Edward O'Mara

Pharmacokinetics of a single dose of the antifungal posaconazole as oral suspension in subjects with hepatic impairment

Abstract Objective: To evaluate posaconazole pharmacokinetics in subjects with different degrees of hepatic impairment compared with matched healthy subjects. Research design and methods: A total of 37 subjects were enrolled in this open-label, single-dose, parallel-group study; 19 with hepatic impairment and 18 healthy subjects with matching demographics. Each subject received a single 400-mg oral dose of posaconazole after a high-fat meal. Blood samples for analysis were taken up to 648 h (∼4 weeks) postdose. Results: Compared with maximum plasma concentration (Cmax) values in matched subjects with normal hepatic function, values were higher among subjects with moderate hepatic impairment (517 vs. 724 ng/mL) but lower among subjects with severe hepatic impairment (608 vs. 403 ng/mL). No clear trend toward increased or decreased exposure was observed with increasingly severe hepatic impairment, and extensive overlap occurred between normal and hepatically impaired subjects. Therefore, pharmacokinetic variables Cmax and area under the curve from time 0 to the time of final quantifiable sample (AUCtf) values were pooled for subjects with hepatic impairment. Pooled Cmax values were similar to the pooled normal groups (607 vs. 605 ng/mL), whereas there was an overall 36% increase in exposure (AUCtf) for the pooled hepatic impairment group compared with the pooled normal group. Posaconazole was well-tolerated, with six (33%) healthy subjects and six (32%) hepatically impaired subjects reporting adverse events. Conclusions: The data from this small single-dose study suggest posaconazole is safe. Furthermore, although limited by the small number of subjects enrolled, the authors feel that dose adjustments are probably not necessary in patients with hepatic impairment; however, physicians should continue to monitor posaconazole use in patients with hepatic impairment.

Pharmacokinetics and Safety Study of Posaconazole Intravenous Solution Administered Peripherally to Healthy Subjects

ABSTRACT This study evaluated the safety, tolerability, and pharmacokinetics of a posaconazole i.v. (intravenous) solution. This was a single-center, 2-part, randomized, rising single- and multiple-dose study in healthy adults. In part 1, subjects received 0 (vehicle), 50, 100, 200, 250, or 300 mg posaconazole in a single dose i.v. by 30-min peripheral infusion (6 cohorts of 12 subjects each [9 active and 3 placebo], making a total of 72 subjects). Blood samples were collected until 168 h postdose. In part 2, subjects were to receive 2 peripheral infusions at a 12-h interval on day 1 followed by once-daily infusion for 9 days. However, part 2 was terminated early because of high rates of infusion site reactions with multiple dosing at the same infusion site. The pharmacokinetics results for part 1 (n = 45 subjects) showed that the mean posaconazole exposure (area under the concentration-time curve from time zero to infinity [AUC0–∞]) ranged from 4,890 to 46,400 ng · h/ml (range of coefficient of variation values, 26 to 50). The dose-proportionality slope estimate (90% confidence interval) for AUC0–∞ was 1.30 (1.19 to 1.41), indicating a greater-than-dose-proportional increase. The data for safety in part 1 show that 29/72 subjects had ≥1 adverse event. Infusion site reactions were reported in 2/9 vehicle subjects, 0/18 placebo subjects, and 7/45 i.v. posaconazole subjects. The data for safety in part 2 show that infusion site reactions were reported in 1/4 (25%) placebo subjects, 3/9 (33%) vehicle control subjects, and 4/5 (80%) i.v. posaconazole (100 mg) subjects (3 posaconazole recipients subsequently developed thrombophlebitis and were discontinued from treatment). In conclusion, the posaconazole i.v. solution showed a greater-than-dose-proportional increase in exposure, primarily at doses below 200 mg. When administered peripherally at the same infusion site, multiple dosing of i.v. posaconazole led to unacceptably high rates of infusion site reactions. Intravenous posaconazole was otherwise well tolerated. Single doses of i.v. posaconazole were tolerated when given through a peripheral vein over 30 min.

Short-term administration of the CCR5 antagonist vicriviroc to patients with HIV and HCV coinfection is safe and tolerable.

Objective:CCR5 antagonists block HIV cell entry through competitive binding to the CCR5 receptor present on the surface of CD4+ cells. The CCR5 receptor is also present on CD8+ cells involved in clearing hepatitis C virus (HCV). The goal of the present study was to examine the short-term safety of a CCR5 antagonist, vicriviroc, in patients with HIV/HCV coinfection. Methods:A randomized, double-blind trial was conducted in 28 HIV/HCV-coinfected subjects with compensated liver disease and plasma HIV RNA below 400 copies/mL. All subjects were receiving a ritonavir-enhanced protease inhibitor regimen, to which vicriviroc (5, 10, or 15 mg/day) or placebo was added for 28 days. Clinical and laboratory evaluations were performed 21 days beyond the treatment period. Results:Treatment with vicriviroc resulted in no clinically meaningful changes in HCV or HIV viral load or any immune parameters. Adverse events were equally distributed among placebo and vicriviroc groups. Transaminase elevations of grade 1 or more were reported as AEs in 1 subject receiving 10-mg vicriviroc and 1 placebo subject. Vicriviroc plasma concentrations were similar to those observed in healthy subjects. Conclusions:Short-term treatment with vicriviroc as part of a ritonavir-containing protease inhibitor-based regimen was safe and well tolerated in HIV/HCV-coinfected subjects. HIV/HCV coinfection also did not affect vicriviroc pharmacokinetics.

Effect of Vicriviroc on the QT/Corrected QT Interval and Central Nervous System in Healthy Subjects

ABSTRACT Vicriviroc is a CCR5 antagonist in clinical development for the treatment of HIV-1. Two phase I studies were conducted to assess the safety of vicriviroc. One study characterized the drugs potential to prolong the QT/corrected QT (QTc) interval and to induce arrhythmia. In this partially blind, parallel-group study, 200 healthy subjects aged 18 to 50 years were randomized in equal groups to the following regimens: (i) placebo for 9 days and a single dose of moxifloxacin at 400 mg on day 10, (ii) placebo, (iii) vicriviroc-ritonavir (30 and 100 mg), (iv) vicriviroc-ritonavir (150 and 100 mg), and (v) ritonavir (100 mg). The second study characterized the effects of a range of vicriviroc doses on the central nervous system (CNS). In this third-party-blind, parallel-group study, 30 healthy subjects aged 18 to 48 years were randomized to receive a single dose of either vicriviroc at 200, 250, or 300 mg or placebo, followed by multiple (seven) once-daily doses of either vicriviroc at 150, 200, or 250 mg or placebo, respectively. In the first study, vicriviroc produced no clinically meaningful effect on the QT/QTc interval when administered at a supratherapeutic or therapeutic dose concurrently with ritonavir. In the second study, vicriviroc produced no observable seizure activity, nor was it held to be associated with any clinically relevant changes in brain waveforms in the final consensus of reviewers. These findings showed that vicriviroc produced no clinically relevant QTc prolongation cardiac or epileptogenic effects in healthy individuals at exposures as high as five times those expected for HIV-infected patients receiving therapeutic doses of vicriviroc in a ritonavir-boosted protease inhibitor-containing regimen.