Adaptive functioning and neurodevelopment in patients with Dravet syndrome: 12-month interim analysis of the BUTTERFLY observational study.

OBJECTIVE: The BUTTERFLY observational study aims to elucidate the natural trajectory of Dravet syndrome (DS) and associated comorbidities in order to establish a baseline for clinical therapies. We present the 12-month interim analysis of the study. MATERIALS AND METHODS: Patients with a genetically confirmed diagnosis of DS were enrolled in the study. Adaptive functioning and neurodevelopmental status were measured using the Vineland Adaptive Behavior Scale, Third Edition (Vineland-III), Bayley Scales of Infant Development, Third Edition (BSID-III), and Wechsler Preschool and Primary Scale of Intelligence, Fourth Edition (WPPSI-IV). Executive function, ambulatory function and locomotor activities, and overall clinical status were measured using the Behavior Rating Inventory of Executive Function - Preschool Version (BRIEF-P) scale, Gillette Functional Assessment Questionnaire (Gillette FAQ), and Clinician or Caregiver Global Impression of Change scales (CGI-C or CaGI-C) respectively. RESULTS: Overall, 36 patients were enrolled across three age groups, with 35 patients completing at least part or all of one post-baseline visit through Month 12. Significant improvements in receptive communication, as assessed by Vineland-III and BSID-III raw scores, and in verbal comprehension subtests, as assessed by WPPSI-IV raw scores, were observed in BUTTERFLY patients for the all-patient group. Many patients performed on the impaired end of the BRIEF-P Global Executive Composite scale at baseline suggesting difficulties in executive function, and no significant change was observed in BRIEF-P scores for the all-patient group. Most patients performed in the dynamic range of the Gillette FAQ at baseline, and no significant change was observed in Gillette FAQ scores for the all-patient group. Lastly, there was significant improvement observed in the CaGI-C scores for the all-patient group. SIGNIFICANCE: This BUTTERFLY interim analysis shows small improvements in communication skills along with stability in other developmental abilities across patients with DS enrolled in the study from baseline to Month 12.

Enabling endpoint development for interventional clinical trials in individuals with Angelman syndrome: a prospective, longitudinal, observational clinical study (FREESIAS).

BACKGROUND: Angelman syndrome (AS) is a rare neurodevelopmental disorder characterized by the absence of a functional UBE3A gene, which causes developmental, behavioral, and medical challenges. While currently untreatable, comprehensive data could help identify appropriate endpoints assessing meaningful improvements in clinical trials. Herein are reported the results from the FREESIAS study assessing the feasibility and utility of in-clinic and at-home measures of key AS symptoms. METHODS: Fifty-five individuals with AS (aged < 5 years: n = 16, 5-12 years: n = 27, ≥ 18 years: n = 12; deletion genotype: n = 40, nondeletion genotype: n = 15) and 20 typically developing children (aged 1-12 years) were enrolled across six USA sites. Several clinical outcome assessments and digital health technologies were tested, together with overnight 19-lead electroencephalography (EEG) and additional polysomnography (PSG) sensors. Participants were assessed at baseline (Clinic Visit 1), 12 months later (Clinic Visit 2), and during intermittent home visits. RESULTS: The participants achieved high completion rates for the clinical outcome assessments (adherence: 89-100% [Clinic Visit 1]; 76-91% [Clinic Visit 2]) and varied feasibility of and adherence to digital health technologies. The coronavirus disease 2019 (COVID-19) pandemic impacted participants' uptake of and/or adherence to some measures. It also potentially impacted the at-home PSG/EEG recordings, which were otherwise feasible. Participants achieved Bayley-III results comparable to the available natural history data, showing similar scores between individuals aged ≥ 18 and 5-12 years. Also, participants without a deletion generally scored higher on most clinical outcome assessments than participants with a deletion. Furthermore, the observed AS EEG phenotype of excess delta-band power was consistent with prior reports. CONCLUSIONS: Although feasible clinical outcome assessments and digital health technologies are reported herein, further improved assessments of meaningful AS change are needed. Despite the COVID-19 pandemic, remote assessments facilitated high adherence levels and the results suggested that at-home PSG/EEG might be a feasible alternative to the in-clinic EEG assessments. Taken altogether, the combination of in-clinic/at-home clinical outcome assessments, digital health technologies, and PSG/EEG may improve protocol adherence, reduce patient burden, and optimize study outcomes in AS and other rare disease populations.

Interim results of adaptive functioning and neurodevelopment in BUTTERFLY - An observational study of children and adolescents with Dravet syndrome.

PURPOSE: The purpose of this study is to evaluate adaptive functioning and neurodevelopment study assessments in a prospective study of patients with Dravet syndrome (DS). We present 3-month interim adaptive functioning and neurodevelopment data from the prospective, observational BUTTERFLY study in patients with DS aged 2-18 years. RESULTS: BUTTERFLY enrolled thirty-six patients divided 1:1:1 across three age groups (2-7: 8-12: and 13-18 years). Most enrolled patients were female (61.1%), white (94.4%), and non-Latino (83.3%) with a mean (standard deviation; SD) age of 10.8 (5.2) years and a mean (range) age of seizure onset of 0.4 (0.2-1.0) years. Patients used a mean (SD) of 3.5 (1.63) anti-seizure therapies at baseline. Regression analysis of the baseline Vineland Adaptive Behavior Scale - third edition (VABS-III) composite score indicated that the gap in adaptive function between patients with DS (n = 33) and neurotypical children widens with age. Similarly, developmental quotients calculated for patients who completed all Bayley Scales of Infant Development - third edition (BSID-III) subtests at baseline (n = 15) highlighted a gap in intellectual functioning between patients with DS and neurotypical children that widens with age. More patients in the two older age groups were able to validly complete the Wechsler Preschool and Primary Scale of Intelligence - fourth edition (WPPSI-IV) at baseline compared with the youngest age group. There were trends towards higher raw scores, albeit of low magnitude, in the oldest age group compared with the younger age two groups across multiple VABS-III domains and WPPSI-IV subtests. All three measures showed no significant change in the all-patients analyses and demonstrated relatively low intra-patient variability from baseline to Month 3. CONCLUSIONS: Three-month interim data from BUTTERFLY demonstrated the feasibility of utilizing the VABS-III, BSID-III, and WPPSI-IV for the assessment of adaptive function and neurodevelopment in future clinical studies of DS. Moreover, many patients with DS appear to gain neurodevelopmental and adaptive function skills over time, although at a slower rate and lower magnitude than that seen in the neurotypical population.

Safety and Efficacy of Natalizumab as Adjunctive Therapy for People With Drug-Resistant Epilepsy: A Phase 2 Study.

BACKGROUND AND OBJECTIVES: To explore efficacy/safety of natalizumab, a humanized monoclonal anti-α4-integrin antibody, as adjunctive therapy in adults with drug-resistant focal epilepsy. METHODS: Participants with ≥6 seizures during the 6-week baseline period were randomized 1:1 to receive natalizumab 300 mg IV or placebo every 4 weeks for 24 weeks. Primary efficacy outcome was change from baseline in log-transformed seizure frequency, with a predefined threshold for therapeutic success of 31% relative reduction in seizure frequency over the placebo group. Countable seizure types were focal aware with motor signs, focal impaired awareness, and focal to bilateral tonic-clonic. Secondary efficacy endpoints/safety were also assessed. RESULTS: Of 32 and 34 participants dosed in the natalizumab 300 mg and placebo groups, 30 (94%) and 31 (91%) completed the placebo-controlled treatment period, respectively (one participant was randomized to receive natalizumab but not dosed due to IV complications). Estimated relative change in seizure frequency of natalizumab over placebo was -14.4% (95% confidence interval [CI] -46.1%-36.1%; p = 0.51). The proportion of participants with ≥50% reduction from baseline in seizure frequency was 31.3% for natalizumab and 17.6% for placebo (odds ratio 2.09, 95% CI 0.64-6.85; p = 0.22). Adverse events were reported in 24 (75%) and 22 (65%) participants receiving natalizumab vs placebo. DISCUSSION: Although the threshold to demonstrate efficacy was not met, there were no unexpected safety findings and further exploration of possible anti-inflammatory therapies for drug-resistant epilepsy is warranted. TRIAL REGISTRATION INFORMATION: The ClinicalTrials.gov registration number is NCT03283371. CLASSIFICATION OF EVIDENCE: This study provides Class I evidence that IV natalizumab every 4 weeks, compared to placebo, did not significantly change seizure frequency in adults with drug-resistant epilepsy. The study lacked the precision to exclude an important effect of natalizumab.

Use of an electronic seizure diary in a randomized, controlled trial of natalizumab in adult participants with drug-resistant focal epilepsy.

OBJECTIVE: To analyze electronic diary (e-diary) use in a phase 2, randomized, controlled clinical trial (OPUS; NCT03283371) of natalizumab in adult participants with drug-resistant focal epilepsy. METHODS: We developed an e-diary, which incorporated an episodic seizure diary and a daily diary reminder, for use as the primary source to record participants' daily seizure activity in the OPUS phase 2 clinical trial. Participants and/or their designated caregivers made e-diary entries by selecting seizure descriptions generated in the participants' and/or caregivers' own words at the time of screening. Seizures and seizure-free days were reported for the current day and for up to 5 and 4 retrospective days, respectively. A record of seizure symptoms entered within the prior 5-day period was displayed on accessing the diary. Changes were not permitted in the e-diary once a seizure record was saved unless a data change request was made. A paper backup diary was available. RESULTS: E-diary entries (N = 15,176) from the 6-week baseline period and subsequent 24-week placebo-controlled period were analyzed for 66 adults who were randomized and dosed in the OPUS trial. The overall e-diary compliance, defined as the total number of days with any entry out of the total number of days in the baseline and placebo-controlled periods for all participants combined, was 83.6%. Caregivers made 190 (1.3%) e-diary entries. Day-of-event e-diary entries totaled 11,248 (74.1%). At least one paper backup diary was used by 36 (54.5%) participants. SIGNIFICANCE: Our data highlight that good e-diary compliance can be achieved across participants in randomized clinical trials in adult focal epilepsy. In addition to identifying and addressing any barriers that may prevent a minority of participants from achieving good e-diary compliance, consideration of e-diary elements, such as recall period and reporting of seizure-free days, will facilitate the most accurate data capture in epilepsy clinical trials.

Lacosamide in the treatment of acute recurrent seizures and periodic epileptiform patterns in critically ill patients.

We investigated the safety, tolerability, and effectiveness of lacosamide (LCM) in patients with acute recurrent seizures or with periodic epileptiform activity captured during continuous EEG monitoring. A total of 17 patients received LCM; 12 patients received LCM as a second or third antiepileptic drug (AED), one patient as a fourth AED, and one patient as a fifth AED. No additional AEDs were introduced after LCM in 15 patients. Twelve patients responded to LCM with improvement in the seizures or periodic epileptiform activity. Two patients required further AED management or burst suppression. No adverse effects, including symptomatic bradycardia and allergic reactions, were seen for intravenous infusion dosages up to 300 mg. Eleven patients were eventually discharged on LCM. LCM is an important new AED in the add-on treatment of acute recurrent seizures and periodic epileptiform activity in critically ill patients.

Biophysical and pharmacological characterization of hypotonically activated chloride currents in cortical astrocytes.

Rat cortical astrocytes regulate their cell volume in response to hypotonic challenge. This regulation is believed to depend largely on the release of chloride or organic osmolytes through anion channels. Using whole-cell recordings, we identified weakly outwardly rectifying chloride currents that could be activated in response to hypotonic challenge. These currents exhibited the following permeability sequence upon replacement of chloride in the bathing solution with various anions: I- > NO3- > Cl- > Gluc- > or = MeS- > Ise-. Interestingly, extracellular I-, albeit showing the greatest permeability, blocked the currents with an IC50 of approximately 50 mM. Currents were almost completely inhibited by 123 microM NPPB and partially inhibited by 200 microM niflumic acid or 200 microM DIDS. Additionally, the total number of Cl- ions effluxed through the hypotonically activated channels was markedly similar to the total solute efflux during volume regulation. We therefore propose the hypotonically activated chloride channel as a major contributor to volume regulation of astrocytes. To examine potential candidate chloride channel genes expressed by astrocytes, we employed RT-PCR to demonstrate the presence of transcripts for ClC-2, 3, 4, 5, and 7, as well as for VDAC and CFTR in cultured astrocytes. Moreover, we performed immunostaining with antibodies against each of these channels and showed the strongest expression of ClC-2 and ClC-3, strong expression of ClC-5 and VDAC, weak expression of ClC-7 and very weak expression of ClC-4 and CFTR. Intriguingly, although we found at least seven Cl- channel proteins from three different gene families in astrocytes, none appeared to be active in resting cells.

Contribution of chloride channels to volume regulation of cortical astrocytes.

The objective of this study was to determine the relative contribution of Cl(-) channels to volume regulation of cultured rat cortical astrocytes after hypotonic cell swelling. Using a Coulter counter, we showed that cortical astrocytes regulate their cell volume by approximately 60% within 45 min after hypotonic challenge. This volume regulation was supported when Cl(-) was replaced with Br(-), NO(3)(-), methanesulfonate(-), or acetate(-) but was inhibited when Cl(-) was replaced with isethionate(-) or gluconate(-). Additionally, substitution of Cl(-) with I(-) completely blocked volume regulation. Volume regulation was unaffected by furosemide or bumetanide, blockers of KCl transport, but was inhibited by Cl(-) channel blockers, including 5-nitro-2-(3-phenylpropylamino)benzoic acid (NPPB), 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS), and niflumic acid. Surprisingly, the combination of Cd(2+) with NPPB, DIDS, or niflumic acid inhibited regulation to a greater extent than any of these drugs alone. Volume regulation did not differ among astrocytes cultured from different brain regions, as cerebellar and hippocampal astrocytes exhibited behavior identical to that of cortical astrocytes. These data suggest that Cl(-) flux through ion channels rather than transporters is essential for volume regulation of cultured astrocytes in response to hypotonic challenge.