Feasibility of adding everolimus to carboplatin and paclitaxel, with or without bevacizumab, for treatment-naive, advanced non-small cell lung cancer.

INTRODUCTION: One standard of care for advanced non-small cell lung cancer (NSCLC) is paclitaxel plus carboplatin ± bevacizumab. This two-step phase I study evaluated the feasibility of adding everolimus to paclitaxel plus carboplatin ± bevacizumab for advanced NSCLC. METHODS: Adults with advanced NSCLC naive to systemic therapy were enrolled. A Bayesian dose-escalation model was used to identify feasible daily or weekly everolimus doses given with paclitaxel (200 mg/m(2) q21 days) and carboplatin (AUC 6 mg/mL/min q21 days) (step 1) and paclitaxel (200 mg/m(2) q21 days), carboplatin (AUC 6 mg/mL/min q21 days), and bevacizumab (15 mg/kg q21 days) (step 2). Primary endpoint was end-of-cycle 1 dose-limiting toxicity (DLT) rate. Secondary endpoints included safety; relative dose intensities of paclitaxel, carboplatin, and bevacizumab; pharmacokinetics; and tumor response. RESULTS: Fifty-two patients were enrolled and received everolimus 5 mg/day plus carboplatin and paclitaxel (step 1 daily; n = 13); everolimus 30 mg/week plus carboplatin and paclitaxel (step 1 weekly; n = 13); everolimus 5 mg/day plus carboplatin, paclitaxel, and bevacizumab (step 2 daily; n = 13); or everolimus 30 mg/week plus carboplatin, paclitaxel, and bevacizumab (step 2 weekly; n = 13). End-of-cycle 1 DLT rate was 16.7 % (step 1 daily), 30.8 % (step 1 weekly), 30.0 % (step 2 daily), and 16.7 % (step 2 weekly). Cycle 1 DLTs were grade 3 neutropenia, anal abscess, diarrhea, and thrombocytopenia and grade 4 myalgia, cellulitis, neutropenia, febrile neutropenia, pulmonary embolism, and thrombocytopenia. The most common adverse events were neutropenia, fatigue, anemia, and thrombocytopenia. One patient (step 2 daily) experienced complete response, 10 patients partial response. CONCLUSIONS: The feasible everolimus doses given with carboplatin and paclitaxel ± bevacizumab were 5 mg/day and 30 mg/week. Neither schedule was very well tolerated in this unselected NSCLC population.

An ELISA for quantification of T84.66, a monoclonal anti-CEA antibody, in mouse plasma.

T84.66 is a monoclonal antibody with high affinity and specificity for tumor-associated carcinoembryonic antigen (CEA). In this work, we have developed an enzyme linked immunosorbent assay to determine T84.66 concentrations in mouse plasma. The assay was validated with respect to precision and accuracy by evaluating the recovery of T84.66 from mouse plasma. The working range of the assay is 25-200 ng/mL, and the limit of quantification is 2.5 microg/mL. Intra-assay recoveries ranged from 90.6 to 97.4%, and intra-assay precision reported as the percent coefficient of variation (CV%), ranged from 4.58 to 12.6%. Inter-assay recoveries were between 92.6 to 98.1% and the CV% ranged from 4.9-6.5%. The assay was tested for possible interference from soluble CEA. Soluble CEA, at concentrations up to 5 ng/mL, did not influence the recovery of T84.66. The assay was applied to study the pharmacokinetics of T84.66 in athymic Fox(nu) mice.

Development and validation of an enzyme linked immunosorbent assay for the quantification of carcinoembryonic antigen in mouse plasma.

Carcinoembryonic antigen (CEA) is a tumor associated antigen that is over-expressed in colorectal cancer and several other cancers of the gastrointestinal system. An enzyme linked immunosorbent assay was developed to determine CEA concentrations in mouse plasma. The assay was validated over the standard curve range of 1-20 ng/mL. The intra-assay recoveries ranged from 93-104% with associated percent coefficients of variation (CV%) ranging between 2.5-12.8%. The inter-assay recoveries were in the range of 98.4-105% and their CV% values were between 4.77-10.1%. The assay was used to detect the presence of circulating CEA in the LS174T adenocarcinoma xenograft model and to study the pharmacokinetics of recombinant CEA in athymic mice.

Relationship between everolimus exposure and safety and efficacy: meta-analysis of clinical trials in oncology.

BACKGROUND: In patients with solid tumours, daily everolimus dosing demonstrated dose proportionality and linear pharmacokinetics. A meta-analysis was conducted to characterise the relationship between everolimus Cmin and efficacy and safety and the effect of CYP3A4 and P-glycoprotein (PgP) substrate/inhibitor/inducer coadministration on everolimus trough concentration (Cmin). METHODS: Individual patient data from five phase 2/3 studies, in which steady state, predose pharmacokinetic samples were taken from patients with solid tumours administered everolimus 10mg/day, were pooled. FINDINGS: Efficacy and safety were evaluable for 945 and 938 patients, respectively. A 2-fold increase in everolimus Cmin increased the likelihood of tumour size reduction (odds ratio 1.40, 95% confidence interval (CI) 1.23-1.60), was associated with a trend for reduced risk of progression-free survival events (risk ratio [RR] 0.90, 95% CI 0.69-1.18) and increased the risk of grade ⩾3 pulmonary (RR 1.93, 95% CI 1.12-3.34), stomatitis (RR 1.49, 95% CI 1.05-2.10) and metabolic (RR 1.30, 95% CI 1.02-1.65) events. Coadministering everolimus with strong CYP3A4 and PgP inhibitors increased everolimus Cmin by 10% and 20%, respectively; coadministration with CYP3A4 inducers reduced Cmin by 7%. INTERPRETATION: A 2-fold increase in everolimus Cmin was associated with improved tumour size reduction and increased risk of high-grade pulmonary, metabolic and stomatitis events. FUNDING: Novartis Pharmaceuticals Corporation.

Target mediated disposition of T84.66, a monoclonal anti-CEA antibody: application in the detection of colorectal cancer xenografts.

Carcinoembryonic antigen (CEA) is a glycosylated cell surface antigen known to be highly overexpressed in several adenocarcinomas, including colorectal cancer, while demonstrating limited expression in normal tissues. Prior work has shown that the plasma clearance of T84.66, a monoclonal anti-CEA antibody, is enhanced by several-fold in a CEA-expressing xenograft mouse model, suggesting the presence of a target mediated elimination pathway. The purpose of this study is to investigate the influence of tumor volume on the plasma clearance of T84.66, and test the hypothesis that the plasma pharmacokinetics of T84.66 may be used as a sensitive and selective test for the diagnosis of CEA-positive tumors. T84.66 plasma pharmacokinetics were studied following intravenous (i.v.) administration of a 1 mg/kg dose in animals without tumor and mice bearing low (20-75 mm(3)), medium (400-570 mm(3)), and high volume (800-1,200 mm(3)) LS174T xenografts. Based on comparison of the disposition of T84.66 in non-tumor bearing mice and mice bearing low-volume tumors, it was predicted that a single plasma concentration of T84.66, obtained seven days after dosing, would provide a sensitive and selective means of determining the presence of tumor in mice. A blinded follow-up study was conducted using athymic mice with or without intraperitoneal LS174T xenografts. 1 mg/kg of (125)I-T84.66 was administered i.v., and plasma samples were collected on day 7. Comparison of the observed concentration of (125)I-T84.66 to the pre-determined threshold value (7.63 nM) enabled identification of tumor bearing mice with a sensitivity of 93.3% and specificity of 100%.

Physiologically based pharmacokinetic model for T84.66: a monoclonal anti-CEA antibody.

Antibodies directed against tumor associated antigens are being increasingly used for detection and treatment of cancers; however, there is an incomplete understanding of the physiological determinants of antibody pharmacokinetics and tumor distribution. The purpose of this study is to (a) compare the plasma pharmacokinetics of T84.66, a monoclonal anti-CEA antibody directed against tumor associated carcinoembryonic antigen (CEA), in control and CEA expressing LS174T xenograft bearing mice, and (b) to develop a physiologically based pharmacokinetic (PBPK) model capable of integrating the influence of CEA and the IgG salvage receptor, FcRn, on T84.66 disposition. T84.66 pharmacokinetics were studied following i.v. administration (1, 10, 25 mg/kg) in control and xenograft bearing mice. In control mice, no significant differences in clearance were observed across the dose range studied. In mice bearing xenograft tumors, clearance was increased by four- to sevenfold, suggesting the presence of a "target mediated" elimination pathway. T84.66 plasma disposition was characterized with a PBPK model, and the model was applied to successfully predict antibody concentrations in tumor tissue. The PBPK model will be used to assist in the development of antibody-based targeting strategies for CEA-positive tumors.

Sensitive high performance liquid chromatographic assay for assessment of doxorubicin pharmacokinetics in mouse plasma and tissues.

A sensitive high performance liquid chromatography method (HPLC) has been developed for the quantification of doxorubicin in mouse plasma and tissues. Samples of serum or tissue homogenates, 20 microl, were analyzed following a single step protein precipitation using perchloric acid (35%, v/v). Doxorubicin was separated from the internal standard, daunorubicin, on a Zorbax 300SB C(18) column at 35 degrees C. Mobile phase was comprised of acetonitrile and water (25:75) containing 0.1% triethylamine, and was adjusted to pH 3 with phosphoric acid. Peaks eluting from the column were detected with a fluorescence detector with excitation and emission wavelengths of 480 and 560 nm, respectively. Standard curves were linear in the range 5-1000 ng/ml, and correlation coefficients were typically greater than 0.999. Intra-assay recoveries ranged from 94.7 to 99.9%, and inter-assay recoveries were in the range of 95.2-101%. The associated coefficient of variation (CV) was less than 10% in all cases. The method was successfully applied to investigate doxorubicin plasma pharmacokinetics and tissue distribution in athymic Fox(nu) mice.