Anonymous living liver donation: donor profiles and outcomes

There are no published series of the assessment process, profiles and outcomes of anonymous, directed or nondirected live liver donation. The outcomes of 29 consecutive potential anonymous liver donors at our center were assessed. We used our standard live liver assessment process, augmented with the following additional acceptance criteria: a logical rationale for donation, a history of social altruism, strong social supports and a willingness to maintain confidentiality of patient information. Seventeen potential donors were rejected and 12 donors were ultimately accepted (six male, six female). All donors were strongly motivated by a desire and sense of responsibility to help others. Four donations were directed toward recipients who undertook media appeals. The donor operations included five left lateral segmentectomies and seven right hepatectomies. The overall donor morbidity was 40% with one patient having a transient Clavien level 3 complication (a pneumothorax). All donors are currently well. None expressed regret about their decision to donate, and all volunteered the opinion that donation had improved their lives. The standard live liver donor assessment process plus our additional requirements appears to provide a robust assessment process for the selection of anonymous live liver donors. Acceptance of anonymous donors enlarges the donor liver pool.

Chronopharmacology of nebicapone, a new catechol-O-methyltransferase inhibitor

OBJECTIVE

To investigate the chronopharmacology of nebicapone, a new catechol-O-methyltransferase (COMT) inhibitor currently being developed for use as an adjunct to levodopa/carbidopa or levodopa/benserazide in the treatment of Parkinson's disease.

METHODS

This was a double-blind, randomised, placebo-controlled, parallel-group study. Eighteen Caucasian subjects were randomly assigned to treatment with either nebicapone 100 mg (n = 6), nebicapone 200 mg (n = 6) or placebo (n = 6) at 4-h intervals for 7 days. First dose occurred at 8:00 AM on day 1 and last dose at 8:00 AM on day 8. Blood samples for the determination of plasma drug concentrations of nebicapone and its glucuronidated and methylated metabolites and for the assay of erythrocyte soluble COMT (S-COMT) activity were taken at frequent times following the first and last doses, and before the 8:00 AM and 8:00 PM doses on days 2-7.

RESULTS

Three men and three women in each group participated in the study. Mean +/- SD (range) age of study participants was 23.7 +/- 3.1 (21-28) years in the nebicapone 100 mg group, 22.2 +/- 0.4 (22-23) years in the nebicapone 200 mg group and 24.3 +/- 5.4 (18-32) in the placebo group. A circadian variation in the pre-dose nebicapone and nebicapone-glucuronide plasma concentrations was apparent. Both nebicapone and nebicapone-glucuronide levels were lower before the 8 PM dose in comparison to the 8 AM dose, suggesting that the absorption of nebicapone may follow a circadian variation. S-COMT activity showed no circadian variation in the placebo group. Therefore, the S-COMT activity variation found in nebicapone-treated subjects is considered to be due to changes in plasma concentrations of nebicapone, which is consistent with the fact that the pre-dose S-COMT activity was lower at the time at which nebicapone levels were maximal. Four subjects in the nebicapone 100 mg and placebo groups and six subjects in the nebicapone 200 mg group reported at least one adverse event (AE). All AEs were of mild or moderate intensity. Both nebicapone treatment regimens were subjectively well-tolerated, but a clinically relevant elevation in aspartate transaminase was observed in one subject of each nebicapone group.

CONCLUSION

Nebicapone showed chronopharmacology in young Caucasian healthy subjects. The clinical impact of the circadian variation in the nebicapone metabolism and activity in Parkinson's disease patients deserves evaluation as it may have implications for drug prescription by modulating the distribution of the total daily dose along the 24-h scale.

Species differences in pharmacokinetic and pharmacodynamic properties of nebicapone

The present study was designed to characterize pharmacodynamic and pharmacokinetic properties of nebicapone in rats and mice. Upon oral administration of nebicapone the extent of mouse liver catechol-O-methyltransferase (COMT) inhibition is half that in the rat. Nebicapone was rapidly absorbed reaching plasma C(max) within 30min and being completely eliminated by 8h. Nebicapone was metabolized mainly by glucuronidation and methylation in both species, but rat had an extra major metabolite, resulting from sulphation. Administration of nebicapone by the intraperitoneal route significantly increased compound AUC in the rat while in the mouse a significant increase in AUC of metabolites was observed. These results show that nebicapone exhibited marked species differences in bioavailability and metabolic profile. Evaluation of COMT activity in rat and mice liver homogenates revealed that both had similar methylation efficiencies (K(cat) values, respectively 7.3 and 6.4min(-1)), but rat had twice active enzyme units as the mouse (molar equivalency respectively 150 and 83). Furthermore, nebicapone inhibited rat liver COMT with a lower K(i) than mouse liver COMT (respectively 0.2nM vs. 1.2nM). In conclusion, the results from the present study show that mice and rats respond differently to COMT inhibition by nebicapone. The more pronounced inhibitory effects of nebicapone in the rat may be related to an enhanced oral availability and less pronounced metabolism of nebicapone in this specie, but also concerned with the predominant expression of S-COMT over MB-COMT, the latter of which is less sensitive to inhibition by nebicapone than the former.

Effect of simvastatin on the pharmacokinetics of anastrozole

1517

Background: When used in the adjuvant setting, aromatase inhibitors (AIs) reduce the incidence of contralateral breast cancer and are therefore under investigation for primary breast cancer prevention. Statins hold promise for chemoprevention based on preclinical and epidemiological data. Adding statin to AI has the potential to enhance breast cancer prevention and to protect women from AI-related side effects. Prior to initiating a chemoprevention trial of combination therapy, we evaluated the potential for pharmacokinetic drug-drug interaction between anastrozole and simvastatin in postmenopausal women taking adjuvant anastrozole to ensure that the combination will not influence anastrozole concentration or affect its ability to reduce estrogen. Methods: Postmenopausal women with hormone receptor-positive, stage 0-III breast cancer who had been on adjuvant anastrozole (1 mg/day) for at least 30 days were prescribed 14 days of simvastatin (40 mg/day). We collected serum at baseline (anastrozole alone) and after 14 days of simvastatin initiation (combination therapy). Anastrozole and hydroxyanastrozole, its hydroxylated metabolite, concentrations were determined using liquid chromatography-tandem mass spectrometry assay. Estrogen concentrations will be determined using radio-immunoassay. Significant change in anastrozole was predetermined to be greater than a 30% decrease in concentrations. Percent changes from baseline in anastrozole and hydroxyanastrozole were evaluated using Wilcoxon signed-rank tests. Results: From December 2006 to September 2008, 11 women (10 Caucasian, 1 Black, all reported non-Hispanic with a mean age of 60 yrs [range 51–69]) were enrolled in the study. Of these women, nine had evaluable anastrozole concentrations. After 14 days of simvastatin, there were nonsignificant changes in anastrozole (median percentage difference = 10.1% [-13.5%, 38.4%], p = 0.36) and hydroxyanastrozole (median percentage difference = -3.0% [-19.1%, 11.2%], p = 0.65). Estrogen data will be available for presentation. Conclusions: Simvastatin is unlikely to alter the pharmacokinetics of anastrozole in a clinically meaningful way. Combination studies to assess chemopreventive properties of the combination are planned.

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Updated analysis of a phase II study (20060314) of panitumumab (pmab) with FOLFIRI as first-line treatment of patients (pts) with metastatic colorectal cancer (mCRC)

4085

Background: The fully human anti-epidermal growth factor receptor monoclonal antibody pmab, has proven monotherapy activity in chemotherapy refractory mCRC pts with wild-type KRAS-expressing tumors. This first-line, single-arm phase II study is prospectively evaluating whether KRAS status predicts response to treatment when pmab is combined with FOLFIRI. Methods: In this ongoing study, pts with histologically confirmed mCRC (no prior systemic treatment) and ECOG PS 0–2 were enrolled at 36 sites across Europe. Pmab (6mg/kg) and FOLFIRI are administered every 2 weeks. The primary endpoint is objective response rate; secondary endpoints include disease control rate, duration of response, time to response, progression-free survival, time to progression and safety. Results: Data cut-off for the initial interim analysis was 27 June 08 and pending approval of protocol amendment 2, the cut off date for 16 week response rate is 15 Oct 08. Of the 154 pts enrolled, 68% are male; median age is 64 yrs (range, 21–84) and the majority (95%) of pts had ECOG PS 0–1. All pts have received at least one cycle of study treatment; 18% of pts have received ≤2 cycles of full combination therapy and the median number of cycles received is 6. At time of data cut-off, 112 patients (73%) were still receiving at least one element of combination therapy and 29% had stopped treatment with pmab. The most common reason for discontinuing treatment was disease progression (10%). Median follow-up time was 14.3 weeks for all enrolled pts. A total of 97% of patients had experienced at least one adverse event (any grade) and 55% of patients had experienced a grade 3/4 adverse event. There were four reported grade 5 events (hematemesis, rectal hemorrhage, vena cava thrombosis, general physical health deterioration). At time of interim analysis, tissue samples for KRAS analysis are available for approximately 80% of patients. Conclusions: Combining pmab with FOLFIRI in the first-line setting appears to be a well-tolerated regimen. Response rate at 16 weeks in the overall population and by KRAS status and updated safety will be presented.

[Table: see text]

Epidermal growth factor receptor (EGFR) inhibitor–related skin toxicity: Review of interim data from a phase II study (20060314) of panitumumab (pmab) with FOLFIRI in the first-line treatment of metastatic colorectal cancer (mCRC)

e20634

Background: Skin toxicity that can impact quality of life as well as treatment adherence is commonly associated with EGFR therapy. Despite their particular importance in terms of making decisions regarding supportive care, time to onset and maximum grade of skin toxicity are seldom reported. Pmab is a fully human monoclonal antibody directed against the EGFR with demonstrated monotherapy activity in patients (pts) with wild-type KRAS expressing, chemotherapy refractory, mCRC. Methods: In this single-arm study, first-line pts with histologically confirmed mCRC were enrolled to receive pmab (6mg/kg) and FOLFIRI every 2 weeks. This trial is ongoing to evaluate the primary endpoint of objective response rate and secondary endpoints including disease control rate, duration of response, time to response, progression-free survival, time to progression and other safety aspects. The focus of this abstract is skin toxicity. Results: Cutoff for the initial interim analysis was 27 June 2008. Of the 154 pts enrolled, 68% are male; median age is 64 years (range 21–84) and 95% of pts had ECOG PS 0–1. A total of 97% of pts had experienced at least one adverse event (any grade) and 55% of pts had experienced a grade 3/4 event. Grade 3/4 skin and subcutaneous toxicities were observed in 20% of pts ( Table ). Median time to first cutaneous toxicity and median time to most severe toxicity were 9 (95%CI, 7–13) and 14 (95%CI, 13–16) days, respectively. The most severe toxicity was grade 4 in one pt. Conclusions: Combining pmab with FOLFIRI in the first-line setting is a well-tolerated regimen. Skin toxicity was observed in 92% of patients; onset, incidence, and severity of which appears to be comparable to published data. Management of skin toxicities will be presented.

[Table: see text]

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Pharmacokinetic-pharmacodynamic interaction between nebicapone, a novel catechol-o-methyltransferase inhibitor, and controlled-release levodopa/carbidopa 200 mg/50 mg : randomized, double-blind, placebo-controlled, crossover study in healthy subjects

BACKGROUND AND OBJECTIVES

Levodopa is the most effective symptomatic treatment for Parkinson's disease (PD), but its use is often associated with development of motor complications. These adverse responses to fluctuations in dopaminergic stimulation can be reduced by concomitant administration of a catechol-O-methyltransferase (COMT) inhibitor. Nebicapone is a new COMT inhibitor currently being developed for use as an adjunct to levodopa/dopa decarboxylase inhibitor in the treatment of PD. This article aimed to investigate the effect of single oral doses (50 mg, 100 mg and 200 mg) of nebicapone on levodopa pharmacokinetics and erythrocyte-soluble COMT (S-COMT) activity when coadministered with a single dose of controlled-release (CR) levodopa/carbidopa 200 mg/50 mg (Sinemet((R)) CR 200/50) in healthy subjects (n = 16).

METHODS

This was a randomized, double-blind, placebo-controlled, four-way crossover study in healthy subjects, with at least 5 days of washout between treatment periods.

RESULTS

There was a dose-dependent and significant increase in levodopa extent of exposure (area under the plasma concentration-time curve from time zero to infinity [AUC(infinity)]) without a significant change in peak exposure (maximum plasma concentration; [C(max)]). Using placebo as a reference, levodopa geometric mean ratios (GMRs) and 90% CIs following nebicapone 50 mg, 100 mg and 200 mg were, respectively, 1.13 (0.98, 1.30), 1.04 (0.90, 1.19) and 1.10 (0.96, 1.27) for C(max) and 1.26 (1.16, 1.34), 1.37 (1.27, 1.75) and 1.47 (1.42, 1.65) for AUC(infinity). For 3-O-methyldopa (3-OMD), the GMRs and 90% CIs were, respectively, 0.61 (0.55, 0.67), 0.45 (0.41, 0.50) and 0.33 (0.30, 0.36) for C(max) and 0.69 (0.61, 0.78), 0.53 (0.41, 0.61) and 0.41 (0.37, 0.47) for AUC(infinity). Nebicapone dose dependently and significantly decreased COMT activity. Maximum COMT inhibition occurred at 1.5-2.4 hours post-dose and ranged from 56% to 73% with nebicapone 50 mg and 200 mg, respectively. There was a good correlation between plasma concentrations of nebicapone and inhibition of S-COMT activity. Treatments were well tolerated.

CONCLUSION

Following concomitant administration with levodopa/carbidopa CR 200 mg/50 mg, single doses of nebicapone 50 mg, 100 mg and 200 mg significantly and dose-dependently inhibited S-COMT activity, increased systemic exposure to levodopa, and reduced 3-OMD formation.

Rapid and sensitive detection of Avibacterium paragallinarum in the presence of other bacteria using a 5' Taq nuclease assay: a new tool for diagnosing infectious coryza

A 5' Taq nuclease assay specific for Avibacterium paragallinarum was designed and optimized for use in diagnosing infectious coryza. The region chosen for assay design was one of known specificity for Av. paragallinarum. The assay detected Av. paragallinarum reference strains representing the three Page and the eight Kume serovars, and field isolates from diverse geographical locations. No cross-reactions were observed with other Avibacterium species, with other bacteria taxonomically related to Av. paragallinarum nor with bacteria and viruses likely to be present in swabs collected from suspected infectious coryza cases. The detection limit for the assay was 6 to 60 colony-forming units per reaction. Twenty-two out of 53 swabs collected from sick birds reacted in the 5' Taq nuclease assay, whereas Av. paragallinarum was not isolated from any of the swabs. All of the 22 swabs yielded other bacteria in culture. The presence of Av. paragallinarum in the swabs was also demonstrated by sequencing, thereby confirming the ability of the assay to detect Av. paragallinarum in the presence of other bacteria. The ability to quantify bacterial load in the swabs using the 5' Taq nuclease assay was demonstrated.