Intra-operative kinetics of anti-HLA antibody in simultaneous liver-kidney transplantation

During simultaneous liver-kidney transplantation (SLK) in highly sensitized patients, donor specific anti-human leukocyte antigen antibodies (DSA, HLA) can be present prior to transplant leading to positive crossmatch, yet these recipients have relatively low incidences of acute rejection. The mechanisms and timing underlying immunologic changes that occur intra-operatively remain largely unknown. Therefore, we measured the intra- and peri-operative kinetics of anti-HLA antibodies in highly sensitized SLK recipients. In this study, pre- and post-operative blood samples were obtained from sensitized SLK candidates with documented DSA. Intra-operative samples were obtained from a sub-group of SLK recipients. Pretransplant anti-HLA antibody profiles were created and flow cytometry and anti-human globulin complement-dependent cytotoxic crossmatches were performed. Significant reductions in anti-HLA class I and II DSA were seen intra-operatively shortly after reperfusion of the liver allograft. This effect was most pronounced for anti-HLA class I DSA (mean change, −85%, p < 0.05); changes to anti-HLA class II DSA were less robust (mean change, −47%, p = 0.15). Importantly, non-DSA anti-HLA antibodies remained unchanged throughout the perioperative period, suggesting the mechanism(s) by which the liver lowers DSA levels are specific to the DSA. These data demonstrate the immunologic benefit of performing SLK is lasting and occurs very shortly after liver reperfusion.

P1863Establishing safe working parameters for radio frequency catheterization along with acoustic sensing

Background

Studies comparing angles of application in Radio Frequency (RF) catheter ablation other than 0 and 90 degrees are absent from the literature. Likewise, using acoustics to predict steam pop occurrences and prevent a catastrophic rupture of the myocardium has not been examined previously.

Purpose

Evaluate the effect of various parameters on the ablated volume and the probability of creating a boiling pop.

Methods

A low-cost testing and educational platform to work with generic RF catheters was set up. The in-vitro system allows controlling the blood flow surrogate over the cardiac tissue, the catheter contact force, electric power, and ablation time. Acoustic transducers have been employed with the setup to detect preliminary acoustic signals.

Results

Obtained results show a positive correlation between variations of the ablated surface geometry and power intensity changes. Generated figures provide percentages of a boiling pops for any given set of parameters fig1 (Top left: Probability of popping vs power and time). The probability of a boiling pop occurring increased if the ovine specimen is non-irrigated. The ratio of the burn correlates with the power and the angle of the catheter (30°, 45°, 60°, and 90°). However, the probability of the popping mostly depends on the power fig1 (Top right: Burn ratio vs power for 30°, 45°, 60°, and 90°) and fig1 (Bottom right: Cross sectional view of the corresponding lesions -same scale used for all images). Benign precursory bubbles detected by acoustics preceded the occurrence of catastrophic boiling pops fig1 (Bottom left: Acoustic signal showing a precursory pop before the major cavitation).

Figure 1

Conclusion

The established parameters for power intensity and exposure time should be respected to maintain a safe procedure. Acoustics can be further implemented to provide a warning for electrophysiologists before the occurrence of a boiling pop.

Acknowledgement/Funding

The funding for this project was provided from the URB and the MPP at the AUBMC and the AUB.

P14.99 Clinical and biologic features predictive of survival after relapse of childhood medulloblastoma

BACKGROUND

Salvage therapy for recurrent medulloblastoma (MB) is not standardized. Factors associated with survival after recurrence have not been reported.

MATERIAL AND METHODS

Medical records were reviewed for 155 consecutive patients with newly diagnosed MB between 2007 and 2017, treated at Gustave Roussy and Hospital Necker. The following variables were collected for all patients: age at diagnosis, stage, histology (central review according to WHO 2016 classification), molecular subgrouping (DNA methylation), first-line treatment modalities, time to relapse, pattern of recurrence and current status.

RESULTS

A disease recurrence was observed in 47 patients (30%) at a median time of 15 months (range, 1–88 months). The 1-year survival after recurrence was 44% (CI 95%,29.6 to 58.8). The pattern of recurrence was local in 9 patients, metastatic in 21 and combined local and metastatic in 17 patients. The time to first recurrence, less or more than 12 months from diagnosis, was a predictor of post-recurrence overall survival (p < 0.0001) after adjustment for age, treatment, MYC amplification and molecular subgroups. Twenty-seven patients (57%) experiencing recurrent or progressive disease more than 12 months after diagnosis, had an estimated 1-year survival after recurrence of 100% (CI 95%, 100.0 to 100.0) vs 30% (CI 95%, 12.2 to 50.1) with an earlier recurrence. Early relapse was more frequent in children younger than 5 years of age at diagnosis (75% vs 37%, p =0.009), anaplastic/large cell MB (30% vs 3.7%, p=0.046) and Group 3 tumours (76.5% vs 20.8%, p=0.003). Other factors influencing post-relapse survival were metastatic disease and treatment modalities at diagnosis. Multivariable analyses will be presented.

CONCLUSION

The overall prognosis after relapse remains poor. Time to relapse is a significant prognostic factor for postrelapse survival and may help in the design of clinical trials evaluating new agents.

Soluble CD163 is a biomarker for accelerated atherosclerosis in systemic lupus erythematosus patients at apparent low risk for cardiovascular disease

Objective: This study aimed to determine whether sCD163, a soluble macrophage marker up-regulated in numerous inflammatory disorders, is predictive of accelerated atherosclerosis associated with systemic lupus erythematosus (SLE).Methods: Carotid ultrasound was prospectively performed, at baseline and during follow-up, in 63 consecutive SLE patients asymptomatic for cardiovascular disease (CVD) and 18 volunteer health workers. Serum sCD163 level was determined at baseline using enzyme-linked immunosorbent assay. The primary outcome was the presence of a carotid plaque. Factors associated with carotid plaques were identified through multivariate analysis.Results: Despite a low risk for cardiovascular events according to Framingham score in both groups (2.1 ± 3.8% in SLE vs 2.1 ± 2.9% in controls; p = 0.416), ultrasound at baseline showed a carotid plaque in 23 SLE patients (36.5%) and two controls (11.1%) (p = 0.039). Multivariate analysis showed that SLE status increased the risk for carotid plaque by a factor of 9 (p = 0.017). In SLE patients, sCD163 level was high (483.7 ± 260.8 ng/mL vs 282.1 ± 97.5 ng/mL in controls; p < 0.001) and independently associated with carotid plaques, as assessed by stratification based on sCD163 quartile values (p = 0.009), receiver operating characteristics (p = 0.001), and multivariate analysis (p = 0.015). sCD163 at baseline was associated with the onset of carotid plaque during follow-up (3 ± 1.4 years) in SLE patients who had no carotid plaque at the first evaluation (p = 0.041).Conclusion: sCD163 is associated with progressing carotid plaque in SLE and may be a useful biomarker for accelerated atherosclerosis in SLE patients at apparent low risk for CVD.

New Simplified Screening Method for Postprandial Hypotension in Older People

BACKGROUND

Postprandial hypotension (PPH) is an important disorder in the older people that remain underdiagnosed. The reference PPH diagnostic method is too demanding, because blood pressure (BP) needs to be measured 8 times in 2 hours.

OBJECTIVES

Our primary objective was to define a new simplified PPH diagnostic method and to evaluate its performances.

DESIGN

We conducted a cross-sectional study.

SETTING

Two geriatric rehabilitation units in France.

PARTICIPANTS

104 patients (70 women, 34 men) with high risk of PPH were included.

MEASUREMENTS

BP was measured twice before the midday meal in seated position at the table, and every 15 minutes for 90 minutes after the end of the meal. Receiver Operating Characteristic curves were plotted for each postprandial BP measure to determine the best postprandial measure in terms of sensitivity and specificity. The optimal diagnostic threshold was calculated with Youden's index according to BP difference before and after the meal.

RESULTS

A new simplified diagnostic method is proposed: a decrease of at least 10 mmHg systolic BP between BP measures before the meal and 75 minutes after the end of the meal. This new method had a sensitivity of 82% (95%CI 66 - 92) and a specificity of 91% (95%CI 81 - 97).

CONCLUSION

This new diagnostic method is fast, efficient and suitable for everyday use. It could improve PPH diagnosis in older people. Larger studies are needed to validate it.

Outcomes of combined tibial tuberosity transfer and medial patellofemoral ligament reconstruction for recurrent patellar instability

Patellofemoral instability is multifactorial and is associated with pathomechanics secondary to anatomical variance. Surgical management of this problem must be tailored to each patient and a thorough clinical and radiological assessment of the anatomical alignment should be carried out pre-operatively. The aim of this study is to assess the role of medial patellofemoral ligament reconstruction combined with tibial tuberosity transfer in patients with increased tibial tuberosity to trochlear groove (TT-TG) distance. Twenty-four patients (27 knees) over 2-years were operated on by a single surgeon, with standardised post-operative rehabilitation and follow up. Mean follow up was 31-months. Two patients had problems with recurrent instability, 1 had a -traumatic re-dislocation at 2 years and a total of 4 required further operation for complications. Mean post--operative Kujala scores were 87.4 (SD 9.8). Combined medial patellofemoral ligament reconstruction and tibial tuberosity transfer is an appropriate treatment for patients with increased TT-TG distance.

Prospective mid-term results of a consecutive series of a short stem

A large number of short stem prostheses for hip -arthroplasty have been introduced in the past years. Although there is a large increase of publications about short stems, there is still little data available about survival and revision rates. We report prospectively on the outcome of 84 consecutive NANOS® short stem prostheses in 81 patients. We have included 37 female patients and 44 male patients with an average age of 61.6 ± 9.2 years. The main diagnoses were osteoarthritis in 67 patients, dysplastic osteoarthritis in 8 patients and avascular necrosis of the femoral head in 6 patients. Along with demographic data and co-morbidities, the Harris Hip Score was recorded preoperatively and at follow-up. The Harris Hip Score increased from 36.6 ± 14.5 preoperatively to 94.5 ± 8.8 at the final follow-up. During the main follow-up time (27.7 months ± 5.7) none of the 84 stems were revised, intraoperatively three fissure fractures occurred.

[A new classification for meibomian gland diseases with in vivo confocal microscopy]

INTRODUCTION

Meibomian gland dysfunction (MGD) is a frequent disorder often associated with dry eye disease. Slit-lamp examination with digital expression of the tarsal Meibomian glands allows examination of the contents of the distal Meibomian gland and the meatus. However, the Meibomian epithelium, interglandular space and proximal secretions cannot be clinically assessed. In vivo confocal microscopy (IVCM) is a rapid and non-invasive imaging technique that provides high-resolution images of the ocular surface and eyelids. The primary objective of the present study was to establish a classification of MGD with IVCM. Secondary objectives were to evaluate this scoring system by analyzing the correlation with OSDI, infrared (IR) meibography and Demodex infestation.

MATERIAL AND METHODS

Forty-six dry eye patients (Ocular Surface Disease Index [OSDI] >13) associated with MGD were enrolled. Ten healthy subjects without dry eye disease or blepharitis were also included as controls. An OSDI questionnaire, clinical examination, IVCM and infrared meibography of the lower lid were performed in all subjects by the same examiner.

RESULTS

A new MGD score was established based on IVCM findings: the first stage was Meibomian obstruction with a clear epithelium, the second stage was an inflammatory state with Meibomian gland obstruction, epithelial and interglandular inflammation, and the last stage was glandular fibrosis. This score was significantly correlated with the meiboscore obtained with infrared meibography (correlation coefficient 0.47, CI95% [0.22-0.66]).

CONCLUSION

IVCM of the Meibomian gland complex complements the clinical examination by determining the stage of dysfunction and may help clinicians evaluate and treat MGD.

[Comparison of British and French expatriate doctors' characteristics and motivations]

BACKGROUND

Migration of medical practitioners is rarely studied despite its importance in medical demography: the objective of this study was to analyze the characteristics and motivations of the French doctors settled in the United Kingdom and of the British doctors settled in France.

METHODS

This cross-sectional study was conducted using a self-completed questionnaire sent to all French doctors practicing in the United Kingdom (in 2005) and all British medicine doctors practicing in France (in 2009). The doctors were identified with official data from the National Medical Councils: 244 French doctors practicing in the United Kingdom and 86 British doctors practicing in France. The questionnaire was specifically developed to determine the reasons of moving to the other country, and the level of satisfaction after expatriation.

RESULTS

A total of 98 French doctors (out of 244) and 40 British doctors (out of 86) returned the questionnaire. Respondents were mainly general practitioners with a professional experience of 8 to 9 years. The sex ratio was near 1 for both groups with a majority of women among physicians under 50 years. The motivations were different between groups: French doctors were attracted by the conditions offered at the National Health Service, whereas British doctors were more interested in opportunities for career advancement, joining husband or wife, or favourable environmental conditions. Overall, the respondents considered expatriation as satisfactory: 84% of French doctors, compared with only 58% of British doctors, were satisfied with their new professional situation.

CONCLUSION

This study, the first in its kind, leads to a clearer understanding of the migration of doctors between France and the United Kingdom.

Yoga for high-risk pregnancy: a randomized controlled trial

Background:

Improvements in technology have increased the chances of survival for the micro-premature infant and the very low birth-weight infant but have significantly increased the financial burden of health care organizations. This economic burden has a significant impact on third-party payers and on society in general.

Aim:

The study was designed to assess yoga therapy (YT) module on maternal stress level in high risk pregnancy.

Subjects and Methods:

In the present study, sixty-eight pregnant women (38 in the control group with standard antenatal care and 30 in the YT group) with 27.2 (5.2) years of mean age recruited from the outpatient services of medical college and hospital in Bangalore, South India, were participated. The study was a single-blind randomized controlled clinical trial. Perceived stress scale (PSS) was measured during the 12^th, 20^th, and 28^th weeks of pregnancy. SPSS version 16.0 (Chicago, IL, USA) was used for all data analysis. When the data were found to be normally distributed, the RMANOVA were used to assess the PSS scores between the yoga and control groups. Significant values were set at P < 0.05.

Results:

There was a significant difference in the PSS level of the YT group with significantly reduced scores at the second follow-up (28^th week of pregnancy) compared to the control group (P = 0.02). Women who took part in the YT module reported significantly fewer pregnancy discomforts decrease in PSS (P = 0.02) than the control group where the stress level was increased (RMANOVA test using SPSS-16).

Conclusion:

The present study suggests that the YT module can decrease the stress level during high-risk pregnancy complications. Thus, practicing YT during high-risk pregnancy is not only a cost-effective option but also a feasible and safe option. Additional well-designed studies are needed before a strong recommendation can be made.

Combination neratinib (HKI-272) and paclitaxel therapy in patients with HER2-positive metastatic breast cancer

INTRODUCTION

Neratinib is a potent irreversible pan-ErbB tyrosine kinase inhibitor that has demonstrated antitumour activity and an acceptable safety profile in patients with human epidermal growth factor receptor (HER)-2-positive breast cancer and other solid tumours.

METHODS

This was a phase I/II, open-label, two-part study. Part 1 was a dose-escalation study to determine the maximum tolerated dose (MTD) of neratinib plus paclitaxel in patients with solid tumours. Part 2 evaluated the safety, efficacy, and pharmacokinetics of the combination at the MTD in patients with HER2-positive breast cancer.

RESULTS

Eight patients were included in the dose-escalation study; no dose-limiting toxicities were observed, and an MTD of oral neratinib 240 mg once daily plus intravenous paclitaxel 80 mg m(-2) on days 1, 8, and 15 of each 28-day cycle was determined. A total of 102 patients with HER2-positive breast cancer were enrolled in part 2. The overall median treatment duration was 47.9 weeks (range: 0.1-147.3 weeks). Common treatment-emergent adverse events (all grades/grade ≥3) included diarrhoea (92%/29%; none grade 4), peripheral sensory neuropathy (51%/3%), neutropenia (50%/20%), alopecia (46%/0%), leukopenia (41%/18%), anaemia (37%/8%), and nausea (34%/1%). Three (3%) patients discontinued treatment due to an adverse event (mouth ulceration, left ventricular ejection fraction reduction, and acute renal failure). Among the 99 evaluable patients in part 2 of the study, the overall response rate (ORR) was 73% (95% confidence interval (CI): 62.9-81.2%), including 7 (7%) patients who achieved a complete response; an additional 9 (9%) patients achieved stable disease for at least 24 weeks. ORR was 71% among patients with 0/1 prior chemotherapy regimen for metastatic disease and no prior lapatinib, and 77% among those with 2/3 prior chemotherapy regimens for metastatic disease with prior lapatinib permitted. Kaplan-Meier median progression-free survival was 57.0 weeks (95% CI: 47.7-81.6 weeks). Pharmacokinetic analyses indicated no interaction between neratinib and paclitaxel.

CONCLUSION

The combination of neratinib and paclitaxel was associated with higher toxicity than that of neratinib as a single agent, but was manageable with antidiarrhoeal agents and dose reductions in general. The combination therapy also demonstrated a high rate of response in patients with HER2-positive breast cancer. A phase III trial is ongoing to assess the benefit and risk of this combination in the first-line setting.

Safety and efficacy of neratinib (HKI-272) in combination with paclitaxel in patients with solid tumors

3557

Background: Neratinib (HKI-272) is a potent irreversible pan-ErbB inhibitor of the tyrosine kinase receptors, erbB-1,-2 and -4. In this phase 1 study, a combination dose of neratinib plus paclitaxel that is tolerable was determined in patients (pts) with solid tumors, and safety and preliminary efficacy were assessed in pts with erbB-2+ metastatic breast cancer. Methods: In this open label, 2-part study, ascending multiple daily oral doses of neratinib (160 mg, 240 mg) were administered in combination with IV paclitaxel 80 mg/m2, if tolerable, or 70 mg/m2 on days 1, 8 and 15. Pts with solid tumors and pts with only metastatic erbB-2+ breast cancer are enrolled in part 1 and 2, respectively. Tumor measurements were made at screening and at every 8 weeks (2 cycles) by modified RECIST criteria. Timed blood samples were collected for neratinib and paclitaxel plasma concentration determination, and PK analyses were performed using a noncompartmental method. Results: Data for 54 pts as of 30 Oct 2008 are presented (median age [range] of 51.5 [20–74] yrs; 91% female; 26 % with prior trastuzumab treatment of median duration [range] 32.5 [10–52] wks; 15% with prior lapatinib treatment). Tumor types in part 1 included breast, endometrial, cervical, colorectal and esophageal cancer. There were no dose-limiting toxicities (DLTs) at the 240 mg neratinib-80 mg/m2 paclitaxel dose, and as standard doses of neratinib and paclitaxel were reached, there was no reason for further escalation. Neratinib-related AEs, any grade in ≥10% of pts included diarrhea (50%), neutropenia (17%), rash (13%), nausea (11%) and vomiting (11%). Neratinib- related AEs, grade ≥3 in ≥2% of pts were diarrhea (20%), neutropenia (9%) and dehydration (4%). Only 2 pts (at the 240 mg neratinib-80 mg/m2 paclitaxel dose) had dose reductions due to diarrhea. In 35 efficacy evaluable pts, 5 had confirmed partial response (PR). Confirmed clinical benefit (PR and prolonged disease stabilization) was seen in 2 pts in part 1, 1 pt with endometrial cancer and 1 pt with cervical cancer. Conclusions: This combination of 240 mg neratinib and 80 mg/m2 paclitaxel was tolerable with a toxicity profile similar to that observed for neratinib, and had promising antitumor activity in pts with solid tumors and erbB-2 + breast cancer.

[Table: see text]

Neratinib in combination with trastuzumab for the treatment of advanced breast cancer: A phase I/II study

1004

Background: Neratinib (HKI-272) is an orally administered irreversible pan-ErbB receptor tyrosine kinase inhibitor. In an ongoing phase II study, the preliminary objective response rate was 26% in patients with ErbB2+ advanced breast cancer with prior trastuzumab therapy. This study assessed the safety and preliminary efficacy of the combination of neratinib plus trastuzumab. Methods: Patients with advanced ErbB2+ breast cancer that progressed following trastuzumab therapy were enrolled. The primary endpoint was 16-week progression free survival rate (PFS). In part 1 (dose escalation), patients received neratinib 160 mg or 240 mg daily plus trastuzumab 4 mg/kg IV loading dose then 2 mg/kg weekly. In part 2, patients received weekly trastuzumab with neratinib 240 mg daily. Timed blood samples were collected for PK analyses. PK analysis is ongoing. Results: 45 patients (part 1 n = 8; part 2 n = 37) were enrolled (mean age 52 yr); 9 are active. In part 1, cohorts 1 and 2 were fully enrolled with 4 patients each. No dose limiting toxicities were observed. Most common AEs, any grade, were diarrhea (91%), nausea (51%), anorexia (40%), vomiting (38%), and asthenia (27%). Grade 3/4 AEs were diarrhea (13%), nausea (4%), vomiting (4%). Two patients receiving neratinib 240 mg reported AEs leading to withdrawal. No AEs of congestive heart failure and no significant drops of left ventricular ejection fraction were reported. Among 33 patients evaluable for efficacy, objective response rate was 27% (95% CI, 13% - 46%); 16-week PFS rate (for part 2) 47% (95% CI, 29% - 63%); median PFS was 19 weeks (95% CI 15 - 32 weeks). Conclusions: Neratinib plus trastuzumab was well tolerated with no significant or unexpected toxicities, and demonstrated clinical activity.

[Table: see text]

Development of a swine model of secondary liver tumor from a genetically induced swine fibroblast cell line

AIM

Metastatic disease is the most common liver tumor. Although alternative therapies have been developed for non-surgical candidates, those therapies lacked ideal testing prior to clinical application because of a paucity of large animal models. The purpose of the present study was to develop a model for secondary liver tumor in a large animal.

MATERIAL AND METHODS

Fibroblasts were isolated from swine ear lobules and then transfected with amphotrophic retroviruses encoding human or murine genetic material (hTERT, p53(DD), cyclinD-1, CDK4(R24C), Myc (T58A), Ras(G12V)). Transformed cell lines were finally inoculated subcutaneously (s.c.) into: 1) immunodeficient mice (nude), 2) immunocompetent mice (wild type), 3) immunosuppressed swine (under tacrolimus or corticosteroids), 4) immunocompetent swine, and 5) into the liver and portal circulation of swine under steroid-based immunosuppression.

RESULTS

In the murine model, tumor growth was evident in 100% of the nude mice (n=5), with a peak size of 20 mm (15.22+/-4.5 mm; mean+/-SD) at the time of sacrifice (3 weeks). Tumor growth was evident in 71% of the wild mice (n=21), with a peak size of 7.8 mm (4.19+/-1.1 mm) by the third week of growth. In the swine model, tumor growth was evident in 75% (3/4 ears; n=2) of swine under tacrolimus-based immunosuppression versus 50% of swine under steroids-based immunosuppression (n=2). Tumor growth was slow in two animals, while in one animal the tumor was larger with a peak growth of 42 mm at 3 weeks. The tumor pattern in the ear lobules was characterized by slow growth, with a peak size of 6-8 mm in the immunocompetent swine at 3 weeks. All tumors were shown to be malignant by histology. In contrast, inoculums of the transformed fibroblast cell line in swine livers showed no evidence of tumor growth at 3 weeks.

CONCLUSIONS

Development of a transformed swine fibroblast cell line was successful, resulting in an in vivo malignant tumor. Cell line inoculums had tumorigenic properties in nude mice, wild-type mice, and immunosuppressed swine, as judged by uncontrolled cell growth, invasion of surrounding tissue, neoangiogenesis, and invasion of normal vasculature, resulting in the formation of tumor nodules. Such properties were not observed in swine upon inoculation into the liver/portal circulation.

Bosutinib (SKI-606) exhibits clinical activity in patients with Philadelphia chromosome positive CML or ALL who failed imatinib

7006

Background: Bosutinib (SKI-606) is an orally available, dual Src/Abl kinase inhibitor. To assess safety and preliminary clinical activity of bosutinib, we conducted a phase 1/2 study in patients (pts) with Philadelphia chromosome positive (Ph+) chronic myelogenous leukemia (CML) or acute lymphocytic leukemia (ALL) who were imatinib resistant/intolerant. Methods: In part 1, 18 pts with imatinib- relapsed/refractory chronic phase (CP) CML received bosutinib 400 mg/day (3 pts), 500 mg/day (3 pts), or 600 mg/day (12 pts). Part 2 was an expanded cohort of 51 pts with all phases of Ph+ CML and ALL dosed at 500 mg daily. Timed blood samples were collected on days 1–3, 15 for PK analysis. Results: Of 69 pts, median age was 59 yrs; 48 were CP; 90% imatinib resistant. Drug-related grade 1/2 adverse events (AEs) occurring in =10% of CP pts: diarrhea (69%), nausea (44%), vomiting (19%), abdominal pain (13%), rash (13%). Grade 3/4 AEs occurring in =5% of CP pts: rash (6%), thrombocytopenia (6%). 17 pts required dose reductions. In evaluable imatinib-resistant CP-CML pts with no prior exposure to other Abl inhibitors, 16/19 (84%) had complete hematologic response (CHR); 4/21 had partial and 7/21 had complete cytogenetic responses for major cytogenetic response (MCyR) rate of 52%. Of 58 pts evaluable for mutations, 13 different imatinib-resistant mutations were found in 32 pts. 12/14 CP pts with non-P-loop mutations and 3/3 with P-loop mutations achieved CHR. 5/11 CP pts with non-P- loop mutations and 1/1 with P-loop mutation achieved MCyR. 4/9 evaluable advanced leukemia pts had CHR, 2 had MCyR. After oral administration, steady state exposure of bosutinib was nearly 2-fold higher than single-dose exposure. Mean elimination half-life was approximately 22–27 hours, supporting a once-daily dosing regimen. Conclusions: Bosutinib was well tolerated in pts with CML, with primarily low-grade gastrointestinal and dermatologic AEs. Bosutinib showed clinical activity in imatinib-resistant pts with cytogenetic responses and CHR across a range of mutations. Durability of response continues to be assessed.

[Table: see text]

Bosutinib (SKI-606), a dual Src/Abl tyrosine kinase inhibitor: Preliminary results from a phase 1 study in patients with advanced malignant solid tumors

3552

Background: Bosutinib (SKI-606) is a potent, low molecular weight, orally active, competitive inhibitor of both Src and Abl tyrosine kinases. Elevations of Src kinase activity occur in a variety of human tumor types and are correlated with aggressiveness. We conducted a phase 1 study in patients (pts) with advanced solid tumors to assess tolerability, safety, pharmacokinetics (PK), and preliminary antitumor activity of bosutinib. Methods: Patients in cohorts of 3–6 received 50, 100, 200, 300, 400, 500 or 600 mg bosutinib orally on study day 1 and then once daily beginning on day 3. Timed blood samples were collected on days 1–3, 15 and 16 for PK analysis. Tumor assessments (modified RECIST criteria) were made at baseline and the end of every third cycle (21 days/cycle). Collection of tissue samples for analysis of Src biomarkers was optional. Results: Preliminary data are presented for 51 pts (median 57 years, 57% women). Three pts who received 600 mg bosutinib/day had drug-related dose-limiting toxicity of grade 3 diarrhea (2 pts) and grade 3 rash (1 pt). Gastrointestinal (GI) toxicity was reported among 6 pts in the 500-mg maximum tolerated dose (MTD) lead-in cohort so that 400 mg was selected as the MTD. Drug-related adverse events (AEs), any grade, occurring in =25% of pts were nausea (67%), diarrhea (55%), anorexia (45%), vomiting (43%), asthenia (41%). The only grade 3 drug-related AE occurring in =5% of pts was diarrhea (14%). After oral administration, bosutinib exposure increased in a dose-dependent manner. Multiple-dose exposure was nearly 2- to 3-fold higher than single-dose exposure. Mean elimination half-life was approximately 17 to 21 hours, supporting a once-daily dosing regimen. Six pts had stable disease >15 weeks (2 pts each with breast, colorectal cancer, non-small cell lung cancer [NSCLC]) and 1 pt had stable disease >52 weeks (pancreatic cancer). Conclusions: Bosutinib was generally well tolerated with predominantly gastrointestinal AEs. Accrual and evaluation of an expanded cohort restricted to patients with colorectal, pancreatic, and NSCLC tumors is ongoing. The patient with pancreatic cancer has had stable disease >52 weeks.

No significant financial relationships to disclose.

HKI-272, an irreversible pan erbB receptor tyrosine kinase inhibitor: Preliminary phase 1 results in patients with solid tumors

3018

Background: HKI-272 is a potent, low molecular weight, orally active, irreversible pan erbB receptor tyrosine kinase inhibitor. It inhibits the growth of tumor cells that express erbB-1 (epidermal growth factor receptor, EGFR) and erbB-2 (HER-2) in culture and xenografts. HKI-272 also inhibits the growth of cultured cells that contain sensitizing and resistance-associated EGFR mutations (Kwak et al, Proc Natl Acad Sci USA 102:7665–70, 2005). We are conducting a phase 1 study in patients (pts) with advanced-stage tumors that express EGFR or HER-2 to assess HKI-272 for tolerability, safety, pharmacokinetics, and preliminary antitumor activity. Methods: Pts (3–6/cohort) received 40, 80, 120, 180, 240, 320, or 400 mg HKI-272 orally once on day 1 and then once daily beginning on day 8. Timed blood samples were collected on days 1 and 21 for pharmacokinetic analysis. Results: Enrollment of 73 pts is complete. Preliminary data for 51 pts as of 28 Nov 2005 are presented. Patients were a median 60 years and 26% men. The most frequently occurring tumor types at primary diagnosis were breast (23 pts), non-small cell lung (9), and colorectal, ovarian, and renal (3 pts each). Dose escalation ended when 2 pts who received 400 mg HKI-272/day had drug-related dose-limiting toxicity of grade 3 diarrhea. Thus, the maximum tolerated dose (MTD) was 320 mg HKI-272/day. HKI-272-related adverse events (AEs), any grade, that occurred in ≥10% of pts were diarrhea (84%), nausea (55%), asthenia (45%), anorexia (31%), vomiting (29%), chills (12%), and rash (10%). Grade 3 related AEs that occurred in >1 pt were diarrhea (11) and asthenia (4). HKI-272 Cmax and AUC increased in a dose-dependent manner. At steady state at the MTD, mean values were Cmax: 112±58 ng/mL, AUC: 1618±930 ng.h/mL, t1/2: 15±2.5 h. Day 1 and 21 AUC values were comparable. Tumor assessments (modified RECIST criteria) were made at baseline and at the end of alternate cycles (28 days/cycle). Two breast cancer pts had confirmed partial responses (PRs) and 2 had unconfirmed PRs. Conclusions: When HKI-272 was administered on a continuous, once-daily, oral treatment schedule, the MTD was 320 mg/day, with diarrhea as the most frequently occurring related AE. HKI-272 has antitumor activity in HER-2-positive breast cancer.

[Table: see text]

A novel per-oral insulin formulation: proof of concept study in non-diabetic subjects

AIMS

The aim of our study was to examine the absorption of insulin from the gastrointestinal (GI) tract, using a novel oral formulation-adding a delivery agent SNAC (sodium N-[8-(2-hydroxybenzoyl)amino] caprylate) in combination with insulin.

METHODS

Capsules containing insulin and SNAC, in various combinations, were administered orally, as a single dose, to 12 non-diabetic subjects and four control subjects (receiving SNAC or insulin only) in order to assess its biological effect and safety. Plasma glucose levels, insulin and C-peptide concentrations, as well as SNAC levels, were determined, at timed intervals up to 4 h.

RESULTS

In all cases, a glucose-lowering effect was demonstrated, preceded by an increase in plasma insulin levels. The nadir of plasma glucose levels appeared after 30-50 min, following the ingestion of the mixture. The plasma insulin levels were found to parallel the blood SNAC levels. Plasma C-peptide levels were suppressed by the lowered glucose levels achieved concurrent with the increasing amount of exogenous insulin absorbed, indicating that the secretion of endogenous hormone was partially abolished. There were no biological effects regarding blood glucose levels upon administration of SNAC or insulin when given alone. No adverse effects were detected during the trial or several weeks after the trial.

CONCLUSIONS

Insulin in combination with a novel delivery agent, SNAC, given orally, is absorbed through the GI tract in a biologically active form. This was demonstrated by a glucose lowering effect of the mixture as well as a suppression of an endogenous insulin secretion.

In vitro metabolism and interaction of cilostazol with human hepatic cytochrome P450 isoforms

1. Cilostazol (OPC-13013) undergoes extensive hepatic metabolism. The hydroxylation of the quinone moiety of cilostazol to OPC-13326 was the predominant route in all the liver preparations studies. The hydroxylation of the hexane moiety to OPC-13217 was the second most predominant route in vitro. 2. Ketoconazole (1 microM) was the most potent inhibitor of both quinone and hexane hydroxylation. Both the CYP2D6 inhibitor quinidine (0.1 microM) and the CYP2C19 inhibitor omeprazole (10 microM) failed to consistently inhibit metabolism of cilostazol via either of these two predominant routes. 3. Data obtained from a bank of pre-characterized human liver microsomes demonstrated a stronger correlation (r2=0.68, P < 0.01) between metabolism of cilostazol to OPC-13326 and metabolism of felodipine, a CYP3A probe, that with probes for any other isoform. Cimetidine demonstrated concentration-dependent competitive inhibition of the metabolism of cilostazol by both routes. 4. Kinetic data demonstrated a Km value of 101 microM for cilostazol, suggesting a relatively low affinity of cilostazol for CYP3A. While recombinant CYP1A2, CYP2D6 and CYP2C19 were also able to catalyze formation of specific cilostazol metabolites, they did not appear to contribute significantly to cilostazol metabolism in whole human liver microsomes.

Identification of S-(1,2-dichlorovinyl)glutathione in the blood of human volunteers exposed to trichloroethylene

Healthy male and female human volunteers were exposed to 50 ppm or 100 ppm trichloroethylene (Tri) by inhalation for 4 h. Blood and urine samples were taken at various times before, during, and after the exposure period for analysis of glutathione (GSH), related thiols and disulfides, and GSH-derived metabolites of Tri. The GSH conjugate of Tri, S-(1,2-dichlorovinyl)glutathione (DCVG), was found in the blood of all subjects from 30 min after the start of the 4-h exposure to Tri to 1 to 8 h after the end of the exposure period, depending on the dose of Tri and the sex of the subject. Male subjects exposed to 100 ppm Tri exhibited a maximal content of DCVG in the blood at 2 h after the start of the exposure of 46.1 +/- 14.2 nmol/ml (n = 8), whereas female subjects exposed to 100 ppm Tri exhibited a maximal content of DCVG in the blood at 4 h after the start of the exposure of only 13.4 /- 6.6 nmol/ml (n = 8). Pharmacokinetic analysis of blood DCVG concentrations showed that the area under the curve value was 3.4-fold greater in males than in females, while the t1/2 values for systemic clearance of DCVG were similar in the two sexes. Analysis of the distribution of individual values indicated a possible sorting, irrespective of gender, into a high- and a low-activity population, which suggests the possibility of a polymorphism. The mercapturates N-acetyl-1,2-DCVC and N-acetyl-2,2-DCVC were only observed in the urine of 1 male subject exposed to 100 ppm Tri. Higher contents of glutamate were generally found in the blood of females, but no marked differences between sexes were observed in contents of cyst(e)ine or GSH or in GSH redox status in the blood. Urinary GSH output exhibited a diurnal variation with no apparent sex- or Tri exposure-dependent differences. These results provide direct, in vivo evidence of GSH conjugation of Tri in humans exposed to Tri and demonstrate markedly higher amounts of DCVG formation in males, suggesting that their potential risk to Tri-induced renal toxicity may be greater than that of females.

A human physiologically based pharmacokinetic model for trichloroethylene and its metabolites, trichloroacetic acid and free trichloroethanol

Nine male and eight female healthy volunteers were exposed to 50 or 100 ppm trichloroethylene vapors for 4 h. Blood, urine, and exhaled breath samples were collected for development of a physiologically based pharmacokinetic (PBPK) model for trichloroethylene and its two major P450-mediated metabolites, trichloroacetic acid and free trichloroethanol. Blood and urine were analyzed for trichloroethylene, chloral hydrate, free trichloroethanol and trichloroethanol glucuronide, and trichloroacetic acid. Plasma was analyzed for dichloroacetic acid. Trichloroethylene was also measured in exhaled breath samples. Trichloroethylene, free trichloroethanol, and trichloroacetic acid were found in blood samples of all volunteers and only trace amounts of dichloroacetic acid (4-12 ppb) were found in plasma samples from a few volunteers. Trichloroethanol glucuronide and trichloroacetic acid were found in urine of all volunteers. No chloral hydrate was detected in the volunteers. Gender-specific PBPK models were developed with fitted urinary rate constant values for each individual trichloroethylene exposure to describe urinary excretion of trichloroethanol glucuronide and trichloroacetic acid. Individual urinary excretion rate constants were necessary to account for the variability in the measured cumulative amount of metabolites excreted in the urine. However, the average amount of trichloroacetic acid and trichloroethanol glucuronide excreted in urine for each gender was predicted using mean urinary excretion rate constant values for each sex. A four-compartment physiological flow model was used for the metabolites (lung, liver, kidney, and body) and a six-compartment physiological flow model was used for trichloroethylene (lung, liver, kidney, fat, and slowly and rapidly perfused tissues). Metabolic capacity (Vmaxc) for oxidation of trichloroethylene was estimated to be 4 mg/kg/h in males and 5 mg/kg/h in females. Metabolized trichloroethylene was assumed to be converted to either free trichloroethanol (90%) or trichloroacetic acid (10%). Free trichloroethanol was glucuronidated forming trichloroethanol glucuronide or converted to trichloroacetic acid via back conversion of trichloroethanol to chloral (trichloroacetaldehyde). Trichloroethanol glucuronide and trichloroacetic acid were then excreted in urine. Gender-related pharmacokinetic differences in the uptake and metabolism of trichloroethylene were minor, but apparent. In general, the PBPK models for the male and female volunteers provided adequate predictions of the uptake of trichloroethylene and distribution of trichloroethylene and its metabolites, trichloroacetic acid and free trichloroethanol. The PBPK models for males and females consistently overpredicted exhaled breath concentrations of trichloroethylene immediately following the TCE exposure for a 2- to 4-h period. Further research is needed to better understand the biological determinants responsible for the observed variability in urinary excretion of trichloroethanol glucuronide and trichloroacetic acid and the metabolic pathway resulting in formation of dichloroacetic acid.

The role of mouse intestinal microflora in the metabolism of trichloroethylene, an in vivo study

1. Both trichloroethylene and its metabolite, dichloroacetic acid, produce liver tumors peroxisome proliferation and other adverse cellular alterations in rodents. 2. The hepatic mechanism by which dichloroacetic acid is formed is not conclusively demonstrated, but pharmacokinetic models have successfully associated its formation with trichloroacetic acid as immediate precursor. 3. Previous investigations have shown that dichloroacetic acid is formed from trichloroacetic acid by gut microflora isolated in vitro. 4. To determine the impact of gut microflora on dichloroacetic acid formation from a trichloroethylene dose in vivo, we developed a procedure which reduced gut microflora some 3 orders of magnitude below published levels. 5. The administration of trichloroethylene to control mice and to mice whose gut was practically sterile resulted in equivalent concentrations of dichloroacetic acid and other metabolites in blood and liver, but significantly different content of these metabolites in cecum contents. 6. These data indicate that gut microflora contribute minimally, if at all, to the formation of circulating dichloroacetic acid under these conditions.

A physiologically based pharmacokinetic model for trichloroethylene and its metabolites, chloral hydrate, trichloroacetate, dichloroacetate, trichloroethanol, and trichloroethanol glucuronide in B6C3F1 mice

A six-compartment physiologically based pharmacokinetic (PBPK) model for the B6C3F1 mouse was developed for trichloroethylene (TCE) and was linked with five metabolite submodels consisting of four compartments each. The PBPK model for TCE and the metabolite submodels described oral uptake and metabolism of TCE to chloral hydrate (CH). CH was further metabolized to trichloroethanol (TCOH) and trichloroacetic acid (TCA). TCA was excreted in urine and, to a lesser degree, metabolized to dichloroacetic acid (DCA). DCA was further metabolized. The majority of TCOH was glucuronidated (TCOG) and excreted in the urine and feces. TCOH was also excreted in urine or converted back to CH. Partition coefficient (PC) values for TCE were determined by vial equilibrium, and PC values for nonvolatile metabolites were determined by centrifugation. The largest PC values for TCE were the fat/blood (36.4) and the blood/air (15.9) values. Tissue/blood PC values for the water-soluble metabolites were low, with all PC values under 2.0. Mice were given bolus oral doses of 300, 600, 1200, and 2000 mg/kg TCE dissolved in corn oil. At various time points, mice were sacrificed, and blood, liver, lung, fat, and urine were collected and assayed for TCE and metabolites. The 1200 mg/kg dose group was used to calibrate the PBPK model for TCE and its metabolites. Urinary excretion rate constant values were 0. 06/hr/kg for CH, 1.14/hr/kg for TCOH, 32.8/hr/kg for TCOG, and 1. 55/hr/kg for TCA. A fecal excretion rate constant value for TCOG was 4.61/hr/kg. For oral bolus dosing of TCE with 300, 600, and 2000 mg/kg, model predictions of TCE and several metabolites were in general agreement with observations. This PBPK model for TCE and metabolites is the most comprehensive PBPK model constructed for P450-mediated metabolism of TCE in the B6C3F1 mouse.

Electrospray analysis of biological samples for trace amounts of trichloroacetic acid, dichloroacetic acid, and monochloroacetic acid

Trichloroethylene (TCE) has been identified as a widespread groundwater contaminant. Trichloroacetic acid (TCA) and dichloroacetic acid (DCA) are toxicologically relevant metabolites of TCE that produce tumors in B6C3F1 mice. A sensitive method for measuring these metabolites in plasma has been developed to obtain pharmacokinetic data from TCE exposure. This is particularly important because DCA is more potent at producing hepatoproliferative lesions than TCA. At present, it is unclear whether DCA is produced by humans. Existing gas chromatographic methods cannot detect DCA at low nanogram-per-milliliter levels. A Finnigan TSQ 700 mass spectrometer (MS) with electrospray ionization was used to measure TCA, DCA, and monochloroacetic acid (MCA) in plasma. The MS was operated in negative ion tandem MS mode. The limit of detection for TCA and DCA was 4 ng/ml, and the limit of detection for MCA was 25 ng/mL. Plasma samples from human subjects exposed to 100 ppm TCE for 4 h contained TCA at concentrations as high as 10 micrograms/mL. DCA concentrations were less than 5 ng/mL, and MCA was not detected (less than 25 ng/mL).

A physiologically based pharmacokinetic and pharmacodynamic model for paraoxon in rainbow trout

Trout were exposed to an aqueous solution of 75 ng/ml paraoxon for 5 days at 12 degrees C. The relationships among paraoxon concentration in water and target organs, AChE inhibition, and carboxylesterase (CaE) detoxification of paraoxon were characterized quantitatively by development of a PBPK-PD model. The PKPD model structure consisted of brain, heart, liver, kidney, and remainder of the body, which were interconnected by blood circulation. The paraoxon tissue/blood partition coefficients were: plasma/water, 1.46; liver/plasma, 5.89; brain/plasma, 3.90; heart/plasma, 2.91; kidney/plasma, 0.45; and blood/plasma, 0.91. Turnover of AChE was characterized from a dose-response study, in which its zero-order synthesis rate and first-order degradation rate constant were determined in several tissues; for brain they were 7.67 pmol/min and 7.31 x 10(-5) hr(-1). The uptake and depuration clearances of paraoxon (Cl(u) = 0.651 and Cl(d) = 0.468 ml min(-1) g body wt(-1)) were determined using a compartmental model. During continuous water exposure to paraoxon, AChE activity in the tissues declined to new steady state values that were maintained by the synthesis of new AChE. CaE was shown by simulation to be an important pathway for detoxification of paraoxon.

Formation of dichloroacetic acid by rat and mouse gut microflora, an in vitro study

Metabolism of trichloroethylene (TRI) and its major metabolite, trichloroacetic acid (TCA), by gut content and gut microflora cultures was studied to gain an insight into the role of enterohepatic circulation in TRI metabolism. TRI and TCA were incubated anaerobically with rat and mouse cecal contents and TCA was additionally incubated anaerobically and aerobically with microflora cultures from mice. Although TRI was not metabolized by rat or mouse cecal contents. TCA was metabolized to dichloroacetic acid (DCA) by cecal contents. DCA formation in microflora cultures was dependent on initial TCA concentration, duration of incubation, and initial bacterial number. DCA was not observed in aerobic cultures exposed to TCA. These results suggest that strict anaerobic microorganisms of the gut may partly be responsible for dechlorination of TCA to DCA.

Gas chromatographic determination of parathion and paraoxon in fish plasma and tissues

A sensitive capillary gas chromatographic (GC) method for the simultaneous determination of the organophosphate insecticide, parathion, and its active metabolite, paraoxon, in biological samples was developed. This method involved a simple liquid-liquid extraction of parathion and paraoxon from water, plasma, or tissues and capillary GC determination using electron-capture detection and splitless injection; malathion was used as the internal standard. A gradient oven temperature program was used; the injection port and detector temperatures were 200 and 300 degrees C, respectively. These techniques allowed quantitative determination of parathion and paraoxon at 9-210-ng/ml. concentrations;recoveries ranged from 79.4 to 110.3% for tissues and from 91.9 to 100.0% for plasma and water. The within-day and between-day coefficients of variation were less than 8.0%. The method was used to characterize the pharmacokinetics of parathion and paraoxon and the tissue distribution of paraoxon in rainbow trout.

Toxicokinetics of parathion and paraoxon in rainbow trout after intravascular administration and water exposure

Fish are less sensitive than mammals to organophosphate insecticide toxicity. The species differences have been mainly investigated by biochemical studies of AChE and organophosphate interaction. To examine whether species differences in the toxicokinetics of the organophosphate insecticides were also involved in their differential toxicity, rainbow trout were fitted with a dorsal aorta cannula and administered parathion and its active metabolite paraoxon intraarterially (ia) and via water exposure. Serial blood samples were removed and the plasma concentrations of parathion and paraoxon were determined by capillary GC with EC detection. Plasma protein binding was determined by equilibrium dialysis and ultrafiltration. After ia injection the plasma concentration-time profiles of parathion and paraoxon were multiexponential, with a terminal t1/2 of 56.1 and 0.528 hr. The steady-state volumes of distribution and total body clearances (CLb) for parathion and paraoxon were 1370 and 1080 ml kg-1 and 21.4 and 3020 ml hr-1 kg-1; the plasma unbound fractions were 1.23 and 52.5%. The large difference in CLb between parathion and paraoxon appeared to result primarily from differences in plasma protein binding. Parathion had greater persistence in trout than rat, suggesting that sensitivity difference were unrelated to toxicokinetic differences.

Piperidine derivatives: synthesis of potential analgesics in 3-substituted 4-phenylpiperidine series

The syntheses of 1-methyl-3-(3-hydroxy-3-phenylpropyl)-4-phenyl-4-piperidinol and 1-methyl-3(3-hydroxy-3-phenylpropyl)-4-phenyl-4-propanoyloxypiperidine are described. Preliminary pharmacological testing showed these compounds to be weakly active in the writhing test.