Comparing proton treatment plans of pediatric brain tumors in two pencil beam scanning nozzles with different spot sizes.

Target coverage and organ-at-risk sparing were compared for 22 pediatric patients with primary brain tumors treated using two distinct nozzles in pencil beam scanning (PBS) proton therapy. Consecutive patients treated at our institution using a PBS-dedicated nozzle (DN) were replanned using a universal nozzle (UN) beam model and the original DN plan objectives. Various cranial sites were treated among the patients to prescription doses ranging from 45 to 54 Gy. Organs at risk (OARs) evaluated were patient-dependent; 15 unique OARs were analyzed, all of which were assessed in at least 10 patients. Clinical target volume (CTV) coverage and organ sparing were compared for the two nozzles using dose-volume histogram data. Statistical analysis using a confidence-interval approach demonstrates that CTV coverage is equivalent for UN and DN plans within ± 5% equivalence bounds. In contrast, average mean and maximum doses are significantly higher for nearly all 15 OARs in the UN plans. The average median increase over all OARs and patients is approximately 1.7 Gy, with an increase in the 25%-75% of 1.0-2.3 Gy; the median increase to the pituitary gland, temporal lobes, eyes and cochleas are 1.8, 1.7, 0.7, and 2.7 Gy, respectively. The CTV dose distributions fall off slower for UN than for the DN plans; hence, normal tissue structures in close proximity to CTVs receive higher doses in UN plans than in DN plans. The higher OAR doses in the UN plans are likely due to the larger spot profile in plans created with UN beams. In light of the high rates of toxicities in pediatric patients receiving cranial irradiation and in light of selected brain tumor types having high cure rates, this study suggests the smaller DN beam profile is preferable for the advantage of reducing dose to OARs.

Effect of intranasal esketamine on cognitive functioning in healthy participants: a randomized, double-blind, placebo-controlled study.

BACKGROUND: The effect of intranasal esketamine on cognitive functioning in healthy participants is assessed in this study. METHODS: Twenty-four participants (19-49 years) were randomized to one of two treatment sequences in which either esketamine 84 mg or placebo was intranasally administered in a double-blind, two-period crossover design. Primary measures included five tests of Cogstate® computerized test battery assessed at 1 h predose and 40 min, 2, 4, and 6 h postdose. Secondary measures included the Mental Effort Scale, Karolinska Sleepiness Scale (KSS), and safety. RESULTS: Esketamine was associated with significant cognitive performance impairment at 40 min postdose for all five Cogstate® tests (Detection p = 0.0011, Identification p = 0.0006, One-Card Learning p = 0.0040, One Back p = 0.0017, and Groton Maze Learning Test p < 0.0001) versus placebo. In contrast, performance on these tests did not differ significantly between esketamine and placebo at 2, 4, or 6 h postdose. Secondary outcomes indicated a significant, transient increase from baseline under esketamine versus placebo at 40 min postdose on the Mental Effort Scale and at 40 min and 2 h postdose on KSS (p < 0.0001 for both); however, no significant difference was observed on these outcomes between esketamine and placebo at later timepoints. The most commonly reported adverse events were dizziness (67%), nausea (37.5%), disturbance in attention (29.2%), and fatigue (29.2%); the majority were considered mild in severity. CONCLUSIONS: Esketamine was associated with cognitive performance decline, and greater effort was required to complete the test battery versus placebo at 40 min postdose, which returned to placebo-comparable levels by 2 h postdose. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02094378.

Clinical pharmacokinetics, pharmacodynamics, safety, and tolerability of JNJ-54175446, a brain permeable P2X7 antagonist, in a randomised single-ascending dose study in healthy participants.

BACKGROUND: Central nervous system-derived interleukin-1ß plays a role in mood disorders. P2X7 receptor activation by adenosine-triphosphate leads to the release of interleukin-1ß. AIMS: This first-in-human study evaluated safety, tolerability, pharmacokinetics and pharmacodynamics of a novel central nervous system-penetrant P2X7 receptor antagonist, JNJ-54175446, in healthy participants. METHODS: The study had three parts: an ascending-dose study in fasted participants (0.5-300 mg JNJ-54175446); an ascending-dose study in fed participants (50-600 mg); and a cerebrospinal fluid study (300 mg). Target plasma concentrations were based on estimated plasma effective concentration (EC)50 (105 ng/mL) and EC90 (900 ng/mL) values for central nervous system P2X7 receptor binding. RESULTS: Seventy-seven participants received a single oral dose of JNJ-54175446 ( n=59) or placebo ( n=18). Area under the curve of concentration time extrapolated to infinity (AUC∞) increased dose-proportionally; maximum concentration (Cmax) of plasma (Cmax,plasma) increased less than dose-proportionally following single doses of JNJ-54175446. Because food increases bioavailability of JNJ-54175446, higher doses were given with food to evaluate safety at higher exposures. The highest Cmax,plasma reached (600 mg, fed) was 1475±163 ng/mL. JNJ-54175446 Cmax in cerebrospinal fluid, a proxy for brain penetration, was seven times lower than in total plasma; unbound Cmax,plasma and Cmax,CSF were comparable (88.3±35.7 vs 114±39 ng/mL). JNJ-54175446 inhibited lipopolysaccharide/3'-O-(4-benzoylbenzoyl)-ATP-induced interleukin-1ß release from peripheral blood in a dose-dependent manner (inhibitory concentration (IC)50:82 ng/mL; 95% confidence interval: 48-94). Thirty-three of 59 (55.9%) participants reported at least one treatment-emergent adverse event; the most common adverse event being headache (11/59, 18.6%). CONCLUSION: Plasma exposure of JNJ-54175446 was dose-dependent. No serious adverse events occurred. Single-dose administration of JNJ-54175446>10 mg attenuated ex-vivo lipopolysaccharide-induced interleukin-1ß release in peripheral blood. Passive brain penetration of JNJ-54175446 was confirmed.

Pharmacokinetics of ertapenem in patients with varying degrees of renal insufficiency and in patients on hemodialysis.

Ertapenem is a parenteral beta-lactam carbapenem antibiotic. This open-label study examined the pharmacokinetics of single 1-g intravenous doses of ertapenem, administered over 30 minutes, in patients with mild, moderate, and advanced renal insufficiency (RI) and in patients with end-stage renal disease (ESRD) requiring hemodialysis. Pharmacokinetics were compared with historical controls pooled across healthy young and elderly subjects. Area under the concentration-time curve from time zero to infinity increased 7% in mild, 53% in moderate, 158% in advanced RI, and 192% in ESRD; end of infusion concentration changed minimally; half-life was 4.5 hours in the historical control group and 4.4, 6.1, 10.6, and 14.1 hours in mild RI, moderate RI, advanced RI, and ESRD, respectively. Hemodialysis cleared approximately 30% of the dose. The recommended dose in mild to moderate RI and after hemodialysis is unchanged at 1 g daily; and in advanced RI and ESRD is reduced to 0.5 g daily. If the daily dose is given 6 hours prior to hemodialysis, a supplementary 150-mg dose (30% of the daily dose) is recommended postdialysis.

Intravenous Esketamine in Adult Treatment-Resistant Depression: A Double-Blind, Double-Randomization, Placebo-Controlled Study.

BACKGROUND: The purpose of this study was to assess the efficacy and safety and to explore the dose response of esketamine intravenous (IV) infusion in patients with treatment-resistant depression (TRD). METHODS: This multicenter, randomized, placebo-controlled trial was conducted in 30 patients with TRD. Patients were randomly assigned 1:1:1 to receive an IV infusion of .20 mg/kg or .40 mg/kg esketamine or placebo over 40 minutes on day 1. The primary end point was change in Montgomery-Åsberg Depression Rating Scale total score from day 1 (baseline) to day 2. Nonresponders who received placebo on day 1 were randomly assigned again 1:1 to IV esketamine .20 mg/kg or .40 mg/kg on day 4. Secondary efficacy and safety measures were also evaluated. RESULTS: Of the enrolled patients, 97% (29 of 30) completed the study. The least squares mean changes (SE) from baseline to day 2 in Montgomery-Åsberg Depression Rating Scale total score for the esketamine .20 mg/kg and .40 mg/kg dose groups were -16.8 (3.00) and -16.9 (2.61), respectively, and showed significant improvement (one-sided p = .001 for both groups) compared with placebo (-3.8 [2.97]). Esketamine showed a rapid (within 2 hours) and robust antidepressant effect. Treatment-emergent adverse events were dose dependent. The most common treatment-emergent adverse events were headache, nausea, and dissociation; the last-mentioned was transient and did not persist beyond 4 hours from the start of the esketamine infusion. CONCLUSIONS: A rapid onset of robust antidepressant effects was observed in patients with TRD after a 40-minute IV infusion of either .20 mg/kg or .40 mg/kg of esketamine. The lower dose may allow for better tolerability while maintaining efficacy.

Evaluation of JNJ-26489112 in patients with photosensitive epilepsy: a placebo-controlled, exploratory study.

PURPOSE: To evaluate the activity of JNJ-26489112 in patients with photosensitive epilepsy and determine the doses that result in reduction or complete suppression of the intermittent photic stimulation (IPS) induced photoparoxysmal-EEG response (PPR). METHODS: In this multicenter, single-blind, within subject, placebo-controlled, sequential dose, exploratory study, 12 adult patients (3 men; 9 women) with idiopathic photosensitive epilepsy, with and without concomitant antiepileptic drug (AED) therapy, underwent standardized IPS under three eye conditions (open, during closure, and closed) for up to 12h after receiving a single oral dose of placebo on day 1, JNJ-26489112 on day 2, and a second dose of placebo on day 3. Based on review of the blinded EEG data, the standardized photosensitive range (SPR) (i.e., upper and lower frequencies of the IPS-induced PPR), was calculated for each eye condition at each time point. A positive response was defined as a reduction of the SPR in ≥3 out of 4 consecutive time points in ≥1 eye condition on either day 2 or 3 compared with baseline (day 1) while complete suppression was defined as disappearance of an IPS-induced PPR (i.e., SPR=0). For the first four patients (Cohort 1), JNJ-26489112 dose was 1000 mg, and the dose was escalated to a maximum of 3000 mg in subsequent cohorts. Blood and plasma samples were collected for pharmacokinetic evaluations along with measurements of concurrent AED concentrations. Safety was also assessed. RESULTS: The majority of patients showed a positive response on day 2 following JNJ-26489112 administration: 3/4 patients (1000 mg dose), 3/4 patients (2000 mg dose), and 2/3 patients (3000 mg). There was an apparent dose-dependent effect observed in patients who exhibited complete suppression of the SPR: 0/4 patients (1000 mg dose), 1/4 patient (2000 mg dose), and 2/3 patients (3000 mg dose). The median tmax of JNJ-26489112 (range: 3.73-5.04 h) in plasma was similar across all 3 dose groups and plasma exposure of JNJ-26489112 increased proportionally with dose; approximate mean Cmax of 16, 28, and 42 µg/mL for the 1000-, 2000-, and 3000 mg cohorts, respectively. Concentrations of other AEDs did not appear to be affected by co-administration of JNJ-26489112. JNJ-26489112 was generally well-tolerated with the most frequent adverse events (>10%) reported being mild headache, dizziness, and nausea. CONCLUSION: Single oral doses of JNJ-26489112 were well-tolerated and the pharmacodynamic effects appeared to be dose-related in patients with idiopathic, photosensitive epilepsy.

Modeling the long-term antibody response of a human papillomavirus (HPV) virus-like particle (VLP) type 16 prophylactic vaccine.

The duration over which antibody responses persist following HPV vaccination is unknown. To estimate the longevity of responses induced by HPV-16 vaccination, two models were fitted to serum anti-HPV-16 levels measured during a 48-month study period. The first was a conventional model of antibody decay and the second was a modified model that accounts for long-lived immune memory. Using the antibody decay model, it was estimated that following administration of a three-dose regimen of HPV-16 vaccine in women aged 16-23 years, anti-HPV-16 levels will remain above those induced naturally by HPV-16 infection for 12 years, and above detectable levels for 32 years in 50% of vaccinees. With the modified model, which fitted the data better (p<0.001), it was estimated that near life-long persistence of anti-HPV-16 following vaccination is expected at titer levels above those associated with reduction of natural HPV-16 infection in 76% of these subjects, and above detectable levels in 99% of these subjects.

Disposition of caspofungin: role of distribution in determining pharmacokinetics in plasma.

The disposition of caspofungin, a parenteral antifungal drug, was investigated. Following a single, 1-h, intravenous infusion of 70 mg (200 microCi) of [(3)H]caspofungin to healthy men, plasma, urine, and feces were collected over 27 days in study A (n = 6) and plasma was collected over 26 weeks in study B (n = 7). Supportive data were obtained from a single-dose [(3)H]caspofungin tissue distribution study in rats (n = 3 animals/time point). Over 27 days in humans, 75.4% of radioactivity was recovered in urine (40.7%) and feces (34.4%). A long terminal phase (t(1/2) = 14.6 days) characterized much of the plasma drug profile of radioactivity, which remained quantifiable to 22.3 weeks. Mass balance calculations indicated that radioactivity in tissues peaked at 1.5 to 2 days at approximately 92% of the dose, and the rate of radioactivity excretion peaked at 6 to 7 days. Metabolism and excretion of caspofungin were very slow processes, and very little excretion or biotransformation occurred in the first 24 to 30 h postdose. Most of the area under the concentration-time curve of caspofungin was accounted for during this period, consistent with distribution-controlled clearance. The apparent distribution volume during this period indicated that this distribution process is uptake into tissue cells. Radioactivity was widely distributed in rats, with the highest concentrations in liver, kidney, lung, and spleen. Liver exhibited an extended uptake phase, peaking at 24 h with 35% of total dose in liver. The plasma profile of caspofungin is determined primarily by the rate of distribution of caspofungin from plasma into tissues.