Pharmacokinetic and pharmacodynamic data from the NEOLEV1 and NEOLEV2 studies.

OBJECTIVES: To confirm that levetiracetam (LEV) demonstrates predictable pharmacokinetics(PK) at higher doses and to study the pharmacodynamics(PD) of LEV. DESIGN: Pharmacokinetic data from the NEOLEV1 and NEOLEV2 trials were analysed using a non-linear mixed effects modelling approach. A post hoc analysis of the effect of LEV on seizure burden was conducted. SETTING: Neonatal intensive care unit. PATIENTS: Term neonates with electrographically confirmed seizures. INTERVENTIONS: In NEOLEV1, neonates with seizures persisting following phenobarbital (PHB) received LEV 20 or 40 mg/kg bolus followed by 5 or 10 mg/kg maintenance dose(MD) daily. In NEOLEV2, patients received a 40 mg/kg intravenous LEV load, followed by 10 mg/kg doses 8 hourly. If seizures persisted, a further 20 mg/kg intravenous load was given. If seizures persisted, PHB was given. PK data were collected from 16 NEOLEV1 patients and 33 NEOLEV2 patients. cEEG data from 48 NEOLEV2 patients were analysed to investigate onset of action and seizure burden reduction. MAIN OUTCOME MEASURES: Clearance (CL) and volume of distribution (Vd) were determined. Covariates that significantly affected LEV disposition were identified. RESULTS: Primary outcome: The median initial LEV level was 57 µg/mL (range 19-107) after the first loading dose and at least 12 µg/mL at 48 hours in all infants. CL and Vd were estimated to be 0.0538 L/hour and 0.832 L, respectively. A direct relationship between postnatal age and CL was observed. The final population pharmacokinetic(PopPK) model described the observed data well without significant biases. CL and Vd were described as CL (L/hour)=0.0538×(weight in kg/3.34)0.75×(postnatal age in days/5.5) 0.402 and Vd (L)=0.832×(weight in kg/3.34).Seizure burden reduced within 30 min of LEV administration. 28% of patients were completely seizure free after LEV. In an additional 25% of patients, seizure burden reduced by 50%. CONCLUSIONS: LEV pharmacokinetics remained predictable at higher doses. Very high-dose LEV can now be studied in neonates. TRIAL REGISTRATION NUMBER: NCT01720667.

Analysis of US Food and Drug Administration Oncology Approvals on the Characterization of Hepatic Impairment Effect and Dosing Recommendations.

Patients with cancer and advanced hepatic impairment (HI) (i.e., moderate and severe impairment) are often excluded from first-in-patient, phase II, and phase III studies. Thus, dose recommendations for this subgroup of patients are often derived using a combination of dedicated phase I studies conducted in participants without cancer and a population pharmacokinetic (PK) modeling approach. A standardized risk-based approach to guide the evaluation of HI in patients with cancer is needed. In this review, we evaluated available oncology drug approvals by the US Food and Drug Administration (FDA) from 1999 to 2019, identified strategies utilized by sponsors to characterize the effect of HI on the PK of oncology drugs, and assessed regulatory expectations for each strategy. Finally, we constructed a decision tree that complements current FDA guidance to enable efficient evaluation of the effect of HI on PK and provide guidance for dose recommendations.

Pharmacokinetics of darunavir and cobicistat in pregnant and postpartum women with HIV.

OBJECTIVE: To evaluate darunavir and cobicistat pharmacokinetics during pregnancy compared with postpartum and in infant washout samples after delivery. DESIGN: Nonrandomized, open-label, parallel-group, multicenter phase-IV prospective study of darunavir and cobicistat pharmacokinetics in pregnant women with HIV and their children in the United States. METHODS: Intensive steady-state 24-h pharmacokinetic profiles were performed after administration of 800 mg of darunavir and 150 mg of cobicistat orally in fixed dose combination once-daily during the second trimester, third trimester, and postpartum. Infant washout samples were collected after birth. Darunavir and cobicistat were measured in plasma by validated HPLC-UV and liquid chromatography with tandem mass spectrometry detection (LC-MS)/MS assays, respectively. A two-tailed Wilcoxon signed-rank test (α = 0.10) was employed for paired within-participant comparisons. RESULTS: A total of 29 pregnant women receiving darunavir and cobicistat once-daily enrolled in the study. Compared with paired postpartum data, darunavir AUC0--24 was 53% lower in the second trimester [n = 12, P = 0.0024, geometric mean of ratio (GMR)=0.47, 90% confidence interval (CI) 0.33 - 0.68] and 56% lower in the third trimester (n = 18, P < 0.0001, GMR = 0.44, 90% CI 0.36 - 0.54), whereas cobicistat AUC0--24 was 50% lower in the second trimester (n = 12, P = 0.0024, GMR = 0.50, 90% CI 0.36-0.69) and 56% lower in the third trimester (n = 18, P < 0.0001, GMR = 0.44, 90% CI 0.35-0.55). Placental transfer of darunavir and cobicistat was limited. CONCLUSION: Standard darunavir/cobicistat dosing during pregnancy results in significantly lower exposure during pregnancy, which may increase the risk of virologic failure and perinatal transmission.

Discordance Between Child-Pugh and National Cancer Institute Classifications for Hepatic Dysfunction: Implications on Dosing Recommendations for Oncology Compounds.

Guidance from the U.S. Food and Drug Administration (FDA) and the European Medicines Agency recommends using Child-Pugh classification for pharmacokinetic evaluation in noncancer subjects with hepatic impairment (HI). Therefore, dosing recommendations for oncology compounds for patients with HI are commonly based on Child-Pugh classification. In oncology clinical practice, National Cancer Institute classification (NCIc), is commonly used for evaluating hepatic function and dosing decisions for oncology patients. This work evaluated the discordance between the 2 systems and the impact on dosing recommendations. The classification system in HI studies was reviewed for FDA-approved oncology compounds. Discordance between Child-Pugh and NCIc was evaluated for sunitinib, dacomitinib, palbociclib, bosutinib, and axitinib. Pharmacokinetic (PK) analyses were conducted based on Child-Pugh classification and NCIc. Review of 117 approved oncology compounds showed prevalent use of Child-Pugh classification for dedicated HI studies in noncancer subjects. NCIc is commonly used in cancer patient studies. NCIc tended to classify subjects as less impaired versus Child-Pugh (64.9%, 73.7%, and 61.5% of subjects with mild, moderate, and severe HI, respectively, via Child-Pugh were classified as at least 1 category less impaired via NCIc). PK analyses by NCIc were consistent with Child-Pugh for sunitinib, dacomitinib, and palbociclib. For bosutinib, NCIc showed less impact of HI than Child-Pugh; an opposite trend was observed for axitinib. The impact of this considerable discordance between the 2 systems on dosing decisions bears consideration. When Child-Pugh is used for HI study enrollment, exploratory PK analyses based on NCIc should be conducted. Prescribers should attempt to use the same classification system in the product label for dosing decisions.

Electroencephalography Measures are Useful for Identifying Large Acute Ischemic Stroke in the Emergency Department.

BACKGROUND: Early diagnosis of stroke optimizes reperfusion therapies, but behavioral measures have incomplete accuracy. Electroencephalogram (EEG) has high sensitivity for immediately detecting brain ischemia. This pilot study aimed to evaluate feasibility and utility of EEG for identifying patients with a large acute ischemic stroke during Emergency Department (ED) evaluation, as these data might be useful in the prehospital setting. METHODS: A 3-minute resting EEG was recorded using a dense-array (256-lead) system in patients with suspected acute stroke arriving at the ED of a US Comprehensive Stroke Center. RESULTS: An EEG was recorded in 24 subjects, 14 with acute cerebral ischemia (including 5 with large acute ischemic stroke) and 10 without acute cerebral ischemia. Median time from stroke onset to EEG was 6.6 hours; and from ED arrival to EEG, 1.9 hours. Delta band power (P = .004) and the alpha/delta frequency band ratio (P = .0006) each significantly distinguished patients with large acute ischemic stroke (n = 5) from all other patients with suspected stroke (n = 19), with the best diagnostic utility coming from contralesional hemisphere signals. Larger infarct volume correlated with higher EEG power in the alpha/delta frequency band ratio within both the ipsilesional (r = -0.64, P = .013) and the contralesional (r = -0.78, P = .001) hemispheres. CONCLUSIONS: Within hours of stroke onset, EEG measures (1) identify patients with large acute ischemic stroke and (2) correlate with infarct volume. These results suggest that EEG measures of brain function may be useful to improve diagnosis of large acute ischemic stroke in the ED, findings that might be useful to pre-hospital applications.

Predicting Gains With Visuospatial Training After Stroke Using an EEG Measure of Frontoparietal Circuit Function.

The heterogeneity of stroke prompts the need for predictors of individual treatment response to rehabilitation therapies. We previously studied healthy subjects with EEG and identified a frontoparietal circuit in which activity predicted training-related gains in visuomotor tracking. Here we asked whether activity in this same frontoparietal circuit also predicts training-related gains in visuomotor tracking in patients with chronic hemiparetic stroke. Subjects (n = 12) underwent dense-array EEG recording at rest, then received 8 sessions of visuomotor tracking training delivered via home-based telehealth methods. Subjects showed significant training-related gains in the primary behavioral endpoint, Success Rate score on a standardized test of visuomotor tracking, increasing an average of 24.2 ± 21.9% (p = 0.003). Activity in the circuit of interest, measured as coherence (20-30 Hz) between leads overlying ipsilesional frontal (motor cortex) and parietal lobe, significantly predicted training-related gains in visuomotor tracking change, measured as change in Success Rate score (r = 0.61, p = 0.037), supporting the main study hypothesis. Results were specific to the hypothesized ipsilesional motor-parietal circuit, as coherence within other circuits did not predict training-related gains. Analyses were repeated after removing the four subjects with injury to motor or parietal areas; this increased the strength of the association between activity in the circuit of interest and training-related gains. The current study found that (1) Eight sessions of training can significantly improve performance on a visuomotor task in patients with chronic stroke, (2) this improvement can be realized using home-based telehealth methods, (3) an EEG-based measure of frontoparietal circuit function predicts training-related behavioral gains arising from that circuit, as hypothesized and with specificity, and (4) incorporating measures of both neural function and neural injury improves prediction of stroke rehabilitation therapy effects.

Anhedonia Following Early-Life Adversity Involves Aberrant Interaction of Reward and Anxiety Circuits and Is Reversed by Partial Silencing of Amygdala Corticotropin-Releasing Hormone Gene.

BACKGROUND: Anhedonia, the diminished ability to experience pleasure, is an important dimensional entity linked to depression, schizophrenia, and other emotional disorders, but its origins and mechanisms are poorly understood. We have previously identified anhedonia, manifest as decreased sucrose preference and social play, in adolescent male rats that experienced chronic early-life adversity/stress (CES). Here we probed the molecular, cellular, and circuit processes underlying CES-induced anhedonia and tested them mechanistically. METHODS: We examined functional brain circuits and neuronal populations activated by social play in adolescent CES and control rats. Structural connectivity between stress- and reward-related networks was probed using high-resolution diffusion tensor imaging, and cellular/regional activation was probed using c-Fos. We employed viral-genetic approaches to reduce corticotropin-releasing hormone (Crh) expression in the central nucleus of the amygdala in anhedonic rats, and tested for anhedonia reversal in the same animals. RESULTS: Sucrose preference was reduced in adolescent CES rats. Social play, generally considered an independent measure of pleasure, activated brain regions involved in reward circuitry in both control and CES groups. In CES rats, social play activated Crh-expressing neurons in the central nucleus of the amygdala, typically involved in anxiety/fear, indicating aberrant functional connectivity of pleasure/reward and fear circuits. Diffusion tensor imaging tractography revealed increased structural connectivity of the amygdala to the medial prefrontal cortex in CES rats. Crh-short hairpin RNA, but not control short hairpin RNA, given into the central nucleus of the amygdala reversed CES-induced anhedonia without influencing other emotional measures. CONCLUSIONS: These findings robustly demonstrate aberrant interactions of stress and reward networks after early-life adversity and suggest mechanistic roles for Crh-expressing amygdala neurons in emotional deficits portending major neuropsychiatric disorders.