioavailability was 122% +/- 40% (mean +/- SD), the terminal half-life (t1/2 beta) was 4.5 +/- 1.6 hours, the apparent volume of distribution (V beta) was 21.4 +/- 5.9 L/ m2, and the systemic clearance (Clsys) was 57.6 +/- 16.4 mL/min/m2. A correlation was observed between oral 5-FU systemic clearance and calculated creatinine clearance (r = .74; P = .009). Multiple-daily dosing did not appear to affect the pharmacokinetics of oral 5-FU. Neutropenia was the principal toxicity of oral 5-FU and 776C85, precluding escalation of oral 5-FU to doses greater than 25 mg/m2/d for 5 days every 4 weeks with 776C85. CONCLUSION: The oral DPD inactivator 776C85 enables oral administration of 5-FU and may alter conventional 5-FU administration practices.

A phase I and pharmacokinetic study of 1843U89, a noncompetitive inhibitor of thymidylate synthase, in patients with advanced solid malignancies.

This study was performed to assess the feasibility of administering 1843U89, a potent, noncompetitive inhibitor of thymidylate synthase that does not require polyglutamation for activity, as a 2-min i.v. infusion daily for 5 days every 3 weeks, to determine whether folic acid supplementation ameliorates the toxic effects of 1843U89 and permits further dose escalation, and to recommend doses of 1843U89 administered without and with folic acid for further clinical evaluations. The study also sought to characterize the pharmacokinetic behavior of 1843U89 and to seek preliminary evidence of anticancer activity. Patients with advanced solid malignancies were treated with escalating doses of 1843U89 as a 2-min i.v. infusion daily for 5 days every 3 weeks. Initially, patients were treated in the absence of high-dose folic acid until dose-limiting toxicity was consistently noted. Next, patients were treated with escalating doses of 1843U89 preceded by 1000 mg of folic acid administered p.o. 30 min before each of the 5 daily doses of 1843U89. Patients (32) received 101 total courses of 1843U89 at doses ranging from 1 to 6 mg/m(2)/day with and without folic acid. At the 2 mg/m(2)/day dose level without folic acid, 2 of 7 new patients experienced dose-limiting toxicity, principally neutropenia, mucositis, and malaise in 3 of 11 courses. 1843U89 doses were further increased with folic acid to 6 mg/m(2)/day, but repetitive treatment was not feasible at this dose level because of an unacceptable high incidence of severe neutropenia and mucositis. Other toxicities included thrombocytopenia, rash, and fever. In contrast, repetitive treatment at the 5 mg/m(2)/day dose level was feasible. The pharmacokinetics of 1843U89 were neither dose dependent nor affected by folic acid. On day 1, clearance, terminal half-life, and steady-state volume of distribution values averaged 47.1 +/- 21.7 ml/min/m(2), 7.72 +/- 4.09 h, and 16.7 +/- 8.8 liter/m(2)/h, respectively. The results of the study indicate that the administration of 1843U89 as a 2-min infusion daily for 5 days every 3 weeks without and with folic acid is feasible at 1843U89 doses as high as 2 and 5 mg/m(2)/day, respectively. Because folic acid pretreatment results in no diminution of the antitumor activity of 1843U89 in preclinical studies and ameliorates the toxic effects of 1843U89 in both preclinical models and cancer patients, the therapeutic index of 1843U89 may be enhanced by folic acid pretreatment and, therefore, the development of 1843U89 with folic acid is warranted. However, the question of whether to administer 1843U89 at a dose of 2 mg/m(2)/day with folic acid, which is associated with negligible toxicity, or at its highest feasible dose with folic acid, 5 mg/m(2)/day, should be addressed in appropriately designed trials.

A summary of vinorelbine (Navelbine) safety data from North American clinical trials.

Extensive clinical experience has been obtained with the antineoplastic agent vinorelbine (Navelbine; Burroughs Wellcome Co, Research Triangle Park, NC; Pierre Fabre Médicament, Paris, France) in Europe and elsewhere. This experience recently has been supplemented by three clinical trials of patients with advanced non-small cell lung cancer or breast cancer conducted in North America. Data from these trials indicate that vinorelbine is safe and well tolerated in the outpatient population. Granulocytopenia is the dose-limiting toxicity. Although the incidence of this condition is high among vinorelbine-treated patients, it is uncommonly associated with severe complications. Elevations in alkaline phosphatase levels are seen in the majority of patients, but this effect may be due in part to liver and bone metastases. Nonhematologic toxicities are mostly mild or moderate. Injection site reactions have been noted in some patients, but improved administration techniques may help reduce the incidence of this effect. Gastrointestinal and respiratory effects are seldom severe and usually respond to treatment. Drug-associated neurotoxicity occurs less often than with other commonly used vinca alkaloid compounds. Overall, vinorelbine is associated with few severe toxicities, which for the most part, are easily managed. Thus, this agent seems well suited for use in the outpatient treatment of non-small cell lung and breast cancers.

The effects of food and divided dosing on the bioavailability of oral vinorelbine.

The effects of food and divided dosing on the bioavailability of a liquid-filled gelatin capsule formulation of vinorelbine (Navelbine), a semisynthetic vinca alkaloid with broad clinical activity, was evaluated in patients with advanced solid tumors. A group of 13 patients were randomized to treatment with the oral formulation at the recommended phase II dose of 80 mg/m2 per week either in the fasting state or after ingestion of a standard meal. Patients were treated 1 week later in the alternate state relative to their first dose. The effects of divided dosing were assessed during the 3rd week, at which time vinorelbine was administered in two divided doses. After the completion of pharmacokinetic and bioavailability studies, patients received the oral formulation at a dose of 80 mg/m2 per week in two divided doses to evaluate the feasibility of chronic oral drug administration. Both manipulations resulted in small, albeit statistically significant, reductions in the relative bioavailability of this oral formulation. The relative bioavailability decreased by 22 +/- 28% when treatment followed the ingestion of a standard meal, possibly due to a delay in gastrointestinal transit time. The mean time of maximum plasma concentration (Tmax) increased from 1.3 +/- 1.6 h in the fasting state to 2.5 +/- 1.6 h in the fed state, although this difference was not statistically significant. Similarly, the relative bioavailability declined by 16 +/- 51% when vinorelbine was administered in two divided doses. An analysis of dose proportionality revealed disproportionate increases in dose-normalized Cmax and AUC values with single oral doses above 120 mg, which may account for this phenomenon. The high clearance of vinorelbine, which approaches hepatic blood flow, and the lack of dose proportionality after oral administration, indicate that there is a large first-pass effect which may be saturable, or nonlinear, above single doses of 120 mg. In addition, the toxicological and pharmacological characteristics of oral vinorelbine indicate that treatment after a standard meal or on a divided dosing schedule is safe. Chronic oral administration of the agent in two divided doses was also well tolerated. However, the small reduction in the relative bioavailability following the ingestion of a standard meal and with divided dosing suggest the need for further pharmacodynamic studies to determine if reductions in drug exposure of this magnitude may portend diminished antitumor activity.

Phase I clinical and pharmacology study of 502U83 given as a 24-h continuous intravenous infusion.

502U83 is an arylmethylaminopropanediol that displays significant antitumor activity in a number of murine and human tumor-model systems. In the present phase I study, a 24-h continuous intravenous infusion of this agent was given every 28 days to patients with advanced or refractory solid tumors. In all, 46 patients received a total of 96 cycles of 502U83 at doses ranging from 25 to 8,000 mg/m2. No significant hematologic, gastrointestinal, or neurologic toxicity was observed. At doses of 2,000 mg/m2 and higher, prolongation of the corrected QT interval on ECG was evident in most patients but was completely reversible, was not associated with arrhythmias, and was not dose-limiting. Dose-limiting pulmonary toxicity characterized by acute onset of dyspnea, severe hypoxemia, interstitial pulmonary edema, and death occurred in three patients treated at the highest dose levels. Plasma concentrations of 502U83 and its metabolites were measured by high-performance liquid chromatography. The 502U83 maximal concentration (Cmax) and area under the concentration-time curve (AUC) were proportional to the delivered dose; however, substantial interpatient variability in total body clearance was noted at all dose levels. Significant conversion of 502U83 to two glucuronide metabolites was detected. Metabolite concentrations were highest in the three patients who succumbed to pulmonary toxicity, although the precise contribution of these metabolites to the observed toxic effects is unknown. In view of the unfavorable clinical profile of QTc prolongation and pulmonary toxicity produced by 502U83, further clinical development of this agent has been suspended.

Inability to escalate vinorelbine dose intensity using a daily x3 schedule with and without filgrastim in patients with metastatic breast cancer.

PURPOSE: Vinorelbine (Navelbine) is a semi-synthetic vinca alkaloid with documented activity in breast cancer. The major dose-limiting toxicity (DLT) when given weekly is myelosuppression with minimal neurologic toxicity. This phase I study attempted to define the maximally tolerated dose (MTD) and the DLT of vinorelbine on a daily x3 schedule with and without filgrastim support. METHODS: A total of 19 patients with stage IV breast cancer were enrolled in separate studies at Duke University Medical Center (DUMC) and the Dana-Farber Cancer Institute (DFCI). Eligible patients could have received up to two prior chemotherapy regimens in the metastatic setting and had to have an ANC > 1500/mm2, PLT > 100000 m3, creatinine < 2.0 mg/dl, bilirubin < 2.0 mg/dL, SGOT not more than three times normal, and performance status 0-1. Vinorelbine was administered using a daily x3 schedule every 3 weeks. The protocols were designed to study dose escalation with and without growth factor support. At DUMC, in the initial phase of the study, the starting dose was 15 mg/m2 per day and dose escalations of 5 mg/m2 were planned until DLT developed and the MTD was defined. DLT was defined as granulocytopenia < 500/mm3 for > 7 days, grade IV thrombocytopenia, febrile neutropenia, or grade III or greater nonhematologic toxicity. In the second phase of the study, growth factor support was given with vinorelbine at the MTD. Filgrastim at a dose of 5 microg/kg was started on day 4 of the 21-day cycle and was continued until the neutrophil count exceeded 10000 cells/ mm3. At DFCI, all patients received growth factor starting on day 4 and the starting dose of vinorelbine was 25 mg/m2. RESULTS: At DUMC, DLT was seen at 20 mg/m2 in three of three patients and included febrile neutropenia, grade IV neutropenia > 7 days, grade III neurotoxicity, and grade III vomiting. Despite the addition of filgrastim, DLT was again seen at 20 mg/m2 and included grade III neurotoxicity (jaw pain, abdominal pain, constipation, ileus) and grade IV mucositis. Three patients at DFCI were treated with vinorelbine at a dose of 25 mg/m2 with growth factor support, and two developed DLT including febrile neutropenia, neutropenia > 7 days, and grade III stomatitis. CONCLUSIONS: Our effort to escalate the dose intensity of vinorelbine on this schedule was not successful and was complicated by hematologic and nonhematologic toxicity. A daily x3 schedule of vinorelbine should not be pursued as an alternative treatment regimen in patients with previously treated metastatic breast cancer.

Clinical development of eniluracil: current status.

Eniluracil is a potent inactivator of dihydropyrimidine dehydrogenase (DPD), which is the first enzyme in the degradative pathway of systemically administered 5-fluorouracil (5-FU). Two completely oral regimens of eniluracil plus 5-FU are being evaluated in clinical trials: (1) a chronic schedule with both agents administered BID in a 10:1 ratio for 28 days of a 5-week course, and (2) a 5-day schedule of eniluracil once daily on days 1 through 7 and 5-FU once daily on days 2 through 6. The clinical development of eniluracil is being pursued in several tumor types, including colorectal cancer, breast cancer, and pancreatic cancer. Response rates achieved in a phase II study of the chronic schedule of oral eniluracil/5-FU in patients with colorectal cancer compare favorably with those obtained in trials of intravenous 5-FU and leucovorin, while results from other trials are awaited. Safety analysis for the 28-day schedule has revealed a low incidence of severe toxicities, particularly as compared with standard 5-FU regimens.

Phase II evaluation of the AMAP, 773U82 mesylate, in pancreatic cancer.

Pancreatic cancer is the fifth leading cause in cancer related death among adults in the United States. Thirty-thousand new cases of pancreatic cancer are diagnosed each year, most are metastatic at diagnosis and no effective systemic therapy is available. 773U82 mesylate is one of a series of compounds (arylmethylaminopropanediols-AMAPS) which was synthesized at the Wellcome Research Laboratories. AMAPS bind to DNA, show evidence of topoisomerase 2 inhibition and are active in a variety of murine and human preclinical screens. Based on these data a phase II trial of 773U82 mesylate administered at 800 mg/m2 daily x 3 at a 4 h infusion repeated every three weeks was carried out. Patients eligible for these trials had histologic proof of adenocarcinoma, good performance status, and normal organ function. This was a multi-institutional trial. Nineteen patients were entered; 15 patients were fully eligible and 4 were ineligible, but were evaluated. Thirteen patients were fully evaluable for response and no response was seen. Median time to progressive disease among eligible patients was 56 days. Toxicity of 773U82 mesylate was myelosuppression which was not prohibitive. 773U82 mesylate is not active in pancreatic cancer.

Phase I evaluation of 773U82-HCl in a two-hour infusion repeated daily for three days.

One of a novel series of compounds (AMAPS or arylmethylaminopropanediols), 773U82-HCl has shown significant antitumor activity in in vitro and in in vivo tumor systems, but has less animal CNS toxicity than the lead compound in the same series (crisnatol). This study was designed to evaluate the pharmacokinetics, qualitative and quantitative toxicities of 773U82-HCl and to determine the recommended phase II dose (MTD) of 773U82-HCl given as a short infusion daily for 3 days every 3 weeks. Twenty-nine patients with refractory malignancies received 79 courses over 9 dose levels during this study. Doses ranged from 50 to 1060 mg/m2/d x 3 days. Due to the possibility of local hemolysis with concentrations > 1.5 mg/ml, drug was administered in solutions containing < or = 1.5 mg/ml. Because large volumes were needed at the higher dose levels, the infusion duration was increased from 2 hours to 4 hours. Mild to moderate nausea, vomiting, fatigue, dizziness and headaches were observed. Myelosuppression was the dose limiting toxicity. The recommended phase II dose and schedule was determined to be 800 mg/m2/d x 3d every 3 weeks. 773U82-HCl plasma concentration-time data were analyzed using a two-compartment pharmacokinetic model. The t1/2 beta averaged 6 hours and the total body clearance was 75.9 L/hr/m2. The volume of distribution (Vdss) was large, averaging 470 L/m2.