Safety and pharmacokinetics of ONC201 (dordaviprone) administered two consecutive days per week in pediatric patients with H3K27M-mutant glioma.

BACKGROUND: This study evaluated the safety and pharmacokinetics (PK) of oral ONC201 administered twice-weekly on consecutive days (D1D2) in pediatric patients with newly diagnosed DIPG and/or recurrent/refractory H3 K27M glioma. METHODS: This phase 1 dose-escalation and expansion study included pediatric patients with H3 K27M-mutant glioma and/or DIPG following ≥1 line of therapy (NCT03416530). ONC201 was administered D1D2 at three dose levels (DLs; -1, 1, and 2). Actual administered dose within DLs was dependent on weight. Safety was assessed in all DLs; PK analysis was conducted in DL2. Patients receiving once-weekly ONC201 (D1) served as a PK comparator.1. RESULTS: Twelve patients received D1D2 ONC201 (DL-1, n=3; DL1, n=3; DL2, n=6); no dose-limiting toxicities or grade ≥3 treatment-related adverse events occurred. PK analyses at DL2 (D1-250mg, n=3; D1-625mg, n=3; D1D2-250mg, n=2; D1D2-625mg, n=2) demonstrated variability in Cmax, AUC0-24, and AUC0-48, with comparable exposures across weight groups. No accumulation occurred with D1D2 dosing; the majority of ONC201 cleared before administration of the second dose. Cmax was variable between groups but did not appear to increase with D1D2 dosing. AUC0-48 was greater with D1D2 than once-weekly. CONCLUSIONS: ONC201 given D1D2 was well-tolerated at all DLs and associated with greater AUC0-48.

Utility of Cytochrome P450 4F2 Genotyping to Assess Drug Interaction Risk for Brincidovovir, a Cytochrome P450 4F2 Substrate.

Smallpox was eradicated in 1980 but remains a biothreat due to the potential release of variola virus into the general population. Brincidofovir, the second medicine approved by the US Food and Drug Administration to treat smallpox, is metabolized by oxidative and hydrolytic pathways. The oxidative pathway is initiated by cytochrome P450 4F2 (CYP4F2), an enzyme lacking clinical probes for drug interaction studies. The aim of this work was to assess the impact of reduced activity CYP4F2 variants (rs2108622, C/T and T/T) on brincidofovir pharmacokinetics as a surrogate for drug inhibition. Genotyping was performed on blood from healthy participants receiving oral (n = 261) and intravenous (IV, n = 49) brincidofovir across 6 phase 1 trials. Plasma concentrations were measured by validated liquid chromatography tandem mass spectrometry methods. After oral administration, subjects with the lowest activity CYP4F2 genotype (T/T) had up to 36% higher AUCinf and 29% higher Cmax while subjects with the moderate activity CYP4F2 genotype (C/T) had similar Cmax and AUCinf compared to those with the wild-type genotype. Little to no increase in brincidofovir exposure parameters was observed following IV administration. Based on the lack of significant increases in brincidofovir plasma concentrations in subjects with low activity CYP4F2, a clinically meaningful drug-drug interaction is not expected with CYP4F2 inhibitor and brincidofovir coadministration.

Pharmacokinetics of Coadministered Viloxazine Extended-Release (SPN-812) and Lisdexamfetamine in Healthy Adults.

BACKGROUND: Viloxazine extended-release is a novel nonstimulant under investigation as a potential treatment for attention-deficit/hyperactivity disorder (ADHD). Given the potential for viloxazine extended-release to be co-administered with stimulant ADHD pharmacotherapies, this trial investigated the pharmacokinetics and safety of combination viloxazine extended-release + lisdexamfetamine dimesylate (lisdexamfetamine) versus viloxazine extended-release and lisdexamfetamine alone. METHODS: In this single-center, cross-over, open-label trial, healthy, non-ADHD adults received single oral doses of 700 mg viloxazine extended-release alone, 50 mg lisdexamfetamine alone, and a combination of viloxazine extended-release (700 mg) + lisdexamfetamine (50 mg), with blood samples collected over 4 days postadministration. The active drug in viloxazine extended-release (viloxazine) and primary metabolite of lisdexamfetamine (d-amphetamine) were measured using chromatographic tandem mass spectrometry. Safety assessments included adverse events, vital signs, echocardiograms, and clinical laboratory evaluations. RESULTS: Thirty-six adults were enrolled, and 34 completed the trial. The least squares geometric mean ratios are reported as [combination / single drug (90% confidence intervals)]. Viloxazine extended-release: Cmax = 95.96% (91.33-100.82), area under the concentration-time curve from 0 to the last measurable time (AUC0-t) = 99.19% (96.53-101.91), and area under the concentration-time curve from 0 to infinity (AUCinf) = 99.23% (96.61-101.93). Lisdexamfetamine: Cmax = 112.78% (109.93-115.71), AUC0-t = 109.64% (105.25-114.22), and AUCinf = 109.52% (105.19-114.03). All reported adverse events, except 1 (moderate vomiting), were mild in severity. CONCLUSIONS: Co-administration of viloxazine extended-release and lisdexamfetamine did not impact the pharmacokinetics of viloxazine or d-amphetamine relative to administration of either drug alone. After single dose administration, the combination appeared to be safe and well tolerated.

Pharmacokinetics of Coadministered Viloxazine Extended-Release (SPN-812) and Methylphenidate in Healthy Adults.

BACKGROUND AND OBJECTIVES: Viloxazine extended-release (viloxazine ER, SPN-812) is a novel non-stimulant with activity at serotonin receptors and the norepinephrine transporter, which is under investigation as a potential treatment for attention-deficit/hyperactivity disorder. Given the potential for viloxazine ER to be coadministered with other pharmacotherapies, this trial investigated the pharmacokinetics and safety of combination viloxazine ER + methylphenidate versus viloxazine ER or methylphenidate alone. METHODS: In this single-center, crossover, open-label trial, healthy adult participants received oral administration of 700 mg viloxazine ER alone, 36 mg methylphenidate alone, and combination viloxazine ER (700 mg) + methylphenidate (36 mg), with blood samples collected over 4 days post-administration. The active drug in viloxazine ER (viloxazine) and methylphenidate was measured using chromatographic tandem mass spectrometry. Safety assessments included adverse events (AEs), vital signs, echocardiograms, and clinical laboratory evaluations. RESULTS: Of 36 healthy adults who were enrolled, 34 completed the trial. The geometric least squares mean ratios are reported as [combination/single drug (90% confidence intervals)]. For viloxazine ER, maximum measured plasma concentration (Cmax) = 100.98% (96.21-105.99), area under the concentration-time curve from time zero to the last measurable time (AUCt) = 98.62% (96.21-101.08), and area under the concentration-time curve from time zero to infinity (AUC∞) = 98.96% (96.55-101.44). For methylphenidate, Cmax = 103.55% (97.42-110.07), AUCt = 106.67% (101.01-112.64), and AUC∞ = 106.61% (100.99-112.54). All reported AEs were mild in severity. CONCLUSIONS: Coadministration of viloxazine ER and methylphenidate did not impact the pharmacokinetics of viloxazine or methylphenidate relative to administration of either drug alone. The combination appeared to be safe and well tolerated.

Predicted Efficacy of Once-Daily Extended-Release Oxcarbazepine (Oxtellar XR®) Monotherapy in Adults and Children with Partial-Onset Seizures: Exposure-Response Modeling and Simulation.

PURPOSE: We conducted exposure-response modeling and simulations to compare the predicted efficacy of extended-release oxcarbazepine (OXC-XR), an oral once-daily (qd) antiepileptic drug, with that of immediate-release (IR) OXC twice-daily (bid) when the agents are used as monotherapy or adjunctive therapy in patients with epilepsy characterized by partial-onset seizures (POS). METHODS: Modeling assessed percent change from baseline 28-day seizure frequency (PCH) as a function of minimum concentration (Cmin) of monohydroxy derivative (MHD), the clinically relevant metabolite of OXC. For OXC-IR, the model used historical data; values for OXC-XR were derived from observed data. The model was simulated (N=100) to predict PCH at MHD Cmin concentrations achieved with 1200 and 2400 mg/day in adults and children receiving OXC-XR qd or OXC-IR bid. Mean PCH and 95% confidence intervals (CIs) were generated and compared. RESULTS: Predicted efficacy was not different (ie, 95% CI of mean PCH overlapped) for OXC-XR qd vs OXC-IR bid at mean MHD Cmin concentrations achieved with 1200 and 2400 mg/day adjunctive OXC-XR (47.4 and 76.4 µmol/L) and at target MHD Cmin concentrations for OXC-IR monotherapy (59.1 and 112 µmol/L) in adults. Predicted efficacy in adults vs children was not different between formulations. Depending on MHD Cmin, the predicted mean PCH in adults ranged from -51.4% to -73.4% with OXC-XR qd and -53.2% to -78.5% with OXC-IR bid. In children, the predicted mean PCH ranged from -48.4% to -58.1% (OXC-XR qd) and -32.5% to -70.4% (OXC-IR bid). CONCLUSION: This model-based analysis predicted comparable efficacy for OXC-XR qd vs OXC-IR bid at MHD Cmin concentrations corresponding to 1200 and 2400 mg/day as monotherapy or adjunctive therapy. Based on this analysis, the US Food & Drug Administration approved OXC-XR for use as monotherapy in adults and children ≥6 years of age with POS.

Evaluation of the Effect of SPN-812 (Viloxazine Extended-Release) on QTc Interval in Healthy Adults.

OBJECTIVE: To assess the effects of a supratherapeutic dose of SPN-812, a drug currently under investigation as a treatment for attention-deficit/hyperactivity disorder, on cardiac repolarization (QTc) in healthy adults. METHODS: The study was conducted from June 27, 2018, to July 10, 2018. It had a double-blind, randomized, crossover design in which subjects received a 3-treatment sequence-placebo, 400 mg moxifloxacin, and 1,800 mg SPN-812 for 2 consecutive days (separated by at least a 3-day washout). The primary endpoint was the correlation between the change from baseline (CFB) in individual heart rate corrected QT interval (QTcI) (ΔQTcI) and viloxazine and 5-hydroxyviloxazine glucuronide (5-OH-VLX-gluc) plasma concentrations (Cps). The secondary endpoint was the time point placebo-adjusted CFB in QTcI (ΔΔQTcI) for viloxazine. For assay sensitivity, the correlations between moxifloxacin Cp and the ΔQTcI, and moxifloxacin and time point ΔΔQTcI were evaluated. Additional evaluations included Fridericia's formula QT correction, heart rate, and the PR and QRS intervals. Changes in electrocardiogram (ECG) morphology along with other safety parameters were also analyzed and reported. RESULTS: The correlation between ΔQTcI and viloxazine Cp demonstrated a statistically significant negative slope (P = .0012). 5-OH-VLX-gluc Cp and ΔQTcI also demonstrated a statistically significant negative slope (P = .0007). Secondary time point analyses showed no effect of SPN-812 on QTcI. Assay sensitivity with moxifloxacin was confirmed. Safety parameters were acceptable. CONCLUSIONS: This study demonstrated that SPN-812 had no effect on cardiac repolarization or other ECG parameters in healthy adults, suggesting that it is not associated with a risk for cardiac arrhythmias or other electrocardiographic parameters.

l-tetrahydropalmatine reduces nicotine self-administration and reinstatement in rats.

BACKGROUND: The negative consequences of nicotine use are well known and documented, however, abstaining from nicotine use and achieving abstinence poses a major challenge for the majority of nicotine users trying to quit. l-Tetrahydropalmatine (l-THP), a compound extracted from the Chinese herb Corydalis, displayed utility in the treatment of cocaine and heroin addiction via reduction of drug-intake and relapse. The present study examined the effects of l-THP on abuse-related effects of nicotine. METHODS: Self-administration and reinstatement testing was conducted. Rats trained to self-administer nicotine (0.03 mg/kg/injection) under a fixed-ratio 5 schedule (FR5) of reinforcement were pretreated with l-THP (3 or 5 mg/kg), varenicline (1 mg/kg), bupropion (40 mg/kg), or saline before daily 2-h sessions. Locomotor, food, and microdialysis assays were also conducted in separate rats. RESULTS: l-THP significantly reduced nicotine self-administration (SA). l-THP's effect was more pronounced than the effect of varenicline and similar to the effect of bupropion. In reinstatement testing, animals were pretreated with the same compounds, challenged with nicotine (0.3 mg/kg, s.c.), and reintroduced to pre-extinction conditions. l-THP blocked reinstatement of nicotine seeking more effectively than either varenicline or bupropion. Locomotor data revealed that therapeutic doses of l-THP had no inhibitory effects on ambulatory ability and that l-THP (3 and 5 mg/kg) significantly blocked nicotine induced hyperactivity when administered before nicotine. In in-vivo microdialysis experiments, l-THP, varenicline, and bupropion alone elevated extracellular dopamine (DA) levels in the nucleus accumbens shell (nAcb). CONCLUSIONS: Since l-THP reduces nicotine taking and blocks relapse it could be a useful alternative to varenicline and bupropion as a treatment for nicotine addiction.