An Vandebosch

Evaluation of the effect of paliperidone extended release and quetiapine on corrected QT intervals: a randomized, double-blind, placebo-controlled study

The effect of two atypical antipsychotics on QTc intervals (heart rate-corrected QT interval) was evaluated. Patients (N=109) with schizophrenia (79%) or schizoaffective disorder (21%) were randomly assigned in 2 : 2 : 1 ratio to paliperidone extended release (ER), quetiapine, or placebo. Doses of 12 and 18 mg/day of paliperidone ER were compared with quetiapine 800 mg/day. Least-squares mean change from baseline in population-specific linear-derived correction method from baseline to days 6–7 at individual tmax was 5.1 ms less [90% confidence interval: −9.2 to −0.9] with paliperidone ER 12 mg/day than with quetiapine 800 mg/day. On the basis of a prespecified 10-ms noninferiority margin, paliperidone ER was thus declared noninferior to quetiapine (primary analysis). Mean change in population-specific linear-derived correction method from baseline to days 11–12 at individual tmax was 2.3 ms less (90% confidence interval: −6.8 to 2.3) with paliperidone ER 18 mg/day than with quetiapine 800 mg/day. Treatment-emergent adverse events occurred in 36 (82%) patients treated with paliperidone ER, 41 (95%) patients treated with quetiapine, and 14 (64%) patients treated with placebo. No adverse events of a proarrhythmic nature were noted. The effect on the QTc interval in patients with schizophrenia or schizoaffective disorder was comparable between paliperidone ER 12 mg/day (maximum recommended dose), paliperidone ER 18 mg/day (supratherapeutic dose), and quetiapine 800 mg/day.

Acceptability of COL-1492, a vaginal gel, among sex workers in one Asian and three African cities

Objectives: To evaluate the acceptability of COL-1492, a vaginal gel containing 52.5 mg nonoxynol-9, in an HIV prevention trial. Methods: Sex workers participating in a phase II/III triple blind, randomised trial in Benin, Côte d’Ivoire, South Africa, and Thailand were interviewed on the gel’s acceptability at monthly scheduled clinic visits. Safer sex counselling, male condoms, and study gels were given at each monthly visit; a gynaecological examination and HIV test were performed. Phase III interviews considered the participants’ appreciation of the gel. On the first, second, and fifth follow up visits, the study volunteers completed more extensive questionnaires. Results: Responses were similar between treatment arms. Women indicated not liking their gel in 1.8% of the visits; 98.1% of the women found the gel easy to apply; 30.1% said that it affected sexual intercourse. These effects were mostly improvements (92.6%) by facilitating intercourse (73.6%). Intercourse was more often affected in women reporting painful sexual intercourse (OR: 2.59 (95% CI 1.63 to 4.12)) and in older women. The latter effect differed among centres. Conclusion: Most participants found their assigned gel acceptable and the vast majority of reported effects on intercourse were favourable. The type of gel had no significant impact on the findings.

Effect of Hepatic or Renal Impairment on the Pharmacokinetics of Canagliflozin, a Sodium Glucose Co-transporter 2 Inhibitor

PURPOSE Canagliflozin is a sodium-glucose cotransporter 2 inhibitor approved for the treatment of type 2 diabetes mellitus (T2DM). Because T2DM is often associated with renal or hepatic impairment, understanding the effects of these comorbid conditions on the pharmacokinetics of canagliflozin, and further assessing its safety, in these special populations is essential. Two open-label studies evaluated the pharmacokinetics, pharmacodynamics (renal study only), and safety of canagliflozin in participants with hepatic or renal impairment. METHODS Participants in the hepatic study (8 in each group) were categorized based on their Child-Pugh score (normal hepatic function, mild impairment [Child-Pugh score of 5 or 6], and moderate impairment [Child-Pugh score of 7-9]) and received a single oral dose of canagliflozin 300 mg. Participants in the renal study (8 in each group) were categorized based on their creatinine clearance (CLCR) (normal renal function [CLCR ≥80 mL/min]; mild [CLCR 50 to <80 mL/min], moderate [CLCR 30 to <50 mL/min], or severe [CLCR <30 mL/min] renal impairment; and end-stage renal disease [ESRD]) and received a single oral dose of canagliflozin 200 mg; the exception was those with ESRD, who received 1 dose postdialysis and 1 dose predialysis (10 days later). Canagliflozins pharmacokinetics and pharmacodynamics (urinary glucose excretion [UGE] and renal threshold for glucose excretion [RTG]) were assessed at predetermined time points. FINDINGS Mean maximum plasma concentration (Cmax) and area under the plasma concentration-time curve from time zero to infinite (AUC)0-∞ values differed by <11% between the group with normal hepatic function and those with mild and moderate hepatic impairment. In the renal study, the mean Cmax values were 13%, 29%, and 29% higher and the mean AUC0-∞ values were 17%, 63%, and 50% higher in participants with mild, moderate, and severe renal impairment, respectively; values were similar in the ESRD group relative to the group with normal function, however. The amount of UGE declined as renal function decreased, whereas RTG was not suppressed to the same extent in the moderate to severe renal impairment groups (mean RTG, 93-97 mg/dL) compared with the mild impairment and normal function groups (mean RTG, 68-77 mg/dL). IMPLICATIONS Canagliflozins pharmacokinetics were not affected by mild or moderate hepatic impairment. Systemic exposure to canagliflozin increased in the renal impairment groups relative to participants with normal renal function. Pharmacodynamic response to canagliflozin, measured by using UGE and RTG, declined with increasing severity of renal impairment. A single oral dose of canagliflozin was well tolerated by participants in both studies. ClinicalTrials.gov identifiers: NCT01186588 and NCT01759576.

A single-dose, open-label, parallel, randomized, dose-proportionality study of paliperidone after intramuscular injections of paliperidone palmitate in the deltoid or gluteal muscle in patients with schizophrenia.

Paliperidone palmitate (PP) is a long‐acting injectable (LAI) antipsychotic, developed for monthly intramuscular (i.m.) administration into deltoid/gluteal muscle, approved for the treatment of schizophrenia in many countries. To assess the options for i.m. injection sites, dose‐proportionality of PP was investigated after injection of a single dose (25–150 mg eq.) of PP in either gluteal (n = 106) or deltoid (n = 95) muscle of schizophrenic patients. Overall, mean (geometric) area under plasma concentration–time curve from time zero to infinity (AUC∞) of paliperidone increased proportionally with increasing PP doses, regardless of injection site. Mean maximum plasma concentration (Cmax) was slightly less than dose‐proportional for both injection sites at PP doses >50 mg eq. Mean Cmax was higher after injection in the deltoid compared with the gluteal muscle, except for the 100 mg eq. dose, while AUC∞ for both injection sites was comparable at all doses. Median time to reach Cmax (tmax) ranged from 13–14 days after deltoid and 13–17 days after gluteal injection across all doses. Single PP injections in deltoid and gluteal muscles in the dose range of 25–150 mg eq. were generally tolerable both locally and systemically.

Effect of canagliflozin on the pharmacokinetics of glyburide, metformin, and simvastatin in healthy participants

Drug–drug interactions between canagliflozin, a sodium glucose co‐transporter 2 inhibitor, and glyburide, metformin, and simvastatin were evaluated in three phase‐1 studies in healthy participants. In these open‐label, fixed sequence studies, participants received: Study 1‐glyburide 1.25 mg/day (Day 1), canagliflozin 200 mg/day (Days 4–8), canagliflozin with glyburide (Day 9); Study 2‐metformin 2,000 mg/day (Day 1), canagliflozin 300 mg/day (Days 4–7), metformin with canagliflozin (Day 8); Study 3‐simvastatin 40 mg/day (Day 1), canagliflozin 300 mg/day (Days 2–6), simvastatin with canagliflozin (Day 7). Pharmacokinetic parameters were assessed at prespecified intervals. Co‐administration of canagliflozin and glyburide did not affect the overall exposure (maximum plasma concentration [Cmax] and area under the plasma concentration–time curve [AUC]) of glyburide and its metabolites (4‐trans‐hydroxy‐glyburide and 3‐cis‐hydroxy‐glyburide). Canagliflozin did not affect the peak concentration of metformin; however, AUC increased by 20%. Though Cmax and AUC were slightly increased for simvastatin (9% and 12%) and simvastatin acid (26% and 18%) following coadministration with canagliflozin, compared with simvastatin administration alone; however, no effect on active 3‐hydroxy‐3‐methyl‐glutaryl‐CoA (HMG‐CoA) reductase inhibitory activity was observed. There were no serious adverse events or hypoglycemic episodes. No drug–drug interactions were observed between canagliflozin and glyburide, metformin, or simvastatin. All treatments were well‐tolerated in healthy participants.

Effect of carbamazepine on the pharmacokinetics of paliperidone extended‐release tablets at steady‐state

Given the potential concomitant use of carbamazepine and paliperidone extended‐release (ER) in the treatment of schizophrenia or schizoaffective disorder, this open‐label, two‐treatment sequential study investigated the effect of repeated administration of carbamazepine on the steady‐state pharmacokinetics of paliperidone. Sixty‐four patients with a diagnosis of schizophrenia or bipolar‐I disorder received the following treatments in a fixed sequential order, without washout between treatments: (i) paliperidone ER 6 mg tablet once daily for 7 days, and (ii) paliperidone ER 6 mg once daily concomitantly with carbamazepine 200 mg twice daily for the subsequent 21 days. Upon coadministration with carbamazepine, paliperidone steady‐state total exposure (AUC24 h) and peak plasma concentrations (Cmax) decreased by approximately 37% [LSM ratio—AUC24 h: 63.4 (90% CI: 57.19; 70.29); Cmax: 62.47 (90% CI: 55.77; 69.98)]. This decrease is accounted for to a substantial degree by a 35% increase in renal clearance of paliperidone, likely as a result of induction of renal P‐glycoprotein by carbamazepine. A 14% decrease in the amount of drug excreted unchanged in the urine suggests that carbamazepine coadministration has a limited effect on the intestinal absorption or cytochrome metabolism of paliperidone.

Pharmacokinetic profile after multiple deltoid or gluteal intramuscular injections of paliperidone palmitate in patients with schizophrenia

Paliperidone palmitate (PP) is a once‐monthly long‐acting injectable antipsychotic approved for the treatment of schizophrenia in many countries. To evaluate the different injection‐site options, we compared the pharmacokinetic profile of paliperidone after multiple injections of PP 100 mg eq. (156 mg of PP, equivalent to 100 mg of paliperidone) on days 1, 8, 36, and 64 into the deltoid (n = 24) or gluteal muscle (n = 25) in patients with schizophrenia. After four injections in the deltoid muscle, paliperidone exposure was higher for AUCτ and Cmax, compared with the gluteal muscle (geometric mean AUCτ‐based ratio: 120% [90% CI: 93.1–154.7%], and geometric mean Cmax‐based ratio: 130% [90% CI: 100.6–168.9%]). The mean [SD] fluctuation index was higher, with a larger interpatient variability, after deltoid‐injections (75.9% [30.9%]) than gluteal‐injections (58.5% [14.3%]). The median tmax was similar for both sites. PP was generally tolerable in patients, with more favorable local‐site tolerability for gluteal‐injection. In conclusion, to achieve therapeutic‐concentrations quickly, the first‐two injections of PP are best administered into the deltoid muscle, whereas thereafter maintenance‐injections can be administered either in the deltoid or gluteal muscle.

Simulation-guided phase 3 trial design to evaluate vaccine effectiveness to prevent Ebola virus disease infection: Statistical considerations, design rationale, and challenges

Starting in December 2013, West Africa was overwhelmed with the deadliest outbreak of Ebola virus known to date, resulting in more than 27,500 cases and 11,000 deaths. In response to the epidemic, development of a heterologous prime-boost vaccine regimen was accelerated and involved preparation of a phase 3 effectiveness study. While individually randomized controlled trials are widely acknowledged as the gold standard for demonstrating the efficacy of a candidate vaccine, there was considerable debate on the ethical appropriateness of these designs in the context of an epidemic. A suitable phase 3 trial must convincingly ensure unbiased evaluation with sufficient statistical power. In addition, efficient evaluation of a vaccine candidate is required so that an effective vaccine can be immediately disseminated. This manuscript aims to present the statistical and modeling considerations, design rationale and challenges encountered due to the emergent, epidemic setting that led to the selection of a cluster-randomized phase 3 study design under field conditions.