Contaminants of emerging concern: Silylation procedures, evaluation of the stability of silyl derivatives and associated measurement uncertainty

Analyte range of gas chromatography-mass spectrometry (GC-MS), widely used in environmental analysis, can be significantly broadened by derivatization. Silyl derivatives have improved volatility and thermal stability, chromatographic and mass spectrometric behaviors, and thus detection, structural elucidation and quantification. However, silylation use is often hindered by the stability of generated derivatives and the need to optimize silylation conditions. In this study, we optimized the derivatization conditions for 70 selected contaminants of emerging concern (CEC) using chemometrics approaches. N-methyl-N-(trimethylsilyl) trifluoroacetamide (MSTFA), N, O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) and BSTFA + 1 % trimethylchlorosilane (TMCS) were investigated, among which the latter gave the best yield. CEC were grouped in three derivatization protocols: 60 °C/45 min, 70 °C/90 min, and 70 °C/45 min. The short- and long-term stability of the CEC-trimethylsilyl (TMS) derivatives, i.e. for 28 days and up to 20 weeks were examined in a solvent and artificial wastewater (AWW) extract at 25 °C, 4 °C and - 18 °C, and during repeated five freeze-thaw (F/T) cycles, at two concentration levels: 100 μg/L and 1000 μg/L. Except for TMS derivatives of shikimic acid (SHA), quinic acid (QA) and sulfanilamide (SFA), the remaining derivatized compounds were stable in solvent (EtAc) for 28 days. In AWW extract, TMS derivatives of citric acid (CA), 17β-estradiol (E2), estriol (E3) and 17α-ethinyl estradiol (EE2) were unstable at 25 °C and 4 °C. Within up to 20 weeks, only the TMS derivatives of CA, meso-erythritol (ERY) and bisphenol BP (BPBP) were unstable. The most significant hydrolytic breakdown was observed during repeated F/T cycles. After three cycles, ≤ 20 % of the initial concentration of six and nine CEC-TMS derivatives had degraded in solvent and AWW extracts, respectively. According to the deep statistical comparison (DSC) approach, the most prominent degradation was observed for TMS derivatives of E2, CA, 9-hydroxyfluorene (9-HF), estrone (E1) and trans-3'-hydroxycotinine (T3HC) in solvent; E2, CA, 9-HF, E3 and E1 in AWW extracts and ERY, E2, CA, 9-HF and E1 in both matrices. Finally, the sample concentration of CEC accounted for most of the measurement uncertainty (MU). Based on our findings, we recommend the derivatized samples to be stored at -18 °C for up to 20 weeks to ensure the stability of their TMS derivatives. Sample freezing and thawing of not more than twice is allowed to maintain ≥80 % of the initial CEC-TMS concentration.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Performance of the HOOS-12 and KOOS-12 instruments for evaluating outcomes from joint replacement surgery

OBJECTIVE

To evaluate the psychometric properties of the 12-item Hip disability and Osteoarthritis Outcome Score (HOOS-12) and Knee injury and Osteoarthritis Outcome Score (KOOS-12) for use in evaluating outcomes after joint replacement for osteoarthritis.

DESIGN

Patient-reported outcomes data collected by the Australian Orthopaedic Association National Joint Replacement Registry were used for this analysis. HOOS-12 and KOOS-12 domain (pain, function, quality of life) and summary impact data were available. The Oxford Hip Score (OHS), Oxford Knee Score (OKS) and EQ-5D-5L were used as comparators. Instruments were administered pre-operatively and at 6 months post-operatively. Internal consistency reliability, floor and ceiling effects, convergent validity, known groups validity, and responsiveness were evaluated using standard psychometric techniques.

RESULTS

Baseline HOOS-12 and KOOS-12 data were available for 3,023 patients undergoing primary total hip replacement and 4,010 patients undergoing primary total knee replacement. At baseline, high internal consistency was demonstrated for all domains and summary scores (Cronbach's alpha: HOOS-12 = 0.81-0.93; KOOS-12 = 0.82-0.92). Post-operative ceiling effects (>15% of patients scoring the best possible score) were identified for the HOOS-12 pain (46%), function (39%) and quality of life domains (26%) and summary score (17%), and for the KOOS-12 pain (21%) and function domains (18%). The HOOS-12 and KOOS-12 could differentiate between two known groups (lowest/highest OHS or OKS quartiles post-operatively; p < 0.001) and were highly responsive to change (effect sizes for HOOS-12: 2.20-2.83; KOOS-12: 1.82-2.35).

CONCLUSION

The HOOS-12 and KOOS-12 have good psychometric properties for capturing joint replacement outcomes including excellent responsiveness, although ceiling effects may limit monitoring of post-operative improvement.

Evaluation of an x-ray CT polymer gel dosimetry system in the measurement of deformed dose

This study is an evaluation of the use of a N-isopropylacrylamide (NIPAM)-based x-ray CT polymer gel dosimetry (PGD) system in the measurement of deformed dose. This work also compares dose that is measured by the gel dosimetry system to dose calculated by a novel deformable dose accumulation algorithm, defDOSXYZnrc, that uses direct voxel tracking. Deformable gels were first irradiated using a single 3.5 × 5 cm² open field and the static dose was compared to defDOSXYZnrc as a control measurement. Gel measurement was found to be in excellent agreement with defDOSXYZnrc in the static case with gamma passing rates of 94.5% using a 3%/3 mm criterion and 93.3% using a 3%/2 mm criterion. Following the static measurements, a deformable gel was irradiated with the same single field under an external compression of 25 mm and then released from this compression for dosimetric read out. The measured deformed dose was then compared to deformed dose calculated by defDOSXYZnrc based on deformation vectors produced by the Velocity AI deformable image registration (DIR) algorithm. In the deformed dose distribution there were differences in the measured and calculated field position of up to 0.8 mm and differences in the measured in calculated field size of up to 11.9 mm. Gamma pass rates were 60.0% using a 3%/3 mm criterion and 56.8% using a 3%/2 mm criterion for the deforming measurements representing a decrease in agreement compared to the control measurements. Further analysis showed that passing rates increased to 86.5% using a 3%/3 mm criterion and 70.5% using a 3%/2 mm criterion in voxels within 5 mm of fiducial markers used to guide the deformable image registration. This work represents the first measurement of deformed dose using x-ray CT polymer gel dosimetry. Overall these results highlight some of the challenges in the calculation and measurement of deforming dose and provide insight into possible strategies for improvement.

Introduction of a deformable x-ray CT polymer gel dosimetry system

This study introduces the first 3D deformable dosimetry system based on x-ray computed tomography (CT) polymer gel dosimetry and establishes the setup reproducibility, deformation characteristics and dose response of the system. A N-isopropylacrylamide (NIPAM)-based gel formulation optimized for x-ray CT gel dosimetry was used, with a latex balloon serving as the deformable container and low-density polyethylene and polyvinyl alcohol providing additional oxygen barrier. Deformable gels were irradiated with a 6 MV calibration pattern to determine dosimetric response and a dosimetrically uniform plan to determine the spatial uniformity of the response. Wax beads were added to each gel as fiducial markers to track the deformation and setup of the gel dosimeters. From positions of the beads on CT images the setup reproducibility and the limits and reproducibility of gel deformation were determined. Comparison of gel measurements with Monte Carlo dose calculations found excellent dosimetric accuracy, comparable to that of an established non-deformable dosimetry system, with a mean dose discrepancy of 1.5% in the low-dose gradient region and a gamma pass rate of 97.9% using a 3%/3 mm criterion. The deformable dosimeter also showed good overall spatial dose uniformity throughout the dosimeter with some discrepancies within 20 mm of the edge of the container. Tracking of the beads within the dosimeter found that sub-millimetre setup accuracy is achievable with this system. The dosimeter was able to deform and relax when externally compressed by up to 30 mm without sustaining any permanent damage. Internal deformations in 3D produced average marker movements of up to 12 mm along the direction of compression. These deformations were also shown to be reproducible over 100 consecutive deformations. This work has established several important characteristics of a new deformable dosimetry system which shows promise for future clinical applications, including the validation of deformable dose accumulation algorithms.

Erratum: Epigenetic silencing of miR-34a in human prostate cancer cells and tumor tissue specimens can be reversed by BR-DIM treatment

Androgen Receptor (AR) signaling is critically important during the development and progression of prostate cancer (PCa). The AR signaling is also important in the development of castrate resistant prostate cancer (CRPC) where AR is functional even after androgen deprivation therapy (ADT); however, little is known regarding the transcriptional and functional regulation of AR in PCa. Moreover, treatment options for primary PCa for preventing the occurrence of CRPC is limited; therefore, novel strategy for direct inactivation of AR is urgently needed. In this study, we found loss of miR-34a, which targets AR, in PCa tissue specimens, especially in patients with higher Gleason grade tumors, consistent with increased expression of AR. Forced over-expression of miR-34a in PCa cell lines led to decreased expression of AR and prostate specific antigen (PSA) as well as the expression of Notch-1, another important target of miR-34a. Most importantly, BR-DIM intervention in PCa patients prior to radical prostatectomy showed reexpression of miR-34a, which was consistent with decreased expression of AR, PSA and Notch-1 in PCa tissue specimens. Moreover, BR-DIM intervention led to nuclear exclusion both in PCa cell lines and in tumor tissues. PCa cells treated with BR-DIM and 5-aza-dC resulted in the demethylation of miR-34a promoter concomitant with inhibition of AR and PSA expression in LNCaP and C4-2B cells. These results suggest, for the first time, epigenetic silencing of miR-34a in PCa, which could be reversed by BR-DIM treatment and, thus BR-DIM could be useful for the inactivation of AR in the treatment of PCa.[This corrects the article on p. 14 in vol. 4.].

SU-E-T-637: 4D-VMAT Vs. Gated VMAT in Lung Cancer SBRT

PURPOSE

To assess plan quality and treatment efficiency of 4D-VMAT and gated-VMAT in the treatment of non-small cell lung cancer using SBRT.

METHODS

Treatment planning software was developed in Matlab to simulate both 4D-VMAT and gated-VMAT on patients with stage I lung cancer and at least 1 cm of tumour motion. Gated-VMAT delivers radiation to the tumour during only a portion of the respiratory cycle and hence requires frequent start and stop motions of the gantry. In the 4D-VMAT algorithm, target and organ motion from the entire respiratory cycle is incorporated during optimization. Gantry moves continuously but delivery of each MLC aperture is synchronized to specific phases of target motion. All 4D-CT scan consisted of 10 phases and were acquired with the patients breathing freely. The SBRT fractionation scheme was 48 Gy in 4 fractions with at least 95% of the PTV receiving 100% of the prescription dose. For gated-VMAT, the PTV was derived from the ITV of the relevant respiratory phases plus a 5mm margin. In the 4D VMAT algorithm, the GTV was defined on a single phase and the PTV created with a 5mm margin. PTVs for the other respiratory phases were determined through 4D-image registration and deformation using a bspline transformation model. For both treatment deliveries, dose was accumulated on the maximum exhale phase and DVHs generated.

RESULTS

Findings show gated-VMAT and 4D-VMAT deliveries resulted in maximum doses to most OARs far below SBRT protocol constraints. The 4D-VMAT beam on time is on average 8 min. Gated-VMAT will have similar beam on time but treatment time can more than double after accounting for 25 to 35 beam interruptions per arc.

CONCLUSIONS

Gated-VMAT and 4D-VMAT were able to produce dosimetrically acceptable lung SBRT plans. The advantage of 4D-VMAT is the greater efficiency in treatment delivery.

Monte Carlo modeling and simulations of the High Definition (HD120) micro MLC and validation against measurements for a 6 MV beam

PURPOSE

The most recent Varian(®) micro multileaf collimator (MLC), the High Definition (HD120) MLC, was modeled using the BEAMNRC Monte Carlo code. This model was incorporated into a Varian medical linear accelerator, for a 6 MV beam, in static and dynamic mode. The model was validated by comparing simulated profiles with measurements.

METHODS

The Varian(®) Trilogy(®) (2300C/D) accelerator model was accurately implemented using the state-of-the-art Monte Carlo simulation program BEAMNRC and validated against off-axis and depth dose profiles measured using ionization chambers, by adjusting the energy and the full width at half maximum (FWHM) of the initial electron beam. The HD120 MLC was modeled by developing a new BEAMNRC component module (CM), designated HDMLC, adapting the available DYNVMLC CM and incorporating the specific characteristics of this new micro MLC. The leaf dimensions were provided by the manufacturer. The geometry was visualized by tracing particles through the CM and recording their position when a leaf boundary is crossed. The leaf material density and abutting air gap between leaves were adjusted in order to obtain a good agreement between the simulated leakage profiles and EBT2 film measurements performed in a solid water phantom. To validate the HDMLC implementation, additional MLC static patterns were also simulated and compared to additional measurements. Furthermore, the ability to simulate dynamic MLC fields was implemented in the HDMLC CM. The simulation results of these fields were compared with EBT2 film measurements performed in a solid water phantom.

RESULTS

Overall, the discrepancies, with and without MLC, between the opened field simulations and the measurements using ionization chambers in a water phantom, for the off-axis profiles are below 2% and in depth-dose profiles are below 2% after the maximum dose depth and below 4% in the build-up region. On the conditions of these simulations, this tungsten-based MLC has a density of 18.7 g cm(- 3) and an overall leakage of about 1.1 ± 0.03%. The discrepancies between the film measured and simulated closed and blocked fields are below 2% and 8%, respectively. Other measurements were performed for alternated leaf patterns and the agreement is satisfactory (to within 4%). The dynamic mode for this MLC was implemented and the discrepancies between film measurements and simulations are within 4%.

CONCLUSIONS

The Varian(®) Trilogy(®) (2300 C/D) linear accelerator including the HD120 MLC was successfully modeled and simulated using the Monte Carlo BEAMNRC code by developing an independent CM, the HDMLC CM, either in static and dynamic modes.

Environmental occurrence, fate and transformation of benzodiazepines in water treatment

Benzodiazepine derivatives are prescribed in large quantities globally and are potentially new emerging environmental contaminants. Unfortunately, a dearth of data exists concerning occurrence, persistence and fate in the environment. This paper redresses this by reviewing existing literature, assessing the occurrence of selected benzodiazepine anxiolytics (diazepam, oxazepam and bromazepam) in wastewater influent and effluent and surface water from Slovenia, evaluating their removal during water treatment and identifying the transformation products formed during water treatment. Their occurrence was monitored in hospital effluent, river water and in wastewater treatment plant influent and effluent. The study reveals the presence of benzodiazepine derivatives in all samples with the highest amounts in hospital effluents: 111 ng L(-1), 158 ng L(-1) and 72 ng L(-1) for diazepam, bromazepam and oxazepam, respectively. Removal efficiencies with respect to biological treatment of diazepam were 16-18% (oxic), 18-32% (anoxic→oxic), 53-76% (oxic→anoxic) and 83% (oxic→anoxic→oxic→anoxic cascade bioreactors), while the removal oxazepam was 20-24% under anoxic conditions. Coupled biological and photochemical treatment followed by the adsorption to activated carbon resulted in a removal efficiency of 99.99%. Results reveal the recalcitrant nature of benzodiazepine derivatives and suggest that only combinational treatment is sufficient to remove them. In addition, eight novel diazepam and four novel oxazepam transformation products are reported.

Dosimetric consequences of tumour motion due to respiration for a scanned proton beam

A method for simulating spot-scanned delivery to a moving tumour was developed which uses patient-specific image and plan data. The magnitude of interplay effects was investigated for two patient cases under different fractionation and respiratory motion variation scenarios. The use of volumetric rescanning for motion mitigation was also investigated. For different beam arrangements, interplay effects lead to severely distorted dose distributions for a single fraction delivery. Baseline shift variations for single fraction delivery reduced the dose to the clinical target volume (CTV) by up to 14.1 Gy. Fractionated delivery significantly reduced interplay effects; however, local overdosage of 12.3% compared to the statically delivered dose remained for breathing period variations. Variations of the tumour baseline position and respiratory period were found to have the largest influence on target inhomogeneity; these effects were reduced with fractionation. Volumetric rescanning improved the dose homogeneity. For the CTV, underdosage was improved by up to 34% in the CTV and overdosage to the lung was reduced by 6%. Our results confirm that rescanning potentially increases the dose homogeneity; however, it might not sufficiently compensate motion-induced dose distortions. Other motion mitigation techniques may be required to additionally treat lung tumours with scanned proton beams.

Abstract P3-14-20: Phase 1 Dose-Escalation Study of the Investigational HER2/EGFR Inhibitor TAK-285 in Patients with Advanced Cancer

Background and Objectives: TAK-285 is a novel, orally active, dual HER2/EGFR inhibitor. Nonclinical data show that TAK-285 has high selectivity and specificity for binding to HER family kinases, and has demonstrated anti-tumor activity in a BT-474 mouse xenograft model of breast cancer. Nonclinical data also indicate that TAK-285 is not a substrate for the efflux transporters P-gp and BCRP and penetrates an intact blood-brain barrier in rats. This phase 1 dose-escalation study in patients with advanced cancer aimed to determine the safety and pharmacokinetic (PK) profile.

Methods: Adults had advanced histologically confirmed non-hematologic malignancies, life expectancy &gt;12 weeks, adequate bone marrow, liver and renal function, ECOG PS 0-2, and were refractory to other treatments. Oral TAK-285 was escalated from 50 to 500 mg QD or BID for 21 or 28 consecutive days of a 28-day cycle until disease progression or unacceptable toxicity was observed.

Results: At the data cut-off of 04/23/10, the dose-escalation portion was complete, and the RP2D expansion cohort is ongoing. Preliminary data from the dose-escalation cohorts are reported. 43 patients (median age 60 years [43-76]) were enrolled: 30% ≥65 years, 51% female, and 86% white. Dose levels were 50 mg QD (N=4), 50 mg BID (N=7), and 75 mg BID (N=6) on d 1-21; and 150 mg (N=6), 225 mg (N=4), 325 mg (N=3), 400 mg (N=6), and 500 mg (N=7) BID on d 1-28. Median duration of exposure across all cohorts was 52 days (3-267). Four patients experienced a DLT in Cycle 1: 1 patient (50 mg BID) had Grade 3 pancreatitis; 1 patient (150 mg BID) had Grade 3 chest pain and Grade 3 hypoxia; 1 patient (500 mg BID) had Grade 3 increased ALT; and 1 patient (500 mg BID) had Grade 3 diarrhoea and Grade 3 hypokalaemia. The MTD was 400 mg BID d 1-28. 30 patients (70%) discontinued TAK-285, primarily due to disease progression (n=19, 44%) or an AE (n=9, 21%). Most frequent AEs were fatigue (37%), diarrhoea (35%), nausea (26%), anorexia (21%), vomiting (16%), and elevated AST (16%). 58% of patients had a drug-related AE; the most frequent were diarrhoea (21%), fatigue (19%), and rash (includes rash, rash maculo-papular and rash macular; 12%). 35% of patients had a grade 3/4 AE; the most common were hypokalaemia (7%), ileus, abdominal pain, and hypoxia (5% each). Grade 3/4 AEs related to TAK-285 were the DLTs in Cycle 1 and Grade 4 rhabdomyolysis in 1 patient (400 mg BID, d 1-28) in Cycle 3. 42% of patients experienced a serious AE (SAE); the only SAE seen in &gt;1 patient was ileus (n=2). 4 (9%) patients had fatal AEs; none were considered related to TAK-285. Absorption was fast: plasma concentrations peaked 2-3 hours post-dose. Steady-state plasma exposures increased with dose in a greater than dose-proportional manner, with PK steady-state achieved by Day 8. Accumulation was noted with BID dosing (mean accumulation ratio, 2.4 at MTD); there was moderate fluctuation in plasma concentrations over the steady-state dosing interval (mean Cmax:Cmin ratio, 2.4 at MTD).

Conclusions: The MTD for TAK-285 was 400 mg BID d 1-28. The RP2D cohort is ongoing and includes CSF collection to assess the CNS distribution of TAK-285. Updated safety as well as efficacy data for the dose escalation cohorts will be presented.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P3-14-20.

Inter-laboratory exercise on steroid estrogens in aqueous samples

An inter-laboratory comparison exercise was organized among European laboratories, under the aegis of EU COST Action 636: "Xenobiotics in Urban Water Cycle". The objective was to evaluate the performance of testing laboratories determining "Endocrine Disrupting Compounds" (EDC) in various aqueous matrices. As the main task three steroid estrogens: 17alpha-ethinylestradiol, 17beta-estradiol and estrone were determined in four spiked aqueous matrices: tap water, river water and wastewater treatment plant influent and effluent using GC-MS and LC-MS/MS. Results were compared and discussed according to the analytical techniques applied, the accuracy and reproducibility of the analytical methods and the nature of the sample matrices. Overall, the results obtained in this inter-laboratory exercise reveal a high level of competence among the participating laboratories for the detection of steroid estrogens in water samples indicating that GC-MS as well as LC-MS/MS can equally be employed for the analysis of natural and synthetic hormones.

Second interlaboratory exercise on non-steroidal anti-inflammatory drug analysis in environmental aqueous samples

Several interlaboratory exercises were organised within the framework of European FP6 project NORMAN. Among others, non-steroidal anti-inflammatory drugs were investigated in different aqueous samples in two sequential ring studies. The aim of both studies was to evaluate the state-of-art in Europe and to determine possible sources of variation, while also attempting to diminish them. In the present paper we discuss the results of the 2nd Interlaboratory study, while the results of 1st round were presented before. The main scope of the 1st exercise organised within NORMAN project was to assess the laboratory proficiency regardless of the analytical method applied, to evaluate the stability of the target compounds during sample storage, and to define possible sources of variation during sample shipment, storage and analysis. In the 2nd round we primarily aimed to diminish these sources of variation by applying two predetermined analytical protocols based on liquid chromatography-mass spectrometry or gas chromatography-mass spectrometry. The two analytical protocols were compared in terms of their ability to determine individual analytes in matrices of different complexity, i.e. tap water, river water and wastewater. Furthermore, the 2nd exercise addressed also the filtration and compared the influence of different filter material categories on the analysis of non-steroidal anti-inflammatory drugs. Results presented herein evaluate laboratory performance using z-score, bias, proximity and Youden plots. Overall, the laboratory performances were found to be satisfactory for determining NSAIDs in aqueous samples. The two analytical protocols, LC-MS and GC-MS, are assessed according to their sensitivity and measurement uncertainty, where the GC-MS proved superior for the analysis of Ibuprofen, Ketoprofen and Naproxen in matrices with higher complexity. Finally, neither the filtration itself, nor the filter materials were shown to significantly affect the determination of NSAIDs.

Tremelimumab in combination with exemestane as novel immunotherapy for patients with advanced breast cancer

3034

Background: Tremelimumab (CP-675, 206) is a fully human IgG2 anti-CTLA4 monoclonal antibody (mAb) with single-agent antitumor activity presumed to be related to immune stimulation following blockade of CTLA4. Here, we conducted a phase I, open-label, dose-escalation trial of the combination of tremelimumab and exemestane in patients (pts) with advanced hormone receptor (or unknown receptor status if prior response with hormone therapy) breast cancer. Methods: Twenty-five pts with ER+ and/or PR+ breast cancer and 1 pt with unknown receptor status who had relapsed after treatment for advanced disease were enrolled. Pts received escalating doses of tremelimumab (3 to 10 mg/kg) delivered either every 28 days (Q28D) or every 90 days (Q90D) in combination with continuous exemestane (25 mg/day). Primary endpoints were assessment of safety and determination of recommended phase II dose. Tumor response evaluation per RECIST was a secondary endpoint. Results: Overall, 65 cycles of tremelimumab were administered in combination with exemestane. Pts received 3 mg/kg tremelimumab Q28D (n=6), 6 mg/kg tremelimumab Q28D (n=1), 6 mg/kg tremelimumab Q90D (n=13), or 10 mg/kg Q90D (n=6). No pharmacokinetic interaction between tremelimumab and exemestane was observed. Dose-limiting toxicities included transient serum transaminase elevation in cycle 1 (grade 3 in 1 pt) and diarrhea in cycle 1 (grade 3 in 3 pts, 1 of whom was hospitalized with steroid-refractory diarrhea and given anti-tumor necrosis factor-α mAb, infliximab) and cycle 2 (grade 3 in 1 pt). One pt developed grade 2 autoimmune thyroiditis requiring chronic hormone replacement. Other toxicities included constipation (n=6), fatigue (n=8), and rash (n=9). The MTD was 6 mg/kg Q90D. For pts receiving ≥2 cycles of therapy, best response was stable disease in 8 pts lasting 3 to 14 months (median 8 months); no pts had objective responses. Conclusions: MTD of tremelimumab in combination with exemestane is estimated at 6 mg/kg Q90D, which is lower than the single-agent dose of 15 mg/kg Q90D used in phase II and III trials in pts with melanoma or colorectal cancer. This may suggest that there is a biological interaction between tremelimumab and exemestane.

[Table: see text]

Safety and efficacy analysis of sunitinib (S), bevacizumab (B), and M-Tor inhibitors in metastatic renal cell cancer (mRCC) patients (pts) with renal insufficiency (RI)

5108

Background: S, T (temsirolimus) and E (everolimus) are primarily metabolized in the liver, while the metabolism of B is unclear. There are limited data on the clinical toxicity profile and efficacy of these agents in pts with RI. Methods: The primary objective was to assess the safety and efficacy of S, B, T and E in pts with RI. Medical records of pts with mRCC at Wayne State University, treated on S, B, T or E were reviewed. Pts with a calculated creatinine clearance (CrCl) of ≤ 60ml/min [chronic kidney disease stage 3 or higher per K/DOQI guidelines by the National Kidney Foundation] were deemed to have RI. Data on safety and efficacy of the therapy were collected and analyzed with respect to renal function. Results: 19 of 51 (37%) pts had RI. Pts with RI had a higher median rise in blood pressure (BP) with S and B than pts with normal renal function. Patients with RI had an increased incidence of rash and higher dose interruption rates with m-TOR inhibitors. No major differences in toxicities including cardiac, thyroid, renal, lipid profile abnormalities or hyperglycemia were observed. Similar efficacy was seen in all groups. Conclusions: More than a third of pts with mRCC receiving targeted therapy have RI, hence highlighting the importance of evaluating tolerability of therapies in pts with RI. Therapy with S, B and T/E is well tolerated and efficacy appears to be maintained. Closer monitoring for hypertension is needed in pts receiving S and B.

[Table: see text]

No significant financial relationships to disclose.

ECOG 8802: Phase II trial of doxorubicin (Dox) and gemcitabine (Gem) in metastatic renal cell carcinoma (RCC) with sarcomatoid features

5038

Background: Patients (pts) with RCC containing sarcomatoid features have poor prognoses.Cytokine therapy is ineffective, and experience with mTor inhibitors or multi-targeted tyrosine kinase inhibitors is early. We evaluated Dox/Gem in these pts with locally advanced or metastatic disease to confirm previous activity of this regimen in a single institution trial. Methods: Pts received Dox 50mg/m2 IV push and Gem 1500mg/m2 IV over 30 minutes every 2 weeks (with G-CSF 5 mcg/kg/d days 2 or 3 to 10 or pegfilgrastim 6 mg day 2) until disease progression or unacceptable toxicity. Dose reductions occurred for low granulocytes and or platelets, mucositis, cardiac toxicity, or other grade 3 - 4 toxicities. Dox was discontinued after a cumulative dose of 450 mg/m2 unless pt had normal cardiac function. The study targeted a promising response rate (RR) of 20% vs. 5%, with 90% power and 8% Type I error. A 2-stage design was used; >4 responses were needed for efficacy. Results: From February 2004 to April 2007, 39 pts with RCC of sarcomatoid (47%) or mixed histology (53%) containing sarcomatoid features were accrued by ECOG (n = 35), NCCTG (n = 2), and CALGB (n = 2). 1 pt withdrew before treatment. Pts were mostly male (81%), with cT3/T4 (68%), node negative (61%), M1 (58%) disease at diagnosis and ECOG PS 0–1. Metastases included lung (71%) and lymph nodes (58%). Pts received a median 6.5 cycles (range, 1 - 16). Treatment was moderately tolerable: grade 4 neutropenia (3 pts, 1 with fever), grade 4 dyspnea (1 pt), grade 4 peristomal infection (1 pt). 2 of 38 pts stopped treatment due to toxicity. 1 complete and 5 partial responses (PR) were observed (16%, 90% CI 7.1–28.8%). A 7th patient had an unconfirmed PR and an eighth patient had > 50 percent decrease in tumor burden after an initial progression. 9 patients had stable disease. Two pts are alive without progression (1 with a PFS of 2.5 years), 1 is alive with progression, and 35 patients have died. Median PFS is 3.5 months (95% CI 2.8–5.2 mos). Median OS is 8.8 mos (6.1–11.1 mos). Conclusions: Dox/Gem met efficacy criteria in RCC with sarcomatoid features. A TKI/Gem regimen in ECOG is planned.

No significant financial relationships to disclose.

Phase II study of recombinant IL-21 (rIL-21) plus sorafenib as second- or third-line therapy for metastatic renal cell cancer (mRCC): Final results

3023

Background: Despite the positive impact of targeted therapies on treatment for mRCC, the efficacy of these agents appears to decrease beyond the first-line setting. There is an unmet need for novel therapies after failure of vascular endothelial growth factor (VEGF)-directed agents. rIL-21, a cytokine that enhances CD8+ T-cell and NK cell activity, has single-agent antitumor activity (J Clin Oncol. 2008;26:2034). Based on promising results of a phase I study of rIL-21 plus sorafenib, we initiated a phase II study to explore the safety and efficacy of this combination as second- or third-line treatment for mRCC. Methods: Patients with mRCC received second- or third-line therapy with sorafenib 400 mg PO BID continuously plus rIL-21 30 μg/kg IV on days 1–5 and 15–19 of each 7-week treatment course (TC). Efficacy endpoints included progression-free survival (PFS) and overall response rate (ORR) per RECIST. Response was assessed by the investigator and by independent radiologic review (IRR). Results: 33 patients were enrolled from 14 sites in the U.S. and Canada. Median age was 61 years (range, 46–75); ECOG performance status was 0 (n=15) or 1 (n=18). Patients had received 1 (n=25) or 2 (n=8) prior lines of therapy, including sunitinib (n=19), temsirolimus (n=5), bevacizumab (n=3), everolimus (n=2), IL-2 (n=11), or other (n=4). Grade ≥3 adverse events considered at least possibly related to study drug and occurring in ≥3 patients included hypophosphatemia (33%), hand-foot syndrome (24%), rash (24%), thrombocytopenia (8%), and neutropenia (8%). Twelve patients remain on study; 13 withdrew for progressive disease (PD), 6 for toxicity, and 2 for other reasons. IRR has been performed for the first 23 patients who completed at least 1 full TC, with 6 confirmed PR (26%), 1 unconfirmed PR (4%), 14 SD (61%), and 2 PD (9%). While median PFS cannot yet be determined, 14 of the first 29 patients have completed at least 3 TCs, equivalent to approximately 21 weeks, with SD or better. Conclusions: rIL-21 plus sorafenib is associated with an acceptable safety profile and promising antitumor efficacy in previously treated patients with mRCC. The observed ORR to date compares favorably with the rate previously reported for sorafenib in the first and second-line setting.

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A phase I dose-escalation study of the safety, pharmacokinetics (PK), and pharmacodynamics of XL765, a PI3K/TORC1/TORC2 inhibitor administered orally to patients (pts) with advanced solid tumors

3502

Background: XL765 is a potent and selective inhibitor of Class I PI3K isoforms, TORC1, and TORC2. XL765 has shown dose-dependent target modulation and tumor growth inhibition or shrinkage in multiple human xenografts. Methods: Pts receive XL765 bid or qd for 28-day cycles. PK and pharmacodynamic analyses are performed. Tumor response is assessed by RECIST every 8 weeks. Results: To date, 34 pts have been dosed with XL765; 26 pts on a bid regimen (15–120mg) and 8 pts on a qd regimen (70–100 mg). Maximum administered doses are 120 mg bid and 100 mg qd. Dose-limiting toxicities (DLTs) occurred at 120 mg bid and 60 mg bid and included elevated hepatic transaminases (2), anorexia/hypophosphatemia (1), rash (1), and nausea/vomiting (1). Grade > 2 increase in transaminases, including one possibly related serious adverse event of Grade 4, occurred in 3 of 7 pts at 120 mg bid. Non-specific neurological complaints (1) and rash (1) were the DLTs that occurred at 100 mg qd. The most common (> 10% of pts) related adverse events were elevated liver enzymes, nausea and diarrhea. XL765 exposure increased with increasing doses (15–120 mg bid). Median tmax was 1–3 h post-dose. Mean t1/2,z ranged from 3 to 9 h at steady-state. Repeat dosing (bid or qd) resulted in moderate to no drug accumulation. XL765 augmented food-induced increases in plasma insulin, but not glucose, in an exposure-dependent fashion. Robust pharmacodynamic modulation of PI3K pathway signaling in PBMCs, hair follicles, skin, and tumors was evident following administration of XL765. These effects were exposure-dependent for some biomarkers in PBMCs and hair. Five pts had durable stable disease (> 3 months): appendiceal cancer (15 mg bid) 8 cycles; RCC (15 mg bid) 4 cycles; NSCLC (30 mg bid) 4 cycles; mesothelioma (60 mg bid) 10 cycles; CRC (100 mg qd) 6 cycles. Conclusions: In this phase I study, XL765 has exhibited potent pharmacodynamic activity at generally well tolerated doses. PI3K pathway inhibition of ∼60–90% in hair and skin was seen at multiple tolerable doses.

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Phase I experience with c-MET inhibitor XL880 administered orally to patients (pts) with solid tumors

3526

Background: XL880 is a sub-nM inhibitor of the hepatocyte growth factor receptor (Met) and VEGF receptor family with low in vitro nM inhibition of PDGFRβ, KIT, FLT3, Tie-2 and Ron. Methods: The safety of XL880 was evaluated in two phase 1 studies. XL880 was administered mass-based on a 5 days on / 9 days off schedule (study 1) or as a fixed daily dose (study 2). Inclusion criteria include ECOG performance status = 2, adequate liver, cardiac, and renal function and no brain metastases. Tumor response is assessed every 8 wks by RECIST criteria. Pharmacokinetics, pre and post treatment tumor biopsies and plasma markers of angiogenesis (VEGF, sVEGFR and Ang2) were collected. Results: To date, 51 pts have been dosed in studies 1 & 2. In study 1, dose limiting toxicities (DLT) included reversible Gr3 elevations of lipase, hepatic transaminases and proteinuria. The maximum tolerated dose (MTD) was 3.6 mg/kg. In study 2, the MTD has not been defined. Common adverse events include hypertension and fatigue with loss of concentration. In study 1, 5 of 40 pts had partial responses (2+ -12+ months[m]), 3 pts had minimal responses and 8 pts had stable disease (SD) > 3 m. In study 2, 5 of 8 evaluable pts had SD > 3 m (4 ongoing) and 3 are too early to evaluate. Correlative studies in tumor biopsies show marked inhibition of phospho (p)-met, p-RON, p- ERK, p-AKT and increased apoptosis at less than the MTD. Patients in study 2 pts showed lower XL880 Cmax values with consistent mean concentrations (Css)compared with study 1 MTD pts. Css levels are reached in 15 d. Conclusions: XL880 as daily oral or 5 day on / 9 day off administration is generally well tolerated for > 1 year, although hypertension is nearly universal but manageable. XL880 has demonstrated substantial phase I antitumor activity with both dosing regimens. Correlative studies indicate significant activity against Met and Ron signaling. Enrollment continues on study 2. Phase II trials in gastric cancer and head and neck cancer will begin soon.

No significant financial relationships to disclose.

A randomized, placebo-controlled trial of celecoxib in men prior to receiving prostatectomy for clinically localized adenocarcinoma of the prostate: Evaluation of drug-specific biomarker modulation

5001

Background: Cyclooxygenase-2 (COX-2) has been postulated as a pharmacological target for preventing a variety of epithelial malignancies including prostate cancer (PCa). We conducted a randomized, double-blind study evaluating celecoxib (C) on biomarkers in normal and PCa tissue at prostatectomy (RRP). Methods: Patients with Gleason sum ≥ 7, pre-study PSA ≥ 15 ng/ml, clinical stage T2b, T2c, or any combination of PSA, Stage, or two or more cores positive for PCa received either C at 400 mg po bid or placebo for 4–6 wks pre-RRP. The primary endpoint was to compare and correlate tissue PG levels with histologic and secondary endpoints performed on prostate tissue and serum from the two comparable groups. Outcomes included PG levels, quantitative RT-PCR for mRNA levels of COX-1 and COX-2, oxidized DNA bases; measurement of apoptosis, proliferation, angiogenic-potential assays and histologic comparison of treated/untreated tissue specimens; PSA levels; and tissue levels of C. Estimates of change in endpoints required 30 patients per arm. Results: Seventy three subjects consented with 64 randomized and included in the intent to treat analysis; 2 had missing data for primary endpoints. Age, baseline PSA, race and Gleason score were comparable across treatment groups. The regimen was well tolerated with no serious adverse events. There was no treatment effect observed in the PG, COX mRNA levels or oxidized DNA base levels in the RRP specimens. Tumor tissue contained significantly less COX-2 mRNA levels than benign tissue (p=<0.0001). Of the markers of apoptosis and proliferation assessed, Ki-67 was higher in tumor samples, and p21 was less in C treated samples. Celecoxib was present in tumor tissue demonstrating that it reached the target, but there were no observed effects in the study endpoints. There was no toxicity greater grade 1 except hepatic toxicity in a placebo group subject. Conclusions: Our results show a lack of effect of C on PCa despite demonstrating that C was present in tissue samples. At this time, we cannot recommend further studies of C as a PCa preventative agent when dosed at 400 mg PO BID. The study was supported by a grant from the NCI, DCP (#NO1-CN-95000–46) and Pfizer, Inc.

No significant financial relationships to disclose.