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Purpose: Tyrosine kinase inhibitors (TKI) that target MET signaling have shown promise in various types of cancer, including lung cancer. Combination strategies have been proposed and developed to increase their therapeutic index. Based on preclinical synergy between inhibition of MET and topoisomerase I, a phase I study was designed to explore the combination of topotecan with the MET TKI tivantinib.Methods: Eligible patients with advanced solid malignancies for which there was no known effective treatment received topotecan at doses of 1.0-1.5 mg/m2/day for five consecutive days in 21-day cycles with continuous, oral tivantinib given at escalating doses of 120-360 mg orally twice daily. Pharmacokinetic analyses of tivantinib were included. Circulating tumor cells (CTC) were collected serially to identify peripheral changes in MET phosphorylation.Results: The trial included 18 patients, 17 of whom received treatment. At the planned doses, the combination of topotecan and tivantinib was not tolerable due to thrombocytopenia and neutropenia. The addition of G-CSF to attenuate neutropenia did not improve tolerability. Greater tivantinib exposure, assessed through pharmacokinetic analysis, was associated with greater toxicity. No responses were seen. MET phosphorylation was feasible in CTC, but no changes were seen with therapy.Conclusions: The combination of topotecan and oral tivantinib was not tolerable in this patient population. [ABSTRACT FROM AUTHOR]

Background: The California Cancer Consortium completed a phase I trial of E7389 (eribulin mesylate), an analog of the marine natural product halichondrin B. This trial was to determine the pharmacodynamics, pharmacokinetics, and MTD of E7389 administered by bolus injection weekly for 3 weeks out of four.Methods: This trial included a rapid titration design. Real-time pharmacokinetics were utilized to guide dose escalation. Initially, single-patient cohorts were enrolled with intra- and inter-patient dose doubling. The second phase was a standard 3 + 3 dose escalation schedule. At the MTD, a cohort of patients was enrolled for target validation studies (separate manuscript). The starting dose was 0.125 mg/m(2), and doses were doubled within and between patients in the first phase. Blood and urine sampling for E7389 pharmacokinetics was performed on doses 1 and 3 of cycle 1. Levels were determined using a LC/MS/MS assay.Results: Forty patients were entered. Thirty-eight were evaluable for toxicity and 35 for response. The rapid escalation ended with a grade 3 elevation of alkaline phosphatase at 0.5 mg/m(2)/week. The second phase ended at 2.0 mg/m(2)/week with dose-limiting toxicities of grades 3 and 4 febrile neutropenia. Other toxicities included hypoglycemia, hypophosphatemia, and fatigue. The MTD was 1.4 mg/m(2)/week. Responses included four partial responses (lung cancer [2], urothelial [1], and melanoma [1]).Conclusions: E7389 was well tolerated in this trial with the major toxicity being myelosuppression. PD shows that E7389 induces significant morphologic changes (bundle formation) in the microtubules of peripheral blood mononuclear cells and tumor cells in vivo. The data suggest that lower intra-tumoral levels of β-tubulin III or higher intra-tumoral levels of MAP4 may correlate with response to E7389, while lower intra-tumoral levels of stathmin may be associated with progression. PK data reveal that E7389 exhibits a tri-exponential elimination from the plasma of patients receiving a rapid i.v. infusion. At sub-toxic doses, plasma concentrations of E7389 are maintained well above the levels required for activity in vitro for >72 h. [ABSTRACT FROM AUTHOR]

Purpose: Pyrrole-imidazole (Py-Im) polyamides are programmable, sequence-specific DNA minor groove-binding ligands. Previous work in cell culture has shown that various polyamides can be used to modulate the transcriptional programs of oncogenic transcription factors. In this study, two hairpin polyamides with demonstrated activity against androgen receptor signaling in cell culture were administered to mice to characterize their pharmacokinetic properties.Methods: Py-Im polyamides were administered intravenously by tail vein injection. Plasma, urine, and fecal samples were collected over a 24-h period. Liver, kidney, and lung samples were collected postmortem. Concentrations of the administered polyamide in the plasma, excretion, and tissue samples were measured using LC/MS/MS. The biodistribution data were analyzed by both non-compartmental and compartmental pharmacokinetic models. Animal toxicity experiments were also performed by monitoring weight loss after a single subcutaneous (SC) injection of either polyamide.Results: The biodistribution profiles of both compounds exhibited rapid localization to the liver, kidneys, and lungs upon injection. Plasma distribution of the two compounds showed distinct differences in the rate of clearance, the volume of distribution, and the AUCs. These two compounds also have markedly different toxicities after SC injection in mice.Conclusions: The variations in pharmacokinetics and toxicity in vivo stem from a minor chemical modification that is also correlated with differing potency in cell culture. The results obtained in this study could provide a structural basis for further improvement of polyamide activity both in cell culture and in animal models. [ABSTRACT FROM AUTHOR]

GTI-2040 is a 20-mer antisense oligonucleotide targeting the mRNA of ribonucleotide reductase M2. It was combined with oxaliplatin and capecitabine in a phase I trial in patients with advance solid tumors based on previous studies demonstrating potentiation of chemotherapy with ribonucleotide reductase inhibitors. Patients at least 18 years of age with advanced incurable solid tumors and normal organ function as well as a Karnofsky performance status of ≥60% were eligible. One prior chemotherapy regimen for advanced disease or relapse within 12 months of adjuvant chemotherapy was required. Patients could have received prior fluoropyrimidines, including capecitabine, but not oxaliplatin. Treatment cycles were 21 days. In each cycle, GTI-2040 was given as a continuous intravenous infusion over 14 days, oxaliplatin as a 2-h intravenous infusion on day 1, and capecitabine orally twice a day for 14 days. In cycle 1 only, oxaliplatin and capecitabine were started on day 2 to allow ribonucleotide reductase mRNA levels to be measured with and without oxaliplatin and capecitabine. Doses were escalated in cohorts of three patients using a standard 3 + 3 design until the maximum tolerated dose was established, defined as no more than one first-cycle dose-limiting toxicity among six patients treated at a given dose level. The maximum tolerated dose was estimated to be the combination of GTI-2040 3 mg/kg per day for 14 days, capecitabine 600 mg/m2 twice daily for 14 days, and oxaliplatin 100 mg/m2 every 21 days. Dose-limiting toxicities were hematologic. GTI-2040 pharmacokinetics, obtained at steady-state on days 7 and 14, showed the high inter-patient variability previously reported. Two of six patients had stable disease at the maximum tolerated dose and one patient, with heavily pre-treated non-small cell lung cancer, had a partial response at a higher dose level. In samples from a limited number of patients, there was no clear decrease in ribonucleotide reductase expression in peripheral blood mononuclear cells during treatment. A combination of GTI-2040, capecitabine and oxaliplatin is feasible in patients with advanced solid tumors. [ABSTRACT FROM AUTHOR]

Purpose: Although the DNA methyltransferase inhibitor 5-fluoro-2'-deoxycytidine (FdCyd), is being evaluated clinically, it must be combined with the cytidine deaminase inhibitor tetrahydrouridine (THU) to prevent rapid metabolism of FdCyd to the pharmacologically active, yet unwanted, metabolites 5-fluoro-2'-deoxyuridine (FdUrd), 5-fluorouracil (FU), and 5-fluorouridine (FUrd). We assessed plasma concentrations of FdCyd and metabolites in patients receiving FdCyd and THU.Methods: We validated an LC-MS/MS assay, developed for a preclinical study, to quantitate FdCyd and metabolites in human plasma. Patients were treated with five daily, 3-h infusions of FdCyd at doses of 5-80 mg/m(2) with 350 mg/m(2) THU. Plasma was obtained during, and before the end of infusions on days 1 and 5.Results: The lower limits of quantitation for FU, FdUrd, FUrd, FC and FdCyd were 1, 1.5, 10, 3, and 10 ng/ml, respectively. Plasma FdCyd increased with dose, from 19-96 ng/ml at 5 mg/m(2) to 1,600-1,728 ng/ml at 80 mg/m(2). FdUrd was undetectable in patients treated with FdCyd doses <20 mg/m(2), and increased from 2.3 ng/ml at 20 mg/m(2) to 3.5-5.7 ng/ml at 80 mg/m(2). FU increased from 1.2-5.5 ng/ml at 5 mg/m(2) to 6.0-12 ng/ml at 80 mg/m(2).Conclusions: By co-administering FdCyd with THU, FdCyd plasma concentrations were achieved that are known to inhibit DNA methylation in vitro. The accompanying plasma FU and FdUrd concentrations are <10% those observed after therapeutic infusions of FU or FdUrd, while FdCyd levels are well above those required to inhibit methylation in vitro. Therefore, inhibition of DNA methylation with FdCyd and THU appears feasible. [ABSTRACT FROM AUTHOR]

Purpose. To determine the response rate to 26-h continuous infusion cyclosporine A (CSA) combined with a fixed dose level of carboplatin (CBDCA) in patients with recurrent ovarian cancer, and to determine the effect of CSA on the pharmacokinetics of CBDCA. Experimental design. To examine the effect of duration of CSA exposure on reversal of CBDCA resistance, clonogenic assays were performed in vitro in platinum-resistant A2780 cells. CBDCA (AUC 4) with CSA repeated every 3 weeks was then administered to patients on this phase II study. Pharmacokinetics of CSA and CBDCA were determined in a subset of patients. Results. Preincubation of platinum-resistant A2780 cells with CSA reversed CBDCA resistance in a concentration-dependent and time-dependent manner. A group of 23 patients received 58 courses of CBDCA/CSA therapy. One partial response was observed. Eight patients achieved disease stabilization. Toxicity was similar to that observed in our previous phase I study and consisted of myelosuppression, nausea, vomiting, and headache. The mean±SD end-of-infusion CSA level (HPLC assay) was 1253±400 μg/ml. The pharmacokinetic studies suggest that CSA does not increase CBDCA AUC. Conclusions. Steady-state levels of >1 μg/ml CSA (HPLC assay) are achievable in vivo. Modest partial reversal of platinum resistance (in one patient with an objective response and in eight patients with stable disease noted) is achievable in vivo in patients pretreated with CSA. This phenomenon is not explained by alterations in CBDCA pharmacokinetics. [ABSTRACT FROM AUTHOR]

Purpose. Dexrazoxane administration prior to short infusion doxorubicin prevents anthracycline-related heart damage. Since delivery of doxorubicin by 96-h continuous intravenous infusion also reduces cardiac injury, we studied delivering dexrazoxane and doxorubicin concomitantly by prolonged intravenous infusion. Methods. Patients with advanced malignancies received tandem cycles of concurrent 96-h infusions of dexrazoxane 500 mg/m2 and doxorubicin 165 mg/m2, and 24 h after completion of chemotherapy, granulocyte-colony stimulating factor (5 μg/kg) and oral levofloxacin (500 mg) were administered daily until the white blood cell count reached 10,000 μl-1. Plasma samples were analyzed for dexrazoxane and doxorubicin concentrations. Results. Ten patients were enrolled; eight patients had measurable disease. Two partial responses were observed in patients with soft-tissue sarcoma. The median number of days of granulocytopenia (<500 μl-1) was nine and of platelet count <20,000 μl-1 was seven. Six patients received a single cycle because of progression (one), stable disease (four), or reversible, asymptomatic 10% decrease in cardiac ejection fraction (two). Principal grade 3/4 toxicities included hypotension (two), anorexia (four), stomatitis (four), typhlitis (two), and febrile neutropenia (seven), with documented infection (three). One death from neutropenic sepsis occurred. Dexrazoxane levels ranged from 1270 to 2800 nM, and doxorubicin levels ranged from 59.1 to 106.9 nM. Conclusions. These results suggest that tandem cycles of concurrent 96-h infusions of dexrazoxane and high-dose doxorubicin can be administered with minimal cardiac toxicity, and have activity in patients with recurrent sarcomas. However, significant non-cardiac toxicities indicate that the cardiac sparing potential of this approach would be maximized at lower dose levels of doxorubicin. [ABSTRACT FROM AUTHOR]

Cytochrome P450 3A4 is an important mediator of drug catabolism that can be regulated by the steroid and xenobiotic receptor (SXR). We show here that SXR also regulates drug efflux by activating expression of the gene MDR1, which encodes the protein P-glycoprotein (ABCB1). Paclitaxel (Taxol), a commonly used chemotherapeutic agent, activated SXR and enhanced P-glycoprotein?mediated drug clearance. In contrast, docetaxel (Taxotere), a closely related antineoplastic agent, did not activate SXR and displayed superior pharmacokinetic properties. Docetaxel's silent properties reflect its inability to displace transcriptional corepressors from SXR. We also found that ET-743, a potent antineoplastic agent, suppressed MDR1 transcription by acting as an inhibitor of SXR. These findings demonstrate how the molecular activities of SXR can be manipulated to control drug clearance. [ABSTRACT FROM AUTHOR]

Purpose: In recognition of the variety of available chemotherapeutic modulating agents and their potential to enhance the efficacy of platinum-based therapy, we embarked upon a phase I study to investigate the feasibility of combining fixed doses of carboplatinum (CBDCA) and etoposide (VP-16) with 24-h concurrent infusions of dipyridamole (DP), prochlorperazine (PCZ) and cyclosporine A (CSA) administered in escalating doses. Methods: Patients received intravenous VP-16 (200 mg/m2) and CBDCA (300 mg/m2), each over 30 min, starting at hour 6 of the modulator infusions. Resistance modulators were escalated sequentially to determine their respective maximally tolerated doses (MTDs). The pharmacokinetics (PK) of VP-16, CBDCA, and the three drug resistance (DR) modifiers were studied in eight patients. Results: A total of 59 patients were entered on study. The MTD was established at DP 5 mg/kg per day, PCZ 24 mg/h, and CSA 9.5 mg/kg per day. Dose-limiting toxicities included hypotension and severe sedation, presumably related to PCZ. No objective responses were seen. PK studies were performed when PCZ and DP doses were 24 mg/h and 3.3 mg/kg, and the CSA dose was either 8.5 mg/kg (five patients) or 9.5 mg/kg (three patients). The median clearance of VP-16 was 0.96 l/h per m2 (range 0.8–1.5 l/h per m2), which is lower than for VP-16 alone and similar to previously reported effects of CSA on VP-16 elimination. The median measured CBDCA AUC was 3.0 mg/ml · min (range 2.4–4.8 mg/ml · min). CBDCA AUC predicted by the Calvert formula using measured creatinine clearance underestimated the actual AUC in seven of the eight patients, in one case by as much as twofold. The median end of infusion PCZ and total DP plasma concentrations were 1.2 μM (range 0.5–2.2 μM) and 4.4 μM (range 1.3–5.9 μM), respectively, consistent with in vitro resistance modulatory levels. However, free DP was only 0.02 μM (range 0.004–0.04 μM). The median CSA level at 24 h of 1450 μg/l (range 1075–1640 μg/l) is in agreement with concentrations required for partial DR reversal in vitro, although it is much lower than levels achieved in our previous phase I study of CBDCA + CSA alone using similar doses of CSA. The CSA dose on the current trial was escalated beyond the MTD for the previous phase I study, suggesting that there may be an interaction between CSA and one of the other modulators. Conclusion: These results demonstrate that in vitro DR- reversing levels of two of the three agents used in this study can be achieved in vivo, and that this combination of DR modulators has significant effects on the pharmacokinetics of VP-16. [ABSTRACT FROM AUTHOR]