Simultaneous Quantification of 17 Cannabinoids bY LC-MS-MS in Human Plasma

BACKGROUND

In recent years, the surge in use and of clinical trials involving tetrahydrocannabinol (THC) and cannabidiol (CBD) has increased the need for sensitive and specific analytical assays to measure said compounds in patients, to establish dose-effect relationships and to gain knowledge of their pharmacokinetics and metabolism. We developed and validated an online extraction high-performance liquid chromatography- tandem mass spectrometry (LC-MS/MS) method for simultaneous quantification of 17 cannabinoids and metabolites including THC and its metabolites, CBD and its metabolites and other minor cannabinoids in human plasma.

METHODS

CBD-glucuronide (CBD-gluc) standard was produced in-house by isolation of CBD-gluc from urine of patients using pure CBD oil. For calibration standards and quality control samples, human plasma was spiked with cannabinoids at varying concentrations within the working range of the respective compound and 200 µL was extracted using a simple one-step protein precipitation procedure. The extracts were analyzed using online trapping LC/LC-atmospheric pressure chemical ionization (APCI)-MS/MS running in the positive multiple reaction monitoring (MRM) mode.

RESULTS

The lower limit of quantification ranged from 0.78 ng/mL to 7.8 ng/mL and the upper limits of quantification were between 100 ng/mL and 2000 ng/mL. Inter-day analytical accuracy and imprecision ranged from 90.4 to 111% and from 3.1 to 17.4%, respectively. The analysis of plasma samples collected during clinical studies showed that (3R-trans)-Cannabidiol-7-oic Acid (7-CBD-COOH) was the major human metabolite with 5960% of CBD followed by 7-hydroxy-CBD (177%), CBD-gluc (157%) and 6α-hydroxy-CBD (39.8%); 6β-hydroxy-CBD was not detected in any of the samples.

CONCLUSIONS

In the present study, we developed and validated a robust LC-MS/MS assay for the simultaneous quantification of cannabinoids and their metabolites, which has been used to measure >5,000 samples in clinical studies. Moreover, we were able to quantify CBD-gluc and showed that 7-CBD-COOH, 7-hydroxy-CBD and CBD-gluc are the major CBD metabolites in human plasma.

Nonseizure consequences of Dravet syndrome, KCNQ2-DEE, KCNB1-DEE, Lennox-Gastaut syndrome, ESES: A functional framework

RATIONALE

Developmental epilepsies and encephalopathies (DEEs) are characterized by many severe developmental impairments, which are not well-described. A functional framework could facilitate understanding of their nature and severity and guide the selection instruments to measure improvements in therapeutic trials.

METHODS

An online survey administered through several parent-organized foundations utilized accepted functional classifications and questionnaires derived from common instruments to determine levels of mobility, fine motor, communication, and feeding functions. Statistical analyses focused on overall levels of function and across-group comparisons adjusted for age.

RESULTS

From 6/2018 to 2/2020, 252 parents provided information for one or more functional domains. Median age was 7.2 years (interquartile range (IQR): 3.9 to 11.8), and 128 (51%) were females. DEE groups were Dravet syndrome (N = 72), KCNQ2-DEE (N = 80), KCNB1-DEE, (N = 33), Lennox-Gastaut syndrome (LGS; N = 26), electrographic status epilepticus in sleep (ESES; N = 15), and others (N = 26). Overall, functional hand grasp was absent in 48 (20%). Of children ≥2 years old, 60/214 (28%) could not walk independently, 85 (40%) were dependent on someone else for feeding, and 153 (73%) did not effectively communicate with unfamiliar people. Impairments entailing absence or near absence of independent function (profound impairment) were observed in 0, 1, 2, 3, and 4 domains for 58 (25%), 78 (34%), 40 (17%), 33 (14%), and 22 (10%) children, respectively. After adjustment for age, impairment levels varied substantially across DEE group for mobility (p < 0.0001), feeding (p < 0.0001), communication (p < 0.0001), hand grasp (p < 0.0001), and number of profoundly impaired domains (p < 0.0001). Three or four profoundly affected domains were reported in 44% of KCNQ2-DEE participants, followed by LGS (29%), KCNB1-DEE (27%), ESES (7%), and Dravet syndrome (6%).

CONCLUSIONS

Many children with DEEs experience severe functional impairments, and few children have typical function. As precision therapies will emphasize nonseizures consequences of DEEs, understanding the nature of abilities and impairments will be critical to selecting appropriate outcome measures in therapeutic trials.

Fenfluramine for Treatment-Resistant Seizures in Patients With Dravet Syndrome Receiving Stiripentol-Inclusive Regimens: A Randomized Clinical Trial

Importance

Fenfluramine treatment may reduce monthly convulsive seizure frequency in patients with Dravet syndrome who have poor seizure control with their current stiripentol-containing antiepileptic drug regimens.

Objective

To determine whether fenfluramine reduced monthly convulsive seizure frequency relative to placebo in patients with Dravet syndrome who were taking stiripentol-inclusive regimens.

Design, Setting, and Participants

This double-blind, placebo-controlled, parallel-group randomized clinical trial was conducted in multiple centers. Eligible patients were children aged 2 to 18 years with a confirmed clinical diagnosis of Dravet syndrome who were receiving stable, stiripentol-inclusive antiepileptic drug regimens.

Interventions

Patients with 6 or more convulsive seizures during the 6-week baseline period were randomly assigned to receive fenfluramine, 0.4 mg/kg/d (maximum, 17 mg/d), or a placebo. After titration (3 weeks), patients' assigned dosages were maintained for 12 additional weeks. Caregivers recorded seizures via a daily electronic diary.

Main Outcomes and Measures

The primary efficacy end point was the change in mean monthly convulsive seizure frequency between fenfluramine and placebo during the combined titration and maintenance periods relative to baseline.

Results

A total of 115 eligible patients were identified; of these, 87 patients (mean [SD], age 9.1 [4.8] years; 50 male patients [57%]; mean baseline frequency of seizures, approximately 25 convulsive seizures per month) were enrolled and randomized to fenfluramine, 0.4 mg/kg/d (n = 43) or placebo (n = 44). Patients treated with fenfluramine achieved a 54.0% (95% CI, 35.6%-67.2%; P < .001) greater reduction in mean monthly convulsive seizure frequency than those receiving the placebo. With fenfluramine, 54% of patients demonstrated a clinically meaningful (≥50%) reduction in monthly convulsive seizure frequency vs 5% with placebo (P < .001). The median (range) longest seizure-free interval was 22 (3.0-105.0) days with fenfluramine and 13 (1.0-40.0) days with placebo (P = .004). The most common adverse events were decreased appetite (19 patients taking fenfluramine [44%] vs 5 taking placebo [11%]), fatigue (11 [26%] vs 2 [5%]), diarrhea (10 [23%] vs 3 [7%]), and pyrexia (11 [26%] vs 4 [9%]). Cardiac monitoring demonstrated no clinical or echocardiographic evidence of valvular heart disease or pulmonary arterial hypertension.

Conclusions and Relevance

Fenfluramine demonstrated significant improvements in monthly convulsive seizure frequency in patients with Dravet syndrome whose conditions were insufficiently controlled with stiripentol-inclusive antiepileptic drug regimens. Fenfluramine was generally well tolerated. Fenfluramine may represent a new treatment option for Dravet syndrome.

Trial Registration

ClinicalTrials.gov identifier: NCT02926898.

Incidence of Hypertension Among Children Treated With Adrenocorticotropic Hormone (ACTH) or Prednisolone for Infantile Spasms

Children with infantile spasms are often treated with hormonal therapies including adrenocorticotropic hormone (ACTH) and prednisolone. These have numerous systemic side effects including hypertension and, rarely, fatal cardiomyopathy; however, the incidence of these side effects has not been well described. This study aims to quantify the incidence and short-term sequelae of hypertension in this population. A retrospective chart review was performed at a single institution. Children 2 months to 2 years old with newly diagnosed infantile spasms treated from 2013 to 2017 were included. Variables collected included age, sex, etiology and treatment of infantile spasms, documented or missed diagnosis of hypertension, treatment of hypertension, echocardiogram results, referrals for hypertension, and persistence of hypertension 2 to 4 months after treatment. Analyses included descriptive statistics with percentiles, means, and medians. Differences between groups were assessed using Fisher exact tests. Hypertension occurred in 34/77 children (44%) during treatment with ACTH and 4/11 children (36%) during treatment with prednisolone. No child developed hypertension during treatment with nonhormonal therapies. The incidence of hypertension between ACTH and prednisolone groups was not significantly different (P = .75). The incidence of hypertension was significantly higher in the ACTH and prednisolone groups compared to the nonhormonal group (P < .001 for each). Sixteen children received echocardiograms, with no cases of cardiomyopathy. Two children had persistent hypertension at 2 months after discontinuation of hormonal therapy. Hypertension is a very common side effect of hormonal therapy for infantile spasms; however, few developed long-term hypertension and none developed cardiomyopathy. Further study is needed to determine the role of antihypertensive treatment for hormone-related hypertension.

Fenfluramine hydrochloride for the treatment of seizures in Dravet syndrome: a randomised, double-blind, placebo-controlled trial

BACKGROUND

Dravet syndrome is a rare, treatment-resistant developmental epileptic encephalopathy characterised by multiple types of frequent, disabling seizures. Fenfluramine has been reported to have antiseizure activity in observational studies of photosensitive epilepsy and Dravet syndrome. The aim of the present study was to assess the efficacy and safety of fenfluramine in patients with Dravet syndrome.

METHODS

In this randomised, double-blind, placebo-controlled clinical trial, we enrolled children and young adults with Dravet syndrome. After a 6-week observation period to establish baseline monthly convulsive seizure frequency (MCSF; convulsive seizures were defined as hemiclonic, tonic, clonic, tonic-atonic, generalised tonic-clonic, and focal with clearly observable motor signs), patients were randomly assigned through an interactive web response system in a 1:1:1 ratio to placebo, fenfluramine 0·2 mg/kg per day, or fenfluramine 0·7 mg/kg per day, added to existing antiepileptic agents for 14 weeks. The primary outcome was the change in mean monthly frequency of convulsive seizures during the treatment period compared with baseline in the 0·7 mg/kg per day group versus placebo; 0·2 mg/kg per day versus placebo was assessed as a key secondary outcome. Analysis was by modified intention to treat. Safety analyses included all participants who received at least one dose of study medication. This trial is registered with ClinicalTrials.gov with two identical protocols NCT02682927 and NCT02826863.

FINDINGS

Between Jan 15, 2016, and Aug 14, 2017, we assessed 173 patients, of whom 119 patients (mean age 9·0 years, 64 [54%] male) were randomly assigned to receive either fenfluramine 0·2 mg/kg per day (39), fenfluramine 0·7 mg/kg per day (40) or placebo (40). During treatment, the median reduction in seizure frequency was 74·9% in the fenfluramine 0·7 mg/kg group (from median 20·7 seizures per 28 days to 4·7 seizures per 28 days), 42·3% in the fenfluramine 0·2 mg/kg group (from median 17·5 seizures per 28 days to 12·6 per 28 days), and 19·2% in the placebo group (from median 27·3 per 28 days to 22·0 per 28 days). The study met its primary efficacy endpoint, with fenfluramine 0·7 mg/kg per day showing a 62·3% greater reduction in mean MCSF compared with placebo (95% CI 47·7-72·8, p<0·0001); fenfluramine 0·2 mg/kg per day showed a 32·4% reduction in mean MCSF compared with placebo (95% CI 6·2-52·3, p=0·0209). The most common adverse events (occurring in at least 10% of patients and more frequently in the fenfluramine groups) were decreased appetite, diarrhoea, fatigue, lethargy, somnolence, and decreased weight. Echocardiographic examinations revealed valve function within the normal physiological range in all patients during the trial and no signs of pulmonary arterial hypertension.

INTERPRETATION

In Dravet syndrome, fenfluramine provided significantly greater reduction in convulsive seizure frequency compared with placebo and was generally well tolerated, with no observed valvular heart disease or pulmonary arterial hypertension. Fenfluramine could be an important new treatment option for patients with Dravet syndrome.

FUNDING

Zogenix.

Infantile Spasms in Children With Down Syndrome: Identification and Treatment Response

Objectives. To evaluate infantile spasms in children with Down syndrome including assessment of efficacy of treatments, presence of treatment lag, and to identify risk factors that may predict the occurrence of infantile spasms in this population. Methods. Medical charts, electroencephalograms, and brain magnetic resonance images were evaluated in 37 children treated for infantile spasms at a single institution from 2005 to 2015. Results. Mean age at diagnosis was 9.16 months, with an average 1.38-month lag from spasms onset to start of medication. Prevalence of heart defects and pulmonary hypertension were significantly higher in those with infantile spams compared with those without. Eighty-one percent receiving adrenocorticotropic hormone as initial treatment experienced remission within 2 weeks, 94.1% had remission at 3 months compared with 18.8% at 2 weeks and 35.3% at 3 months for other first-line treatments. Type of treatment was the only predictor of good outcome. Conclusions. Results stress the importance of early recognition and adrenocorticotropic hormone treatment for this seizure disorder in children with Down syndrome.

Growth and endocrine function in children with Dravet syndrome

PURPOSE

Dravet syndrome is an intractable childhood epilepsy syndrome most often associated with an SCN1A mutation. In our clinical practice, several patients with Dravet syndrome were noted to have short stature and endocrine dysfunction. This has not been reported in the literature. Our study aim was to describe growth measurements and endocrine abnormalities in children with Dravet syndrome.

METHOD

A retrospective chart review was performed at a single institution. Eligibility criteria included clinical and genetic (SCN1A) diagnosis of Dravet syndrome. Records were reviewed for height and weight measurements and serologic evidence of endocrine abnormality, as well as patient demographics, anti-seizure medication, and family history. Age and gender specific trend of height and weight measurements, using z-scores, were compared to CDC growth curves (Centers for Disease Control and Prevention [1]).

RESULTS

Sixty-eight children were identified, 46% male, age 1-21 years, taking an average of 2.9 anti-seizure medications per patient. Mean growth parameter measurements were significant for decrease in height z-score of 0.10 (p=<0.001) and decrease in weight z-score of 0.09 (p=<0.01) for every year increase in age, such that with increasing age the cohort moved farther away from the mean. The average group height and weight z-score, at age 8, was -0.45 and -0.09, respectively. After adjusting for age, neither gender, family history, or anti-seizure medication was associated with height or weight z-score. Serologic endocrine results were available for 26 children (38%). This identified low insulin-like growth factor 1 (IGF-1) in 7/15 and low testosterone in 2/10. Two children received growth hormone supplementation. TSH testing was abnormal <10% of the time.

CONCLUSIONS

Comorbidities in children with Dravet syndrome may involve more systems than previously reported. We report a cohort of children with Dravet syndrome with reduced height and weight growth trend, as well as a subset with endocrine dysfunction evidenced by low IGF-1 and testosterone levels. Additional prospective research is needed to further define the significance of this relationship.

Infantile Spasms and Injuries of Prematurity: Short-Term Treatment-Based Response and Long-Term Outcomes

The association of infantile spasms and periventricular leukomalacia and/or intraventricular hemorrhage is well documented. Data regarding early treatment-based and long-term outcomes are limited. A retrospective chart review identified children with infantile spasms born prematurely (<37 weeks) with diagnoses of periventricular leukomalacia and/or intraventricular hemorrhage. Thirteen children were included. Median gestational age was 30 weeks and age of onset of infantile spasms was 8 months. Nine children had intraventricular hemorrhage, 10 had periventricular leukomalacia, and 6 children had both. Twelve of 13 children had resolution of spasms. In responders, the successful medication was adrenocorticotropic hormone (ACTH) in 7, topiramate in 3, and vigabatrin in 2. Follow-up after a median of 7.1 years found that all patients had developmental delay but only 1 had refractory epilepsy. Standard therapies (ACTH and vigabatrin) appeared to be more effective than other treatments. Developmental delay is common in children with periventricular leukomalacia / intraventricular hemorrhage and infantile spasms, but refractory epilepsy might be less frequent.

Clemizole and modulators of serotonin signalling suppress seizures in Dravet syndrome

Dravet syndrome is a catastrophic childhood epilepsy with early-onset seizures, delayed language and motor development, sleep disturbances, anxiety-like behaviour, severe cognitive deficit and an increased risk of fatality. It is primarily caused by de novo mutations of the SCN1A gene encoding a neuronal voltage-activated sodium channel. Zebrafish with a mutation in the SCN1A homologue recapitulate spontaneous seizure activity and mimic the convulsive behavioural movements observed in Dravet syndrome. Here, we show that phenotypic screening of drug libraries in zebrafish scn1 mutants rapidly and successfully identifies new therapeutics. We demonstrate that clemizole binds to serotonin receptors and its antiepileptic activity can be mimicked by drugs acting on serotonin signalling pathways e.g. trazodone and lorcaserin. Coincident with these zebrafish findings, we treated five medically intractable Dravet syndrome patients with a clinically-approved serotonin receptor agonist (lorcaserin, Belviq®) and observed some promising results in terms of reductions in seizure frequency and/or severity. Our findings demonstrate a rapid path from preclinical discovery in zebrafish, through target identification, to potential clinical treatments for Dravet syndrome.

Surgery for infants with catastrophic epilepsy: an analysis of complications and efficacy

PURPOSE

Infants with epilepsy often have a catastrophic course. There is a reluctance to operate in the very young, due to the perception of an unacceptable risk of morbidity with early operations. The purpose of this investigation was to better characterize the efficacy and safety of epilepsy surgery in infants.

METHODS

Epilepsy operations performed on children under 1 year old, between 2002 and 2013, were reviewed for demographic information, epilepsy characteristics, surgical approach, outcomes, and surgical complications.

RESULTS

Twenty-five patients, ages 11 days to 11.5 months (mean 4.7) at operation, were identified. All had daily seizures. Twenty-two (88%) had an abnormal magnetic resonance imaging (MRI). Sixteen (64%) patients underwent hemispherotomy at initial operation. Seven (28%) infants had grid placement followed by focal resection. Focal cortical dysplasia was the most common pathology (40%) followed by hemimegalencephaly (32%). Complications occurred in 36% of patients. These included hydrocephalus in five patients (20%). Two patients had significant intra-operative complications which required unplanned staging of their operations. Both recovered without permanent injury. Mean follow-up was 62.4 months. Twenty patients (80%) are seizure-free, and 10 (40%) are off anticonvulsant medication. Two patients are Engel class 2, and the remaining three patients were Engel class 4, one of whom died with status epilepticus from the contralateral hemisphere.

CONCLUSION

Infants with localization-related catastrophic epilepsy can have excellent outcomes from early epilepsy surgery. Complications are common in this patient group and proper diagnosis can be challenging. Young age should not exclude infants with catastrophic epilepsy from consideration for early surgical intervention.

Continuous infusion pentobarbital for refractory status epilepticus in children

The purpose of this retrospective medical chart review was to describe dosing regimens and outcomes in children who received continuous pentobarbital therapy for refractory status epilepticus. Thirty patients (age = 6.5 ± 5.1 years; 67% male) received a mean loading dose of 5.4 ± 2.8 mg/kg with an initial infusion of 1.1 ± 0.4 mg/kg/h. Maximum infusion dose was 4.8 ± 2 mg/kg/h. Thirty-three percent of patients achieved sustained burst suppression without relapse; 66.7% experienced relapse, but 60% of those (n = 12) eventually reachieved burst suppression. Children achieving burst suppression within 24 hours of pentobarbital initiation and those older than age 5 years were 1.5 times more likely to have a positive outcome. None of these variables, however, achieved significance (Fisher exact test). Ninety-three percent of patients required inotropes; 66% acquired an infection; 10% had metabolic acidosis; and 10% experienced pancreatitis. Poor outcomes (death, encephalopathy) were observed in 33% of patients.

Pediatric epilepsy: Five new things

Epilepsy in children can be very different from epilepsy in adults, both in seizure type and epilepsy syndrome. The goal in treating children is seizure freedom, no treatment side effects, and function that is no different from the general population. In a significant percentage of patients, this goal remains unachievable, but many aspects of epilepsy are becoming clearer. This review will highlight 5 areas where progress is being made to achieve these goals in pediatric epilepsy. Specific research animal models are being developed to reflect the unique features of different pediatric epilepsies. As genetic syndromes are better identified, for some patients this has led to improved treatment. New advances in drug therapy have led to 3 new medications approved for children. More effective drug choices can now be recommended due to comparative drug trials and better overall care of children can be provided due to awareness of the comorbidities of epilepsy.

The effects of dopaminergic/serotonergic reuptake inhibition on maternal behavior, maternal aggression, and oxytocin in the rat

Studies using dopaminergic and serotonergic agonists or antagonists implicate involvement of these systems in various aspects of early maternal behavior and postpartum aggression towards an intruder in rats, both of which are associated with the presence of oxytocin in specific brain regions. It is unclear however, if or how long-term uptake inhibition of either neurotransmitter system alone or in combination, affects oxytocin system dynamics or maternal behavior/aggression. Pregnant women frequently take drugs (antidepressants, cocaine) that induce long-term reuptake inhibition of dopamine and/or serotonin, thus it is important to understand these effects on behavior and biochemistry. Rat dams were treated throughout gestation with amfonelic acid, fluoxetine, or a combination of both, to investigate effects of reuptake inhibition of dopamine and serotonin systems respectively, on maternal behavior, aggression and oxytocin. The more appetitive aspects of maternal behavior (nesting, licking, touching) and activity were increased by the low dose of amfonelic acid, high dose of fluoxetine, or the high dose combination more than other treatments. Aggression was decreased by amfonelic acid and somewhat increased by fluoxetine. Dopamine uptake inhibition appears to have a strong effect on hippocampal oxytocin levels, while receptor dynamics may be more strongly affected by serotonin uptake inhibition.