Metabolism and urinary excretion of a new quinoline anticancer drug, TAS-103, in humans.

1. TAS-103, a novel condensed quinoline derivative, has been developed as an anticancer drug targeting topoisomerases I and II. 2. The purpose of the present study was to characterize the metabolism and urinary excretion of TAS-103 after the intravenous infusion of a single dose to patients in Phase I clinical trials. 3. Five metabolites were detected using high-performance liquid chromatography (HPLC) photodiode array and a precursor scan by liquid chromatography mass spectrometry mass spectrometry (LC/MS/MS). 4. Structures of the five metabolites were determined using the results of enzymatic hydrolysis and the analysis of production mass spectra obtained by LC/MS/MS, and by comparing HPLC retention times and UV, mass and production mass spectra of authentic standards. 5. The metabolites were identified as demethyl-TAS-103 glucuronide (DM-TAS-103-G), TAS-103 glucuronide (TAS-103-G), TAS-103 glucuronide N-oxide (NO-TAS-103-G), demethyl-TAS-103 (DM-TAS-103) and TAS-103 N-oxide (NO-TAS-103). 6. The mean total amount of TAS-103 and TAS-103-G in urine was only 6.03% of the dose, suggesting that urine is not the main elimination route. TAS-103 was extensively metabolized, and a small percentage of the parent drug (0.41%) was found in urine.

Phase I trial of the matrix metalloproteinase inhibitor BAY12-9566 in patients with advanced solid tumors.

PURPOSE: Matrix metalloproteinases (MMPs) are a family of proteolytic enzymes that are believed to be involved in primary and metastatic tumor growth by degrading the basement membrane and changing the extracellular matrix to facilitate invasion of malignant cells and angiogenesis. Overexpression of MMPs has been documented in various solid tumors. BAY12-9566 is a selective inhibitor of MMPs, in particular MMP-2, -3. and -9. The purpose of this trial was to define the maximum tolerated dose (MTD), dose-limiting toxicities (DLT), safety profile, pharmacokinetics and pharmacodynamics of orally administered BAY12-9566 in patients with incurable solid tumors. METHODS: The starting dose of BAY12-9566 for this single institution, outpatient phase I study was 100 mg/day orally. Patients were allowed to receive drug for up to 12 months. A total of 27 patients with various solid malignancies including colorectal, breast, lung, cervical and ovarian cancers were enrolled at doses from 100 to 1,600 mg/day. Patients were evaluated weekly while on treatment. Relevant radiologic examination was performed every 8 weeks to document and follow sites of measurable or evaluable disease. RESULTS: Toxicities from BAY12-9566 included liver injury test abnormalities, anemia, shoulder and back pain. thrombocytopenia, mild nausea and fatigue, diarrhea, rash and deep vein thrombosis. No toxicity greater than grade III was observed. As doses were increased from 100 to 400 to 1,600 mg/day, even in divided doses, less than proportional increases in AUC were observed. At the highest dose level of 1600 mg/day, the day 29 AUC (3778.00 mg x h/l) remained similar to the day 29 AUC (3312.60 mg x h/l) at the dose level of 1200 mg/day. No responses were seen, but 14 patients remained on study with stable disease for 4 to 26 months. CONCLUSIONS: BAY12-9566 was well tolerated at doses as high as 800 mg orally twice daily. Although mild alterations in liver injury tests, platelet count and hematocrit were noted, these were not dose-limiting. The drug was well absorbed. However, the absence of proportional increases in AUC with doses greater than 800 mg and the achievement of Css in the range associated with biologic activity in preclinical models led to the selection of 800 mg twice daily for further evaluation in phase III trials.

A Phase I clinical and pharmacological evaluation of sodium phenylbutyrate on an 120-h infusion schedule.

PURPOSE: Sodium phenylbutyrate (PB) demonstrates potent differentiating capacity in multiple hematopoietic and solid tumor cell lines. We conducted a Phase I and pharmacokinetic study of PB by continuous infusion to characterize the maximum tolerated dose, toxicities, pharmacokinetics, and antitumor effects in patients with refractory solid tumors. PATIENTS AND METHODS: Patients were treated with a 120-h PB infusion every 21 days. The dose was escalated from 150 to 515 mg/kg/day. Pharmacokinetics were performed during and after the first infusion period using a validated high-performance liquid chromatographic assay and single compartmental pharmacokinetic model for PB and its principal metabolite, phenylacetate. RESULTS: A total of 24 patients were enrolled on study, with hormone refractory prostate cancer being the predominant tumor type. All patients were evaluable for toxicity and response. A total of 89 cycles were administered. The dose-limiting toxicity (DLT) was neuro-cortical, exemplified by excessive somnolence and confusion and accompanied by clinically significant hypokalemia, hyponatremia, and hyperuricemia. One patient at 515 mg/kg/day and another at 345 mg/kg/day experienced this DLT. Toxicity resolved < or =12 h of discontinuing the infusion. Other toxicities were mild, including fatigue and nausea. The maximum tolerated dose was 410 mg/kg/day for 5 days. Pharmacokinetics demonstrated that plasma clearance of PB increased in a continuous fashion beginning 24 h into the infusion. In individuals whose V(max) for drug elimination was less than their drug-dosing rate, the active metabolite phenylacetate accumulated progressively. Plasma PB concentrations (at 410 mg/kg/day) remained above the targeted therapeutic threshold of 500 micromol/liter required for in vitro activity. CONCLUSION: The DLT in this Phase I study for infusional PB given for 5 days every 21 days is neuro-cortical in nature. The recommended Phase II dose is 410 mg/kg/day for 120 h.

A phase I dose escalation and bioavailability study of oral sodium phenylbutyrate in patients with refractory solid tumor malignancies.

PURPOSE: Phenylbutyrate (PB) is an aromatic fatty acid with multiple mechanisms of action including histone deacetylase inhibition. Preclinically, PB demonstrates both cytotoxic and differentiating effects at a concentration of 0.5 mM. We conducted a Phase I trial of p.o. PB patients with refractory solid tumor malignancies to evaluate toxicity, pharmacokinetic parameters, and feasibility of p.o. administration. EXPERIMENTAL DESIGN: Twenty-eight patients with refractory solid tumor malignancies were enrolled on this dose-escalation to maximally tolerated dose trial. Five dose levels of PB were studied: 9 g/day (n = 4), 18 g/day (n = 4), 27 g/day (n = 4), 36 g/day (n = 12), and 45 g/day (n = 4). Pharmacokinetic studies were performed and included an p.o. bioavailability determination. Compliance data were also collected. RESULTS: The recommended Phase II dose is 27 g/day. Overall the drug was well tolerated with the most common toxicities being grade 1-2 dyspepsia and fatigue. Nonoverlapping dose-limiting toxicities of nausea/vomiting and hypocalcemia were seen at 36 g/day. The p.o. bioavailability of PB was 78% for all dose levels, and the biologically active concentration of 0.5 mM was achieved at all dose levels. Compliance was excellent with 93.5% of all possible doses taken. No partial remission or complete remission was seen, but 7 patients had stable disease for more than 6 months while on the drug. CONCLUSIONS: PB (p.o.) is well tolerated and achieves the concentration in vivo that has been shown to have biological activity in vitro. PB may have a role as a cytostatic agent and should be additionally explored in combination with cytotoxics and other novel drugs.

Impact of the putative differentiating agent sodium phenylbutyrate on myelodysplastic syndromes and acute myeloid leukemia.

Sodium phenylbutyrate (PB) is an aromatic fatty acid with cytostatic and differentiating activity against malignant myeloid cells (ID(50), 1-2 mM). Higher doses induce apoptosis. Patients with myelodysplasia (n = 11) and acute myeloid leukemia (n = 16) were treated with PB as a 7-day continuous infusion repeated every 28 days in a Phase I dose escalation study. The maximum tolerated dose was 375 mg/kg/day; higher doses led to dose-limiting reversible neurocortical toxicity. At the maximum tolerated dose, PB was extremely well tolerated, with no significant toxicities; median steady-state plasma concentration at this dose was 0.29 +/- 0.16 mM. Although no patients achieved complete or partial remission, four patients achieved hematological improvement (neutrophils in three, platelet transfusion-independence in one). Other patients developed transient increases in neutrophils or platelets and decrements in circulating blasts. Monitoring of the percentage of clonal cells using centromere fluorescence in situ hybridization over the course of PB administration showed that hematopoiesis remained clonal. Hematological response was often associated with increases in both colony-forming units-granulocyte-macrophage and leukemic colony-forming units. PB administration was also associated with increases in fetal erythrocytes. These data document the safety of continuous infusion PB and provide preliminary evidence of clinical activity in patients with myeloid malignancies.

Toxicity, efficacy, and pharmacology of suramin in adults with recurrent high-grade gliomas.

PURPOSE: To determine the toxicity, efficacy, and pharmacology of suramin in patients with recurrent or progressive recurrent high-grade gliomas. PATIENTS AND METHODS: Fifty adults were to receive suramin. However, if no responses were seen in the first ten patients, the study was to be terminated. A total of 12 patients were enrolled onto this trial. Ten patients had glioblastoma multiforme, and 11 had received prior nitrosoureas. RESULTS: Drug-related toxicities were modest and reversible. Three patients developed grade 3 to 4 neutropenia, constipation, diarrhea, or nausea. No CNS bleeding was observed. Median time to progression was 55 days (range, 17 to 242 days) and median survival was 191 days (range, 42 to 811 days). No partial or complete responses were seen at 12 weeks. However, the clinical outcome of three patients suggests that evidence of suramin activity may be delayed. One patient who "progressed" after 12 weeks of suramin had a subsequent marked reduction in tumor size and has maintained an excellent partial response for over 2 years without other therapy. Two others had disease stabilization and lived for 16 and 27 months. Pharmacokinetics from 11 patients revealed that all reached target suramin concentrations. CONCLUSION: This study demonstrates that suramin is well tolerated by patients with recurrent high-grade gliomas and may have efficacy in this disease. Its pharmacology seems unaffected by anticonvulsants. As a result of this data, suramin and radiation are now being administered concurrently to patients with newly diagnosed glioblastoma multiforme, with survival as the primary outcome.

Chemotherapy for human immunodeficiency virus-associated non-Hodgkin's lymphoma in combination with highly active antiretroviral therapy.

PURPOSE: This study investigated the efficacy, toxicity, and pharmacokinetic interactions resulting from simultaneous combination chemotherapy and highly active antiretroviral therapy (HAART) for patients with human immunodeficiency virus (HIV)-associated non-Hodgkin's lymphoma (NHL). In addition, the effects on viral load, CD4 counts, and opportunistic infections were examined with the use of combination chemotherapy combined with HAART. PATIENTS AND METHODS: Sixty-five patients with previously untreated and measurable disease at any stage of HIV-associated NHL of intermediate or high grade were entered onto this study at 17 different centers. The first 40 patients entered onto the study received reduced doses of cyclophosphamide and doxorubicin, combined with vincristine and prednisone (modified CHOP [mCHOP]), whereas the subsequent 25 patients entered onto the study received full doses of CHOP combined with granulocyte colony-stimulating factor (G-CSF). All patients also received stavudine, lamivudine, and indinavir. RESULTS: The complete response rates were 30% and 48% among patients who received mCHOP and full-dose CHOP combined with HAART, respectively. Grade 3 or 4 neutropenia occurred in 25% of patients receiving mCHOP and 12% of those receiving full-dose CHOP combined with G-CSF (25% v 12%). There were similar numbers of patients with grade 3 or 4 hyperbilirubinemia (12% and 17%), constipation and abdominal pain (18% and 17%), and transaminase elevation (48% and 52%) on the modified and full-dose arms of the study, respectively. Doxorubicin clearance and indinavir concentration curves were similar among patients on this study and historical controls, whereas cyclophosphamide clearance was 1.5-fold reduced as compared with control values. Human immunodeficiency virus (HIV) load declined from a median baseline value of 29,000 copies/mL to a median minimum value on therapy of 500 copies/mL. CONCLUSION: Either modified-dose or full-dose CHOP chemotherapy for HIV-NHL, delivered with HAART, is effective and tolerable.

Novel allogeneic granulocyte-macrophage colony-stimulating factor-secreting tumor vaccine for pancreatic cancer: a phase I trial of safety and immune activation.

PURPOSE: Allogeneic granulocyte-macrophage colony-stimulating factor (GM-CSF)-secreting tumor vaccines can cure established tumors in the mouse, but their efficacy against human tumors is uncertain. We have developed a novel GM-CSF-secreting pancreatic tumor vaccine. To determine its safety and ability to induce antitumor immune responses, we conducted a phase I trial in patients with surgically resected adenocarcinoma of the pancreas. PATIENTS AND METHODS: Fourteen patients with stage 1, 2, or 3 pancreatic adenocarcinoma were enrolled. Eight weeks after pancreaticoduodenectomy, three patients received 1 x 10(7) vaccine cells, three patients received 5 x 10(7) vaccine cells, three patients received 10 x 10(7) vaccine cells, and five patients received 50 x 10(7) vaccine cells. Twelve of 14 patients then went on to receive a 6-month course of adjuvant radiation and chemotherapy. One month after completing adjuvant treatment, six patients still in remission received up to three additional monthly vaccinations with the same vaccine dose that they had received originally. RESULTS: No dose-limiting toxicities were encountered. Vaccination induced increased delayed-type hypersensitivity (DTH) responses to autologous tumor cells in three patients who had received >or= 10 x 10(7) vaccine cells. These three patients also seemed to have had an increased disease-free survival time, remaining disease-free at least 25 months after diagnosis. CONCLUSION: Allogeneic GM-CSF-secreting tumor vaccines are safe in patients with pancreatic adenocarcinoma. This vaccine approach seems to induce dose-dependent systemic antitumor immunity as measured by increased postvaccination DTH responses against autologous tumors. Further clinical evaluation of this approach in patients with pancreatic cancer is warranted.

Intensified adjuvant combined modality therapy for resected periampullary adenocarcinoma: acceptable toxicity and suggestion of improved 1-year disease-free survival.

PURPOSE: (1) To determine the toxicity of an intensified postoperative adjuvant regimen for periampullary adenocarcinoma (pancreatic and nonpancreatic) utilizing concurrent 5-fluorouracil (5-FU), leucovorin (LV), dipyridamole (DPM), and mitomycin-C (MMC) combined with split-course locoregional external beam radiotherapy (EBRT) to 50 Gy. This was followed by 4 cycles of the same chemotherapy as adjuvant therapy. (2) To determine preliminary estimates of the overall and disease-free survival associated with the use of this regimen. (3) To compare the toxicities and early survival results of patients treated with the current regimen to those of patients who completed our prior trial of concurrent chemoradiation infusion with 5-FU/LV chemotherapy and regional nodal and prophylactic hepatic irradiation. METHODS: Postpancreaticoduodenectomy, patients received every 4 weeks bolus administration of 5-FU, (400 mg/m(2)), and LV, (20 mg/m(2), Days l-3), DPM (75 mg p.o., 4 times per day, Days 0-3, and every 8 weeks), MMC, (10 mg/m(2); maximum of 20 mg, Day l during EBRT). This was followed by 4 months of the same chemotherapy, beginning 1 month following the completion of EBRT. EBRT consisted of split-course 5000 cGy/20 fractions with a 2-week planned rest after the first 10 fractions (2500 cGy). RESULTS: From 4/96 to 6/99, 45 patients were enrolled and treated. Their experience constitutes the basis of this analysis. There were 29 patients with pancreatic cancer and 16 with nonpancreatic periampullary cancer. Seventeen patients had tumors of 3 cm or more, and 39 patients had at least 1 histologically involved lymph node. Thirteen patients had a histologically positive margin of resection. The mean time to start of treatment was 63 days following surgery. During chemoradiation therapy there were no Grade 3 or worse nonhematologic toxicities and 47% Grade 3 or Grade 4 hematologic toxicities of short duration. Following chemoradiation, during chemotherapy treatment only, there was one Grade 3 hepatic and one Grade 3 pulmonary toxicity which was nondebilitating (2% each case) and 42% Grade 3 or 4 hematologic toxicity. There were 2 episodes of neutropenic fever requiring admission and no treatment-related mortalities. One patient developed a mild case of HUS, which responded to standard management. One patient developed persistent shortness of breath (nondebilitating), and another patient had occasional dyspnea on exertion, both occurring after all therapy. The majority of patients complained of increased fatigue (Grade 1-2), greatest during the combined therapy and improving post all treatment. As of 6/23/99, 20 of 45 patients have relapsed, 13 in the liver. Twelve patients have died. Median follow-up for surviving patients is 14.3 months. Disease-free survival at 12 months following surgery is 66% (as compared to 25% in our prior study), and the median disease-free survival is 17 months (as compared to 8. 3 months in our prior study). Median survival has not yet been reached, but will be greater than 17 months. CONCLUSION: With a 14.3-month median follow-up, acute toxicity has been acceptable and manageable. Observed relapses were seen 9-13 months following surgical resection. Early survival analysis suggests a trend toward increased median disease-free survival (8.3 vs. 17 months), especially for patients with nonpancreatic periampullary adenocarcinoma.

A phase I and pharmacologic evaluation of the DNA intercalator CI-958 in patients with advanced solid tumors.

5-[(2-Aminoethyl)amino]-2-[2-(diethylamino)ethyl]-2H-[1]benzothiopyra no[4,3,2-cd]-indazol-8-ol trihydrochloride (CI-958) is the most active member of a new class of DNA intercalating compounds, the benzothiopyranoindazoles. Because of its broad spectrum and high degree of activity as well as a favorable toxicity profile in preclinical models, CI-958 was chosen for further development. The Phase I study described here was undertaken to determine the toxicity profile, maximum tolerated dose, and pharmacokinetics of CI-958 given as an i.v. infusion every 21 days. Adult patients with advanced refractory solid tumors who had adequate renal, hepatic, and hematological function, life expectancy, and performance status were eligible for this study. Written informed consent was obtained from all patients. Patients received a 1- or 2-h infusion of CI-958 at 21-day intervals. The starting dose was 5.2 mg/m2, and at least three patients were evaluated at each dose level before proceeding to a new dose level. A pharmacokinetically guided dose escalation design was used until reaching a predetermined target area under the plasma concentration versus time curve (AUC), after which a modified Fibonacci scheme was used. Forty-four patients (21 men and 23 women; median age, 59 years) received 162 courses of CI-958. Neutropenia and hepatorenal toxicity were the dose-limiting toxicities, which defined the maximum tolerated dose of CI-958 to be 875 mg/m2 when given as a 2-h infusion every 21 days. There were no tumor responses. Two patients had stable disease for >250 days. The recommended Phase II dose is 560 mg/m2 for patients with significant prior chemotherapy and 700 mg/m2 for patients with minimal prior chemotherapy. Pharmacokinetic analysis of plasma and urine concentration-time data from each patient was performed. At the recommended Phase II dose of 700 mg/m2, mean CI-958 clearance was 370 ml/min/m2, mean AUC was 33800 ng-h/ml, and mean terminal half-life (t1/2) was 15.5 days. The clearance was similar at all doses, and plasma CI-958 AUC increased proportionally with dose, consistent with linear pharmacokinetics. The percentage reduction in absolute neutrophil count from baseline was well predicted by AUC using a simple Emax model. The pharmacokinetically guided dose escalation saved five to six dose levels in reaching the maximum tolerated dose compared with a standard dose escalation scheme. This may represent the most successful application to date of this dose escalation technique.

A prospective pharmacologic evaluation of age-related toxicity of adjuvant chemotherapy in women with breast cancer.

Despite increasing evidence of benefit from adjuvant chemotherapy, older women with breast cancer are commonly given less aggressive treatment than younger patients. Conflicting prior data regarding age-related toxicity prompted this prospective study. Forty-four women (aged 35-79 years) with early-stage breast cancer were treated with four cycles of adjuvant therapy with doxorubicin 60 mg/m2 i.v. and cyclophosphamide 600 mg/m2 i.v. every 21 days. They were monitored for myelosuppression, cardiotoxicity, and decrease in quality of life. Pharmacokinetics were analyzed using cycle 1 plasma samples. Bone marrow granulocyte and macrophage colony-forming units (CFU-GM) were assayed in vitro for dose response to 4-hydroperoxycyclophosphamide and doxorubicin before cycle 1. There was moderate evidence of age-related decrease in nadir absolute neutrophil count (ANC) when age was viewed as a continuous variable. On average there was a 10/microliter drop in cycle 1 nadir ANC for every year increase in age (p = 0.02). However, when age was viewed as a categorical variable (age < 65 vs. > or = 65 years), a similar proportion of women in each group reached an ANC < 100 (18% vs. 19%). Neither neutropenic complications, alteration in cardiac function, nor change in quality of life scores were significantly age related (p > 0.12). Pharmacokinetic analyses did not demonstrate age-related differences in the clearance of either doxorubicin or cyclophosphamide (p > 0.8). Pharmacodynamic analysis of individual patient bone marrow progenitor cell sensitivity did not reveal any correlation with age (p > 0.48). In women undergoing adjuvant therapy for breast cancer, no clinically significant age-related trends in toxicity were observed. These data suggest that older age alone should not exclude patients from receiving adjuvant therapy with doxorubicin and cyclophosphamide.

Novobiocin in combination with high-dose chemotherapy for the treatment of advanced breast cancer: a phase 2 study.

We conducted the first phase 2 and pharmacologic study to evaluate the combination of novobiocin (a coumeromycin antibiotic that has been shown to augment alkylating agent cytotoxicity in experimental models) and high-dose cyclophosphamide and thiotepa followed by autologous marrow support in women with chemosensitive advanced breast cancer. Its aims were (1) to determine progression-free survival (PFS) and overall survival (OS), (2) to evaluate the pharmacokinetics of cyclophosphamide and thiotepa, and (3) to measure the ability of novobiocin to reverse alkylator drug resistance in vitro. Forty-one women with chemotherapy-responsive advanced breast cancer received cyclophosphamide (4 g/m2) for peripheral blood stem cell mobilization (treatment 1) followed by high-dose cyclophosphamide (1.5 g/m2 per day for 4 days), thiotepa (200 mg/m2 per day for 4 days), and novobiocin (4 g/day orally for 7 days) (treatment 2) and autologous marrow support. The median PFS was 10 months (range, 0.2-70.6 months) and OS, 21.5 months (range, 0.2-70.6 months). There was no statistically significant relationship between PFS or OS and area-under-the-curve values of cyclophosphamide, thiotepa, or 4-hydroxycyclophosphamide. Patient plasma samples (n = 12) obtained during novobiocin therapy were able to reverse alkylator drug resistance in an in vitro colony-forming assay. Correlative laboratory studies in an in vitro model system demonstrated that patient plasma after novobiocin treatment resulted in the magnitude of resistance reversal that had been predicted by prior preclinical experiments. Clinically, however, this activity of novobiocin did not translate into a substantial increase in PFS or OS compared with historical controls treated with high-dose alkylator therapy alone.

Clinical potential of matrix metalloprotease inhibitors in cancer therapy.

Matrix metalloproteases (MMP) are a family of enzymes that contribute to the degradation of the extracellular matrix. The destruction of the extracellular matrix eventually leads to tumour invasion, metastasis and angiogenesis. Realising this mechanism of action, there is tremendous potential for inhibitors of MMP in cancer therapy. Extensive preclinical data have shown that administration of matrix metalloprotease inhibitors (MMPI) to different animal models results in a reduction in primary tumour growth as well as in the number and size of metastatic lesions. Based on promising preclinical studies, synthetic MMPI have been developed and taken into clinical trials. These include marimastat, BAY- 129566, CGS-27023A, prinomastat (AG-3340), BMS-275291 and metastat (COL-3). These drugs are all in different stages of clinical development, ranging from phase I to III. In general, musculoskeletal problems, such as joint stiffness and pain in hands, arms and shoulders seem to affect most patients in varying degrees, depending on the dose and type of compound administered. In addition to single agent therapy, several MMPI have entered trials of combination therapy. The objective of combining chemotherapy with an MMPI is to potentiate tumour cytotoxicity as well as to reduce the size and number of metastatic lesions. Several compounds have entered phase III combination therapy trials, but it is still too early to report any data. There is ongoing research in correlating biological endpoints, such as levels of MMP and markers of angiogenesis with clinical response. As the field of MMP and their inhibitors continues to mature, its role in cancer therapeutics will be better defined.

Population pharmacokinetic model for topotecan derived from phase I clinical trials.

PURPOSE: To characterize the pharmacokinetics of topotecan in a population model that would identify patient variables or covariates that appreciably impacted on its disposition. PATIENTS AND METHODS: All data were collected from 82 patients entered in four different phase I trials that were previously reported as separate studies from 1992 to 1996. All patients received topotecan as a 30-minute constant-rate infusion on a daily-times-five schedule and were selected for this study because their daily dose did not exceed 2.0 mg/m(2). Among the 82 patients were 30 patients classified as having renal insufficiency and 13 patients with hepatic dysfunction. The population pharmacokinetic model was built in sequential manner, starting with a covariate-free model and progressing to a covariate model with the aid of generalized additive modeling. RESULTS: A linear two-compartment model characterized total topotecan plasma concentrations (n = 899). Four primary pharmacokinetic parameters (total clearance, volume of the central compartment, distributional clearance, and volume of the peripheral compartment) were related to various combinations of covariates. The relationship for total clearance (TVCL [L/h] = 32.0 + [0.356(WT - 71) + 0.308(HT - 168.5) - 8.42(SCR - 1.1)] x [1 + 0.671 sex]) was dependent on the patients' weight (WT), height (HT), serum creatinine (SCR), and sex and had a moderate ability to predict (r(2) = 0.64) each patient's individual clearance value. The addition of covariates to the population model improved the prediction errors, particularly for clearance. Removal of 10 outlying patients from the analysis improved the ability of the model to predict individual clearance values (r(2) = 0.77). CONCLUSION: A population pharmacokinetic model for total topotecan has been developed that incorporates measures of body size and renal function to predict total clearance. The model can be used prospectively to obtain a revised and validated model that can then be used to design individualized dosing regimens.

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.

Intensified adjuvant therapy for pancreatic and periampullary adenocarcinoma: survival results and observations regarding patterns of failure, radiotherapy dose and CA19-9 levels.

PURPOSE: Primary endpoints were 1. To determine if, in the context of postoperative adjuvant therapy of pancreatic and nonpancreatic periampullary adenocarcinoma, continuous infusion (C.I.) 5-fluorouracil (5-FU) and leucovorin (Lv), combined with continuous-course external-beam radiotherapy (EBRT) to liver (23.4-27.0 Gy), regional lymph nodes (50.4-54.0 Gy) and tumor bed (50.4-57.6 Gy), followed by 4 months of C.I. 5-FU/Lv without EBRT could be given with acceptable toxicity. 2. To determine an estimate of disease-free and overall survival (DFS, OS) with this treatment in this context. Secondary endpoints were 1. To observe the effects of therapy at two different dose levels of irradiation, and 2. To observe for correlations among DFS, OS and CA 19-9 levels during therapy. METHODS: Patients received C.I. 5-FU 200 mg/m2 and Lv 5 mg/m2 Monday through Friday during EBRT, and 4 cycles of the same chemotherapy without EBRT were planned for each 2 weeks of 4, beginning 1 month following the completion of EBRT. Therapy was to begin within 10 weeks of surgery and patients were monitored for disease recurrence, toxicity, and CA 19-9 levels before the start of EBRT/5-FU/Lv, before each cycle of C.I. 5-FU/Lv, and periodically after the completion of therapy. There were two EBRT dosage groups: Low EBRT, 23.4 Gy to the whole liver, 50.4 Gy to regional nodes and 50.4 Gy to the tumor bed; High EBRT, 27.0 Gy to the whole liver, 54.0 Gy to regional nodes, and 57.6 Gy to the tumor bed. RESULTS: 29 patients were enrolled and treated (23 with pancreatic cancer, and 6 with nonpancreatic periampullary cancer). Of these, 18 had tumor sizes > or = 3 cm and 23 had at least one histologically involved lymph node; 6 had histologically positive resection margins. Mean time to start of EBRT/5-FU/Lv was 53 +/- 2 days following surgery. The first 18 patients were in the Low EBRT Group and the last 11 in the High EBRT Group. Toxicity was moderate and manageable, including a possible case of late radiation hepatitis. Median DFS was 8.3 months (pancreatic cancer patients 8.5 months) and OS was 14.1 months (pancreatic cancer patients 15.9 months). Among patients with pancreatic cancer, results were similar for the Low and High EBRT Groups (DFS: 8.3 vs. 8.6 months; OS: 14.4 vs. 16.9 months, respectively). With a mean follow up of 2.6 +/- 0.3 years for the surviving patients and a minimal follow-up of 2.5 years, 27 of 29 pts have relapsed and 25 pts have died. A rise in CA 19-9 levels preceded clinical relapse by 9.1 +/- 1.5 months. Time to first relapse by site showed inverse correlation with dose of radiotherapy to that site: peritoneal (5 +/- 1 month), hepatic (7 +/- 0.9 months), regional nodes/tumor bed (9.6 +/- 1.8 months). Mean postresection CA 19-9 level was 63.3 +/- 16.2 U/ml. Postresection CA 19-9 values did not correlate with survival, margin status, or with the identification of metastatic carcinoma in resected lymph nodes. However, among patients with histologically involved nodes in the resected specimen, postresection CA 19-9 values did correlate with the number of positive nodes identified (p = 0.05). CONCLUSIONS: Although toxicity was acceptable, survival results were not improved over those seen with standard adjuvant treatment. Most patients relapsed before the planned chemotherapy cycles were completed, or within 100 days thereof, suggesting disease resistance to C.I. 5-FU/Lv as used in this study. Although this regimen is not recommended for further study, the doses of EBRT utilized may be suitable for evaluation with other chemotherapy combinations. Postoperative CA 19-9 levels did not correlate with survival, but did correlate with the number of histologically involved lymph nodes found in the resected specimen among node-positive patients. Moreover, rising CA 19-9 levels anticipated ultimate clinical failure by 9 months.

Phase I/pharmacokinetic study of the topoisomerase I inhibitor GG211 administered as a 21-day continuous infusion.

BACKGROUND: Preclinical results support a prolonged schedule of administration for topoisomerase I inhibitors, and we have previously demonstrated the safety and activity of the novel water-soluble topoisomerase I inhibitor GG211 when given as a 72-hour continuous infusion to cancer patients. PATIENTS AND METHODS: In a three-center international phase I trial, 38 patients received GG211 doses from 0.3 to 0.5 mg/m2/day by continuous intravenous infusions for seven, 14, and 21 days. Patients' median performance status was 1; nearly half had colorectal cancer, and 35 patients had prior chemotherapy. RESULTS: The first patient cohort received 0.3 mg/m2/day for seven days with no significant toxicities. Subsequent cohorts received continuous infusions for 14 and 21 days at this dose level with only mild myelosuppression noted. Dose-escalation on the 21-day schedule was then performed. No dose-limiting toxicity occurred at the 0.4 mg/m2/day dose level. Thrombocytopenia was dose-limiting with 0.5 mg/m2/day dosing but was not cumulative. Other grade 3 4 toxicities included neutropenia, nausea, vomiting, diarrhea, and fatigue. Partial responses occurred with 21-day infusion in two patients with breast and ovarian cancer at the 0.3 and 0.4 mg/m2/day dose levels, respectively. Mean GG211 lactone Css ranged from 0.17 to 0.64 ng/ml. CONCLUSION: The maximum tolerated dose of GG211 administered as a 21-day continuous infusion is 0.4 mg/m2/day with antitumor activity noted at tolerable doses.

Absorption, metabolism, and excretion of 14C-temozolomide following oral administration to patients with advanced cancer.

The purpose of this study is to characterize the absorption, metabolism, and excretion of carbon 14-labeled temozolomide (14C-TMZ) administered p.o. to adult patients with advanced solid malignancies. On day 1 of cycle 1, six patients received a single oral 200-mg dose of 14C-TMZ (70.2 microCi). Whole blood, plasma, urine, and feces were collected from days 1-8 and on day 14 of cycle 1. Total radioactivity was measured in all samples. TMZ, 5-(3-methyltriazen-1-yl)imidazole-4-carboxamide (MTIC), and 4-amino-5-imidazole-carboxamide (AIC) concentrations were determined in plasma, and urine and plasma samples were profiled for metabolite/degradation products. Maximum TMZ plasma concentrations were achieved between 0.33 to 2 h (mean, 1.2 h), and half-life, apparent volume of distribution, and oral clearance values averaged 1.9 h, 17 liters/m2, and 104 ml/min/m2, respectively. A first-order absorption, one-compartment linear model, which included first-order formation of MTIC from TMZ and elimination of MTIC via degradation to AIC, and a peripheral distribution compartment for AIC, adequately described the plasma TMZ, MTIC, and AIC concentrations. MTIC systemic clearance was estimated to be 5384 ml/min/m2, and the half-life was calculated to be 2.5 min. Metabolite profiles of plasma at 1 and 4 h after treatment showed that 14C-derived radioactivity was primarily associated with TMZ, and a smaller amount was attributed to AIC. Profiles of urine samples from 0-24 h revealed that 14C-TMZ-derived urinary radioactivity was primarily associated with unchanged drug (5.6%), AIC (12%), or 3-methyl-2,3-dihydro-4-oxoimidazo[5,1-d]tetrazine-8-carboxyl ic acid (2.3%). The recovered radioactive dose (39%) was principally eliminated in the urine (38%), and a small amount (0.8%) was excreted in the feces. TMZ exhibits rapid oral absorption and high systemic availability. The primary elimination pathway for TMZ is by pH-dependent degradation to MTIC and further degradation to AIC. Incomplete recovery of radioactivity may be explained by the incorporation of AIC into nucleic acids.

Should pancreaticoduodenectomy be performed in octogenarians?

As the population in the United States ages, an increasing number of elderly patients may be considered for pancreaticoduodenal resection. This high-volume, single-institution experience examines the morbidity, mortality, and long-term survival of 727 patients undergoing pancreaticoduodenectomy between December 1986 and June 1996. Outcomes of patients 80 years of age and older (n = 46) were compared to those of patients younger than 80 years. In these older patients, pancreaticoduodenectomy was performed for pancreatic adenocarcinoma (n = 25; 54%), ampullary adenocarcinoma (n = 9; 20%) distal bile duct adenocarcinoma (n = 5; 11%), duodenal adenocarcinoma (n = 2; 4%), cystadenocarcinoma; (n = 2; 4%), cystadenoma (n = 1; 2%), and chronic pancreatitis (n = 2; 4%). When compared to the 681 concurrent patients younger than 80 years who were undergoing pancreaticoduodenectomy, the two groups were statistically similar with respect to sex, race, intraoperative blood loss, and type of pancreaticoduodenectomy performed. Patients 80 years of age or older had a shorter median operative time (6.4 hours vs. 7.0 hours; P = 0.02) but a longer postoperative length of stay (median = 15 days vs. 13 days; P = 0.01) and a higher complication rate (57% vs. 41%; P = 0.05) when compared to their younger counterparts. Pancreaticoduodenectomy in the older group resulted in a 4.3% perioperative mortality rate compared to 1.6% in the younger group (P = NS). In the subset of patients undergoing pancreaticoduodenectomy for periampullary adenocarcinoma (n = 495), patients 80 years of age or older (n = 41) had a median survival of 32 months and a 5-year survival rate of 19%, compared to 20 months and 27%, respectively, in patients younger than 80 years (n = 454; P = 0.77). These data demonstrate that pancreaticoduodenectomy can be performed safely in selected patients 80 years of age or older, with morbidity and mortality rates approaching those observed in younger patients. Based on these data, age alone should not be a contraindication to pancreaticoduodenectomy.