Phase I trial and pharmacokinetic study of BMS-247550, an epothilone B analog, administered intravenously on a daily schedule for five days.

PURPOSE: The epothilones are a novel class of nontaxane microtubule-stabilizing agents. BMS-247550 is a semisynthetic analog of the natural product epothilone B. We conducted a phase I study administering BMS-247550 as a 1-hour intravenous infusion daily for 5 consecutive days every 21 days. PATIENTS AND METHODS: Twenty-one patients received BMS-247550 without filgrastim in the first cycle. An additional six patients were enrolled at a starting dose of 8 mg/m2/d with filgrastim support. Twenty-one of the 27 patients had received prior paclitaxel, docetaxel, or both. RESULTS: One hundred seven cycles were administered to 27 patients. The maximum-tolerated dose was 6 mg/m2 of BMS-247550 administered as a 1-hour intravenous infusion daily for 5 consecutive days every 21 days. Dose-limiting toxicity at a dose of 8 mg/m2/d was neutropenia with or without filgrastim support. Nonhematologic grade 3 toxicities included fatigue (seven cycles), stomatitis (two cycles), and anorexia (one cycle). The mean terminal half-life of BMS-247550 was 16.8 +/- 6.0 hours, the volume of distribution at steady-state was 798 +/- 375 L, and the clearance was 712 +/- 247 mL/min. Objective responses were observed in patients with breast, cervical, and basal cell cancer. Reductions in CA-125 levels were noted in patients with ovarian cancer. CONCLUSION: The recommended phase II dose of BMS-247550 on the daily schedule for 5 days is 6 mg/m2/d. Neutropenia was dose limiting, but higher doses were tolerated by a large fraction of patients with filgrastim support. Peripheral neuropathy was mild, even after multiple cycles of therapy, and was not dose limiting.     

Pediatric phase I trial and pharmacokinetic study of piritrexim administered orally on a five-day schedule

Piritrexim, a new nonclassical antifolate, was evaluated in a multiinstitutional phase I trial in children. The starting dose was 290 mg/m2/day, administered p.o. every 12 h for 5 consecutive days, with courses repeated every 21 days. Dose reduction, initially to 200 mg/m2/day and subsequently to 140 mg/m2/day, was required because dose limiting myelosuppression and mucositis were encountered at the 290- and 200-mg/m2/day dose levels. Non-dose limiting toxicities included transient elevations in liver function tests, mild nausea, and skin rashes. The maximum tolerated dose was 140 mg/m2/day for 5 days. Pharmacokinetic monitoring was performed at steady state during the first course. For the 140-, 200-, and 290-mg/m2/day dose groups, the mean +/- SE peak plasma concentrations were 5.3 +/- 0.84, 9.3 +/- 1.7, and 10.2 +/- 2.3 microM, respectively, and occurred at a median of 1.5 h following the p.o. dose. The mean area under the plasma concentration-time curves were 18.1 +/- 2.3, 45.4 +/- 8.9, and 56.9 +/- 16.3 microM.h, respectively. Absolute bioavailability in two patients who were also monitored following a single i.v. dose of 140 and 200 mg/m2/day of piritrexim was 35 and 93%, respectively. Dose limiting toxicities were observed in 9 of 10 patients with 12-h trough piritrexim concentrations greater than 0.5 microM, whereas only 2 of 7 patients with trough concentrations less than 0.5 microM experienced dose limiting toxicities. A limited pharmacokinetic sampling strategy that allowed the area under the plasma concentration-time curve to be accurately predicted from the 3- and 6-h plasma drug concentration was developed. The recommended dose for future phase II trials is 140 mg/m2/day administered p.o. every 12 h for 5 consecutive days. Pharmacokinetic monitoring at 3, 6, and 12 h postdose may be useful for estimating bioavailability and for predicting which patients are at greatest risk for developing toxicity.     

Development of an optimal sampling strategy for clinical pharmacokinetic studies of the novel anthracycline disaccharide analogue MEN-10755

Aim MEN-10755 is a novel anthracycline analogue that has shown an improved therapeutic efficacy over doxorubicin in animal models, especially in gynaecological and lung cancers and is currently under clinical development for the treatment of solid tumours. The aim of the project was to develop an optimal sampling strategy for MEN-10755 to provide an efficient basis for future pharmacokinetic/pharmacodynamic investigations.Methods Data from 24 patients who participated in a phase I clinical pharmacokinetic study of MEN-10755 administered as a short i.v. infusion were included. Individual pharmacokinetic values were calculated by fitting the plasma concentration data to a two-compartment model using nonlinear least-squared regression (KINFIT, Ed 3.5). Population pharmacokinetic analysis was carried out using (a) the traditional standard two-stage method (STS) based on all data (KINFIT-ALL), (b) the iterative two-stage Bayesian (IT₂B) population modelling algorithm (KINPOP), and (c) the STS method using KINFIT and using four optimally timed plasma concentrations (KINFIT-OSS4). Determinant (D) optimal sampling strategy (OSS) was used to evaluate the four most information-rich sampling times. The pharmacokinetic parameters V_c (l), k_el (h^–1), k₁₂ (h^–1) and k₂₁ (h^–1) calculated using KINPOP served as a model for calculation of four D-optimal sampling times. D-optimal sampling data sets were analysed using KINFIT-OSS4 and compared with the population model obtained by the traditional standard two-stage approach for all data sets (KINFIT-ALL).Results The optimal sampling times were: the end of the infusion, and 1.5 h, 3.8 h and 24 h after the start of the infusion. The four-point D-optimal sampling design determined in this study gave individual parameter estimates close to the basic standard estimates using the full data set.Conclusion Because accurate estimates of pharmacokinetic parameters were achieved, the four-point D-optimal sampling design may be very useful in future studies with MEN-10755.This study was supported by Menarini Ricerche S.p.A.     

Pediatric phase I trial, pharmacokinetic study, and limited sampling strategy for piritrexim administered on a low-dose, intermittent schedule.

Piritrexim, an orally administered, lipid-soluble antifolate, was evaluated in a multi-institutional phase I trial in children. The starting dose was 10 mg/m2/dose administered every 8 h daily for 5 days for 3 consecutive weeks, with dose escalations in increments of 5 mg/m2/dose. Eighteen patients (16 with metastatic sarcoma, 1 with acute lymphoblastic leukemia, and 1 with a brainstem glioma), 3.5-20 years of age, with malignancy refractory to therapy, were entered into the study. The dose-limiting toxicities (DLTs), which were myelosuppression and mucositis, occurred in 4 of 4 patients treated at the 25-mg/m2/dose level but in none of the patients treated at the 15- and 20-mg/m2/dose levels. The recommended dose for phase II trials is 20 mg/m2/dose. Pharmacokinetic monitoring was performed in 15 of the 18 children. The area under the concentration-time curve (AUC) was linearly related to the dose administered. Piritrexim was rapidly absorbed, with the median time to peak level occurring 1.5 h after an oral dose. The terminal half-life of piritrexim ranged from 1.5 to 4.5 h. A limited sampling strategy developed earlier, capable of predicting the AUC based on the plasma concentrations at 3 and 6 h after an oral dose, was prospectively tested in this trial and proved to be highly predictive of the AUC (r = 0.98, P = 0.0001). Pharmacodynamic-pharmacokinetic correlations were obtained after combining data from this and the prior phase I pediatric trial. Trough plasma piritrexim concentration strongly correlated with DLT (P = 0.0016). A trough plasma piritrexim concentration greater than 0.5 microM appeared to be predictive of toxicity. Eleven of 15 patients with trough concentrations exceeding this threshold experienced DLTs. Therapeutic drug monitoring may thus play an important role in adjusting the dose and schedule of piritrexim in future trials.     

Phase I clinical and pharmacokinetic study of trimetrexate using a daily x5 schedule

Trimetrexate (TMQ; NSC 352122) is a potent inhibitor of dihydrofolate reductase with good activity against murine i.p.-implanted B16 melanoma and colon 26 tumors. Preclinical antineoplastic activity, demonstrated schedule dependency, and data suggesting effectiveness against methotrexate-resistant cells prompted a Phase I clinical and pharmacokinetic study of trimetrexate using an i.v. daily x5 schedule. Forty-three good performance status patients were treated with 12 dose levels using daily doses varying from 0.5 to 15 mg/m2/d. Plasma and urine samples were obtained for pharmacokinetic analysis using a high-performance liquid chromatographic method. Myelosuppression was dose limiting and 15 mg/m2/d x5 was the maximum tolerated dose. White blood cell (WBC) and platelet toxicity were noted at doses of 1.6 mg/m2 and above. Median WBC and platelet nadirs occurred on approximately Days 11-12 with recovery by Days 15-18. Nonhematological toxicity included mucositis, nausea and vomiting, stomatitis, diarrhea, and rash. Evidence for antitumor activity was seen in seven patients. Trimetrexate elimination from plasma could be represented as either a bi- or triexponential process. Terminal elimination half-lives were in the range of 5-14 h in patients represented by a triexponential model. Approximately 10-20% of the dose administered was excreted in urine over a 24-h period. The recommended starting dose for patients in Phase II trials using the d x5 i.v. schedule is 8.0 mg/m2/d repeated every 21 days. Dose escalations may be possible depending on the extent of prior therapy and individual tolerance of the drug.     

Phase I clinical and pharmacokinetic trial of docetaxel and irinotecan administered on a weekly schedule

Background Docetaxel and irinotecan are synergistic agents with a broad spectrum of activity but overlapping myelosuppression. The study was designed to maintain dose intensity while limiting myelosuppression. The objectives of this study were to determine the maximal tolerated dose (MTD) of the combination of docetaxel and irinotecan administered weekly for four consecutive weeks every 42 days, to describe toxicities of this regimen, and to perform a pharmacokinetic analysis to evaluate changes in drug disposition as a function of dose as well as repeated dosing.Methods Adult patients with advanced solid tumors were treated with docetaxel followed by irinotecan. Doses of 30/50, 35/50, 35/66, 30/57, 30/65, 30/80 mg/m², respectively, were studied. Pharmacokinetics of docetaxel, irinotecan and SN-38 in plasma were determined on days 1 and 22 by a high-performance liquid chromatography (HPLC) assay.Results A total of 35 patients were treated. The MTD was docetaxel 30 mg/m² plus irinotecan 65 mg/m². Diarrhea was the dose-limiting toxicity; myelosuppression and other non-hematological toxicities were uncommon and mild. There were no significant differences in pharmacokinetic parameters between day 1 and day 22 (n=20). Five objective responses (breast, stomach and unknown primary) were observed among 30 evaluable patients. In addition, eight patients achieved stable disease.Conclusions The combination of weekly docetaxel and irinotecan is a well tolerated regimen and should be explored in phase II trials. This schedule maintains dose intensity and has limited myelosuppression.     

Phase I and pharmacokinetic study of triapine, a potent ribonucleotide reductase inhibitor, administered daily for five days in patients with advanced solid tumors.

PURPOSE: A Phase I study in patients with advanced cancer was conducted to determine the safety, pharmacokinetics, and maximum tolerated dose of Triapine, a new, potent small-molecule inhibitor of ribonucleotide reductase. EXPERIMENTAL DESIGN: Triapine was administered by 2-h i.v. infusion daily for 5 days. Courses were repeated every 4 weeks. The starting dose was 5 mg/m(2)/day, but was reduced to 2 mg/m(2)/day after the first patient developed a hepatic adverse event. The dose was subsequently escalated using a modified Fibonacci scheme in cohorts of 3-6 patients. After the 12 mg/m(2)/day dose level, the study design was amended to permit 100% dose escalation in single-patient cohorts until the first episode of a drug-related grade 2 adverse event or dose-limiting toxicity (DLT). On reaching a dose of 96 mg/m(2)/day, the study was amended to determine the safety and tolerability of the 96-mg/m(2) dose administered daily for 5 days every 2 weeks in an expanded cohort of patients. RESULTS: A total of 32 patients received treatment. During the dose escalation phase of the study, grade 2-4 drug-related adverse events were first observed at a dose of 96 mg/m(2)/day. Grade 3-4 leukopenia was the primary toxicity observed among four patients treated at this dose, which occurred in the week after treatment and resolved to grade 1 or lower by day 15. Fifteen patients were subsequently treated at the 96-mg/m(2) dose, daily for 5 days, with courses repeated every 2 weeks. The most common nonhematological toxicities for the latter schedule were asthenia, fever, nausea and vomiting, mucositis, decreased serum bicarbonate, and hyperbilirubinemia, and were predominantly grade 1-2 in severity and rapidly reversible. Hematological toxicity on the every-other-week schedule consisted of leukopenia (grade 4 in 93% in at least one course) and anemia (grade 2 in 71%, grade 3 in 22%). Thrombocytopenia was less common and was grade 3-4 in severity in only 22%. Triapine showed linear pharmacokinetic behavior although interpatient variability was relatively high. Peak concentrations at the 96-mg/m(2)/day dose averaged 8 microM, and the mean elimination T(1/2) ranged from 35 min to 3 h, with a median value of approximately 1 h. Cumulative urinary recovery averaged 1-3% of the administered dose, suggesting that the elimination of Triapine was primarily through metabolism. No partial or complete responses were observed. CONCLUSIONS: Triapine administered at a dose of 96 mg/m(2) by 2-h i.v. infusion daily for 5 days on an every-other-week schedule demonstrates an acceptable safety profile. Serum concentrations that surpass in vitro tumor growth-inhibitory concentrations are achieved for brief periods of time each day and are sufficient to produce myelosuppression, the expected consequence of ribonucleotide reductase inhibition. Phase II trials are indicated but will proceed with a daily-for-4-days schedule to reduce the incidence of grade 4 leukopenia. The safety profile also supports the initiation of Phase I combination trials with other anticancer agents.     

Clinical and pharmacological phase I study with accelerated titration design of a daily times five schedule of BBR3464, a novel cationic triplatinum complex

Objectives:To define the maximum tolerated dose (MTD), thetoxicity and pharmacokinetic profile of BBR3464, a novel triplatinum complex. Patients and methods:Fourteen patients with advanced solid tumorsnot responsive to previous antitumor treatments received BBR 3464 on a daily× 5 schedule every twenty-eighth day. The drug was given as a one-hourinfusion with pre-and post-treatment hydration (500 ml in one hour) and noantiemetic prophylaxis. The starting dose was 0.03 mg/m²/day. Amodified accelerated titration escalation design was used. Total and freeplatinum (Pt) concentrations in plasma and urine were assessed by ICP-MS ondays 1 and 5 of the first cycle. Results:Dose was escalated four times up to 0.17mg/m²/day. Short-lasting neutropenia and diarrhea of late onsetwere dose-limiting and defined the MTD at 0.12 mg/m². Nausea andvomiting were rare, neither neuro- nor renal toxic effects were observed.BBR3464 showed a rapid distribution phase of 1 hour and a terminal half-lifeof several days. At 0.17 mg/m² plasma Cmax and AUC on day 5 werehigher than on day 1, indicating drug accumulation. Approximately 10%of the equivalent dose of BBR3464 (2.2%–13.4%) wasrecovered in a 24-hour urine collection. Conclusions:The higher than expected incidence of neutropenia andGI toxicity might be related to the prolonged half-life and accumulation oftotal and free Pt after daily administrations. Lack of nephrotoxicity and thelow urinary excretion support the use of the drug without hydration. Thesingle intermittent schedule has been selected for clinical development.     

Phase I and pharmacokinetic study of topotecan administered orally once daily for 5 days for 2 consecutive weeks to pediatric patients with refractory solid tumors.

PURPOSE: We conducted a phase I trial of the injectable formulation of topotecan given orally once daily for 5 days for 2 consecutive weeks (qd x 5 x 2) in pediatric patients with refractory solid tumors. PATIENTS AND METHODS: Cohorts of two to six patients received oral topotecan at 0.8, 1.1, 1.4, 1.8, and 2.3 mg/m(2)/d every 28 days for a maximum of six courses. Twenty patients (median age, 10.6 years) received a total of 51 courses. Eight patients received topotecan capsules during course 2 only. RESULTS: Dose-limiting toxicity occurred at 2.3 mg/m(2)/d and consisted of prolonged grade 4 neutropenia (n = 2), grade 3 stomatitis as a result of radiation recall (n = 1), grade 3 hemorrhage (epistaxis) in the presence of grade 4 thrombocytopenia (n = 1), and grade 3 diarrhea in the presence of Clostridium difficile infection (n = 1). Dose-limiting, prolonged grade 4 neutropenia and thrombocytopenia occurred in one patient at 1.4 mg/m(2)/d. Infrequent toxicities were mild nausea, vomiting, elevated liver ALT or AST, and rash. The maximum-tolerated dosage was 1.8 mg/m(2)/d; the mean (+/- standard deviation) area under the plasma concentration-time curve for topotecan lactone at this dosage was 20.9 +/- 8.4 ng/mL. h. The population mean (+/- standard error) oral bioavailability of the injectable formulation was 0.27 +/- 0.03; that of capsules was 0.36 +/- 0.06 (P =.16). Disease stabilized in nine of 19 assessable patients for 1.5 to 6 months. CONCLUSION: Oral topotecan (1.8 mg/m(2)/d) on a qd x 5 x 2 schedule is well tolerated and warrants additional testing in pediatric patients.     

Phase I trial of perillyl alcohol administered four times daily continuously

Purpose Previous experience with perillyl alcohol (POH) was with a formulation of 500-mg capsules each containing 250 mg POH and soybean oil. This formulation resulted in the ingestion of large amounts of soybean oil (>10 g/day). Dose-limiting toxicities (DLT) were primarily gastrointestinal. Prior studies also showed no further increase in POH metabolite concentrations with doses of >1600 mg/m². Therefore, a new formulation of POH was developed (700 mg containing 675 mg POH) in an effort to improve dose and metabolite concentrations delivered and toxicity encountered with chronic dosing.Experimental design Eligible patients had refractory solid malignancies. Dose escalation occurred in cohorts of three at the dose levels/dose of 1350 mg, 2025 mg, 2700 mg, 3375 mg and 4050 mg, administered orally four times a day in a 28-day cycle.Results A group of 19 patients were enrolled. One DLT occurred at dose level 5. This cohort was expanded to six patients, and no further DLT occurred. The maximum tolerated dose was not reached. The predominant toxicity was gastrointestinal. Nausea and vomiting occurred in 63% of patients (12/19, grade 1 in 10). The same proportion of patients (12/19) experienced heartburn and indigestion, primarily grade 1. Although the side effects were mild in nature, three patients withdrew from treatment, citing intolerable gastrointestinal toxicity. The AUCs of POH metabolites did not appear to increase from level 1 to level 2 or change significantly from day 1 to day 29. Inter- and intrapatient variability in metabolite levels was observed.Conclusions This reformulation of POH appears to be an improvement upon the prior formulation, by reducing the number of capsules ingested and the degree of gastrointestinal toxicity per dose. It does not appear to offer any metabolite pharmacokinetic advantage. A dose of 2050 mg administered four times daily was easily tolerated. Higher doses can be administered but with increasing gastrointestinal toxicity that limits compliance.Abbreviations AUC Area under the curve - DHPA Dihydroperillic acid - DLT Dose-limiting toxicity - IGF Insulin-like growth factor - M6P Mannose-6-phosphate - MTD Maximum tolerated dose - PA Perillic acid - POH Perillyl alcohol - TGF Transforming growth factor - ULN Upper limit of normalThis work was supported by University of Wisconsin General Clinical Research Center Grant M01 RR 03186.     

Phase I and pharmacokinetic study of a daily times 5 short intravenous infusion schedule of 9-aminocamptothecin in a colloidal dispersion formulation in patients with advanced solid tumors.

PURPOSE: To determine the maximum-tolerated dose (MTD), dose-limiting toxicities (DLT), and pharmacokinetics of 9-aminocamptothecin (9-AC) in a colloidal dispersion (CD) formulation administered as a 30-minute intravenous (IV) infusion over 5 consecutive days every 3 weeks. PATIENTS AND METHODS: Patients with solid tumors refractory to standard therapy were entered onto the study. The starting dose was 0.4 mg/m(2)/d. The MTD was assessed on the first cycle and was defined as the dose at which > or = two of three patients or > or = two of six patients experience DLT. Pharmacokinetic measurements were performed on days 1 and 5 of the first cycle and on day 4 of subsequent cycles using high-performance liquid chromatography. RESULTS: Thirty-one patients received 104+ treatment courses at seven dose levels. The DLT was hematologic. At a dose of 1.3 mg/m(2)/d, three of six patients experienced grade 3 thrombocytopenia. Grade 4 neutropenia that lasted less than 7 days was observed in four patients. At a dose of 1.1 mg/m(2)/d, four of nine patients had grade 4 neutropenia of brief duration, which was not dose limiting. Nonhematologic toxicities were relatively mild and included nausea/vomiting, diarrhea, obstipation, mucositis, fatigue, and alopecia. Maximal plasma concentrations and area under the concentration-time curve (AUC) increased linearly with dose, but interpatient variation was wide. Lactone concentrations exceeded 10 nmol/L, the threshold for activity in preclinical tumor models, at all dose levels. Sigmoidal E(max) models could be fit to the relationship between AUC and the degree of hematologic toxicity. A partial response was observed in small-cell lung cancer. CONCLUSION: 9-AC CD administered as a 30-minute IV infusion daily times 5 every three weeks is safe and feasible. The recommended phase II dose is 1. 1 mg/m(2)/d.     

Phase I clinical and pharmacokinetic study of perillyl alcohol administered four times a day.

We conducted a phase I dose-escalation trial of perillyl alcohol (POH; NSC 641066) given p.o. on a continuous four times a day basis to characterize the maximum tolerated dose, toxicities, pharmacokinetic profile, and antitumor activity. Sixteen evaluable patients with advanced refractory malignancies were treated at the following doses: level 1 (L1), 800 mg/m2/dose; L2, 1200 mg/m2/dose; L3, 1600 mg/m2/dose. POH was formulated in soft gelatin capsules containing 250 mg of POH and 250 mg of soybean oil. The predominant toxicities seen were gastrointestinal (nausea, vomiting, satiety, and eructation), which were dose limiting. There appeared to be a dose-dependent increase in levels of the two main metabolites, perillic acid and dihydroperillic acid. No significant differences were seen whether the drug was taken with or without food. There was a trend toward decreasing metabolite levels on day 29 compared with days 1 and 2. Peak metabolite levels were seen 1-3 h post ingestion. Metabolite half-lives were approximately 2 h. Approximately 9% of the total dose was recovered in the urine in the first 24 h, the majority as perillic acid. Evidence of antitumor activity was seen in a patient with metastatic colorectal cancer who has an ongoing near-complete response of > 2 years duration. Several other patients were on study for > or = 6 months with stable disease. The maximum tolerated dose of POH given continuously four times a day was 1200 mg/m2/dose. Gastrointestinal toxicity was dose limiting, although significant interpatient variability in drug tolerance was seen.     

Phase I clinical and pharmacokinetic study of orally administered N4-palmitoyl-1-beta-D-arabinofuranosylcytosine

A phase I study of N4-palmitoyl-1-beta-D-arabinofuranosylcytosine (PLAC) was conducted in 88 patients; 36 with solid tumors and 52 with hematological malignancies, using 2 different schedules. Schedule 1 employed a single oral administration and Schedule 2, 5-day consecutive daily oral administration. In Schedule 1, the daily dose was initiated with 1 mg kg-1 which was escalated up to 24 mg kg-1 according to the modified Fibonacci's method. Side effects included nausea, vomiting and skin rashes, but myelosuppression was not seen within this dose range. In Schedule 2, the daily dose was started with 1 mg kg-1 which was escalated up to 24 mg kg-1. Major side effects were nausea, vomiting and anorexia, and mild myelosuppression was noted at 12 mg kg-1 or more. The dose-limiting toxicity was gastrointestinal toxicity, which appeared at 3.3 mg kg-1 or more and became frequent at 7 mg kg-1 or more. Pharmacokinetic study revealed that the plasma concentrations of PLAC and ara-C, obtained by the oral intake of 3.3 mg kg-1 or more of PLAC, were sufficient for these compounds to exert cytotoxic effects on various human leukemia cells in vitro. Based on these observations and plausible mechanism of action of PLAC, further clinical study should be carried out in a treatment schedule of considerably prolonged administration period with 3.3-6 mg kg-1 day-1 of PLAC.     

A Phase I clinical trial of ixabepilone (BMS-247550), an epothilone B analog, administered intravenously on a daily schedule for 3 days

BACKGROUND: The epothilones are a novel class of microtubule-stabilizing agents. Ixabepilone (BMS-247550; NSC 710428) is a semisynthetic analog of the natural product epothilone B. The authors conducted a Phase I study by administering ixabepilone to patients as a 1-hour intravenous infusion daily for 3 consecutive days every 21 days. METHODS: Twenty-six patients were enrolled and received ixabepilone at a starting dose of 8 or 10 mg/m(2) per day for 3 consecutive days. RESULTS: One hundred and nineteen cycles were administered to 26 patients. The maximum-tolerated dose was 8 mg/m(2) per day of ixabepilone administered as a 1-hour intravenous infusion daily for 3 consecutive days every 21 days. The dose-limiting toxicity (DLT) was neutropenia. Other nonhematologic Grade 3 toxicities included fatigue (3 cycles), hyponatremia (1 cycle), anorexia (1 cycle), ileus (1 cycle), stomatitis (1 cycle), and emesis (1 cycle). Prolonged disease stabilization was observed in patients with mesothelioma, ovarian carcinoma, and renal cell carcinoma. CONCLUSIONS: The recommended Phase II dose of ixabepilone on the daily schedule for 3 days was 8-10 mg/m(2) per day. Neutropenia was the DLT. Peripheral neuropathy was mild, even after multiple cycles of therapy, and was not dose limiting.     

Development of a pharmacokinetic limited sampling model for temozolomide and its active metabolite MTIC

Purpose To develop a pharmacokinetic limited sampling model (LSM) for temozolomide and its metabolite MTIC in infants and children.Methods LSMs consisting of either two or four samples were determined using a modification of the D-optimality algorithm. This accounted for prior distribution of temozolomide and MTIC pharmacokinetic parameters based on full pharmacokinetic sampling from 38 patients with 120 pharmacokinetic studies (dosage range 145–200 mg/m² per day orally). Accuracy and bias of each LSM were determined relative to the full sampling method. We also assessed the predictive performance of the LSMs using Monte-Carlo simulations.Results The four strategies generated from the D-optimality algorithm were as follows: LSM 1=0.25, 1.25, and 3 h; LSM 2=0.25, 1.25, and 6 h; LSM 3=0.25, 0.5, 1.25, and 3 h; LSM 4=0.25, 0.5, 1.25, and 6 h. LSM 2 demonstrated the best combination of low bias [0.1% (–8.9%, 11%) and 11% (4.3%, 15%)] and high accuracy [–1.0% (–12%, 24%) and 14% (7.9%, 37%)] for temozolomide clearance and MTIC AUC, respectively. Furthermore, adding a fourth sample (e.g., LSM 4) did not substantially decrease the bias or increase the accuracy for temozolomide clearance or MTIC AUC. Results from Monte-Carlo simulations also revealed that LSM 2 had the best combination of lowest bias (0.1±6.1% and –0.8±6.5%), and the highest accuracy (4.5±4.1% and 5.0±4.3%) for temozolomide clearance and MTIC apparent clearance, respectively.Conclusions Using data derived from our population analysis, the sampling times for a limited sample pharmacokinetic model for temozolomide and MTIC in children are prior to the temozolomide dose, and 15 min, 1.25 h and 6 h after the dose.This work was presented at AACR 2002 Annual Meeting.     

Antitumor activities and schedule dependence of orally administered MST-16, a novel derivative of bis(2,6-dioxopiperazine)

Summary We studied bioavailability, treatment schedule dependence, and therapeutic efficacy of orally administered MST-16, a novel derivative of bis(2,6-dioxopiperazine), against murine tumors and human tumor xenografts. The rate of its intestinal absorption was about 50%, and it was immediately metabolized to its parent compound, ICRF-154. Therapeutic efficacy of MST-16 was heavily dependent on the treatment schedule: 9 daily oral administrations and treatment every 4 h on day 1 only were much more effective against s.c.-implanted L1210 leukemia than a single dose or five daily administrations giving the same total dose. Orally administered MST-16 showed potent lifeprolonging effects (196%, 219% and 148%) in mice inoculated i.p. with P388, L1210 leukemia, and C-26 colon adenocarcinoma, respectively, but had no effect on B16 melanoma inoculated in the same way. MST-16 inhibited more than 80% growth of Lewis lung carcinoma, B16 melanoma, and C-38 colon adenocarcinoma implanted s.c., but had only a minor effect on M5076 fibrosarcoma. Lung metastasis of Lewis lung carcinoma was also effectively suppressed. Furthermore, MST-16 significantly inhibited growth of human colon, lung and breast cancers implanted s.c. in nude mice. We also made a kinetic analysis of the in vitro cell-killing effect by ICRF-154, the active form of MST-16 in vivo. It demonstrated a cell cycle phase-specific and time-dependent action, providing a reasonable explanation for the schedule-dependent therapeutic effect of MST-16.     

A phase I and pharmacokinetic study of ecteinascidin-743 on a daily x 5 schedule in patients with solid malignancies.

PURPOSE: The purpose of this study was to (a) assess the feasibility of administering ecteinascidin-743 (ET-743), a novel DNA minor-groove disrupting agent of marine origin, administered as a daily i.v. infusion for 5 days every 3 weeks; (b) recommend a dose for Phase II studies; (c) characterize its pharmacokinetic behavior; and (d) seek preliminary evidence of anticancer activity. EXPERIMENTAL DESIGN: Patients with advanced solid malignancies were treated with escalating doses of ET-743 as a daily 1-h i.v. infusion for 5 days every 3 weeks. Plasma and urine were sampled on both days 1 and 5 of the first course. Pharmacokinetic parameters were related to the principal toxicities. RESULTS: Forty-two patients were treated with 118 courses of ET-743 at doses ranging from 6 to 380 microg/m(2)/day. Elevations in hepatic transaminases were common at ET-743 dose levels > or =216 microg/m(2)/day, resolved rapidly, and were never dose limiting nor cumulative. Instead, hematological toxicity was the principal toxicity that precluded dose escalation. The maximum tolerated dose of ET-743 that could be administered repetitively was 325 microg/m(2)/day. Antitumor activity was noted in three patients with leiomyosarcoma and primary peritoneal and ovarian carcinomas. The pharmacokinetics of ET-743 were dose independent, and drug accumulation over the 5 days of treatment was modest, with the ratio of the area under the plasma-versus-time curve on day 5 to that on day 1 averaging 2.05. The volume of distribution at steady state was large (mean, 1037 liters/m(2)), and the mean terminal half life on day 5 was 26.81 h. CONCLUSIONS: The maximum tolerated dose of ET-743 that can be administered repetitively is 325 microg/m(2)/day daily x 5 every 3 weeks, which is recommended for disease-directed clinical trials. The acceptable toxicity profile of ET-743 on the divided-dose schedule evaluated in this trial, as well as the generally superior antitumor activity associated with divided-dose schedules in preclinical studies, provides a rationale for further evaluation of ET-743 on this administration schedule.     

Dose-finding phase I clinical and pharmacokinetic study of orally administered irinotecan in patients with advanced solid tumors.

PURPOSE: The aim of this study was to determine the daily maximum tolerated dose (MTD) and the dose-limiting toxicity for the following administration schedules: oral irinotecan given over 14 days every 3 weeks (part I) and oral irinotecan administered concomitantly with capecitabine over 14 days every 3 weeks (part II). In total, 42 patients (17 male and 25 female) with solid tumors refractory to standard therapy entered the study. EXPERIMENTAL DESIGN: Treatment in part I consisted of irinotecan administered orally as semisolid matrix capsules at doses of 25, 30, and 35 mg/m(2) once daily to confirm the MTD of our earlier study. In part II treatment, dose levels for irinotecan combined with capecitabine were 20/1,600, 25/1,600, 30/1,600, and 30/2,000 mg/m(2)/d. RESULTS: The median number of cycles administered per patient was 2.0 (range, 1-12) in part I and 2.0 (range, 1-13) in study part II. Gastrointestinal toxicities (grade 3 nausea, grades 3 and 4 vomiting, and grades 3 and 4 diarrhea) were dose limiting in both parts of the study. There were no grade 3 or 4 hematologic toxicities. The MTD was 30 mg/m(2)/d for irinotecan single agent and 30/1,600 mg/m(2)/d for the combination with capecitabine. Absorption of irinotecan was rapid, and peak concentrations of irinotecan and metabolite SN-38 were reached within 0 to 3 and 1.5 to 4.0 hours, respectively. CONCLUSIONS: In conclusion, oral irinotecan and capecitabine is feasible and well tolerated, and the recommended dose for phase II studies is 30/1,600 mg/m(2)/d administered daily for 14 days every 3 weeks.     

Development and validation of limited sampling models for topotecan lactone pharmacokinetic studies in children

Purpose: To develop and validate a pharmacokinetic limited sampling model (LSM) for intravenous and oral topotecan pharmacokinetic studies in children. Methods: Topotecan lactone concentration-time data from five trials were used to develop and validate LSM for intravenous and oral topotecan. Based on full sampling from one intravenous study (30 patients; 195 studies), a LSM for intravenous topotecan was determined using a modification of the D-optimality algorithm. For oral topotecan we used full sampling data from one oral topotecan study (27 patients; 47 studies) to develop an LSM. Accuracy and bias of each LSM were determined relative to the full sampling method. Predictive performance of the LSM was validated using additional data and Monte–Carlo simulations based on these data. Results: LSM for intravenous topotecan includes: 5 min, 1.5, and 2.5 h after the end of the 30 min infusion. The median accuracy (absolute predicted error) and bias (predicted error) are ≤8% and ≤6.1%, respectively. For oral topotecan, the optimal LSM includes: 15 min, 1.5, and 6 h. The median accuracy and bias are 6% and 4%, respectively. Conclusions: Our results indicate that the optimal sampling times for the intravenous LSM for topotecan in children consist of: predose, and 5 min, 1.5, and 2.5 h after the end of infusion. For oral topotecan the sample times are predose, 15 min, 1.5, and 6 h after dose administration. These LSM are invaluable to children receiving topotecan because it minimizes inconvenience and blood collection. Supported in part by US Public Health Service award CA23099 and the American Lebanese Syrian Associated Charities (ALSAC).