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Whyte-Fagundes PA, Vance A, Carroll A, Figueroa F, Manukyan C, Baraban SC. Testing of putative antiseizure medications in a preclinical Dravet syndrome zebrafish model. Brain Commun 2024; 6:fcae135. [PMID: 38707709 PMCID: PMC11069116 DOI: 10.1093/braincomms/fcae135] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 03/27/2024] [Accepted: 04/12/2024] [Indexed: 05/07/2024] Open
Abstract
Dravet syndrome is a severe genetic epilepsy primarily caused by de novo mutations in a voltage-activated sodium channel gene (SCN1A). Patients face life-threatening seizures that are largely resistant to available anti-seizure medications. Preclinical Dravet syndrome animal models are a valuable tool to identify candidate anti-seizure medications for these patients. Among these, scn1lab mutant zebrafish, exhibiting spontaneous seizure-like activity, are particularly amenable to large-scale drug screening. Thus far, we have screened more than 3000 drug candidates in scn1lab zebrafish mutants, identifying valproate, stiripentol, and fenfluramine e.g. Food and Drug Administration-approved drugs, with clinical application in the Dravet syndrome population. Successful phenotypic screening in scn1lab mutant zebrafish is rigorous and consists of two stages: (i) a locomotion-based assay measuring high-velocity convulsive swim behaviour and (ii) an electrophysiology-based assay, using in vivo local field potential recordings, to quantify electrographic seizure-like events. Historically, nearly 90% of drug candidates fail during translation from preclinical models to the clinic. With such a high failure rate, it becomes necessary to address issues of replication and false positive identification. Leveraging our scn1lab zebrafish assays is one approach to address these problems. Here, we curated a list of nine anti-seizure drug candidates recently identified by other groups using preclinical Dravet syndrome models: 1-Ethyl-2-benzimidazolinone, AA43279, chlorzoxazone, donepezil, lisuride, mifepristone, pargyline, soticlestat and vorinostat. First-stage locomotion-based assays in scn1lab mutant zebrafish identified only 1-Ethyl-2-benzimidazolinone, chlorzoxazone and lisuride. However, second-stage local field potential recording assays did not show significant suppression of spontaneous electrographic seizure activity for any of the nine anti-seizure drug candidates. Surprisingly, soticlestat induced frank electrographic seizure-like discharges in wild-type control zebrafish. Taken together, our results failed to replicate clear anti-seizure efficacy for these drug candidates highlighting a necessity for strict scientific standards in preclinical identification of anti-seizure medications.
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Affiliation(s)
- Paige A Whyte-Fagundes
- Epilepsy Research Laboratory and Weill Institute for Neuroscience, Department of Neurological Surgery, University of California San Francisco, San Francisco, CA 94143, USA
| | - Anjelica Vance
- Epilepsy Research Laboratory and Weill Institute for Neuroscience, Department of Neurological Surgery, University of California San Francisco, San Francisco, CA 94143, USA
| | - Aloe Carroll
- Behavioral Neurosciences, Northeastern University, Boston, MA 02115, USA
| | - Francisco Figueroa
- Epilepsy Research Laboratory and Weill Institute for Neuroscience, Department of Neurological Surgery, University of California San Francisco, San Francisco, CA 94143, USA
| | - Catherine Manukyan
- Helen Wills Neuroscience Institute, University of California, Berkeley, CA 94720, USA
| | - Scott C Baraban
- Epilepsy Research Laboratory and Weill Institute for Neuroscience, Department of Neurological Surgery, University of California San Francisco, San Francisco, CA 94143, USA
- Helen Wills Neuroscience Institute, University of California, Berkeley, CA 94720, USA
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Xu Y, Chen D, Liu L. Optimal dose of fenfluramine in adjuvant treatment of drug-resistant epilepsy: evidence from randomized controlled trials. Front Neurol 2024; 15:1371704. [PMID: 38590719 PMCID: PMC10999678 DOI: 10.3389/fneur.2024.1371704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Accepted: 03/08/2024] [Indexed: 04/10/2024] Open
Abstract
Objective Several clinical trials have suggested that fenfluramine (FFA) is effective for the treatment of epilepsy in Dravet syndrome (DS) and Lennox-Gastaut syndrome (LGS). However, the exploration of its optimal target dose is ongoing. This study aimed to summarize the best evidence to inform this clinical issue. Materials and methods We searched PubMed, Embase (via Ovid), and Web of Science for relevant literature published before December 1st, 2023. Randomized, double-blind, placebo-controlled studies that evaluated the efficacy, safety, and tolerability of FFA in DS and LGS were identified and meta-analysis was performed according to doses. The study was registered with PROSPERO (CRD42023392454). Results Six hundred and twelve patients from four randomized controlled trials were enrolled. The results demonstrated that FFA at 0.2, 0.4, or 0.7 mg/kg/d showed significantly greater efficacy compared to placebo in terms of at least 50% reduction (p < 0.001, p < 0.001, p < 0.001) and at least 75% reduction (p < 0.001, p = 0.007, p < 0.001) in monthly seizure frequency from baseline. Moreover, significantly more patients receiving FFA than placebo were rated as much improved or very much improved in CGI-I by both caregivers/parents and investigators (p < 0.001). The most common treatment-emergent adverse events were decreased appetite, diarrhea, fatigue, and weight loss, with no valvular heart disease or pulmonary hypertension observed in any participant. For dose comparison, 0.7 mg/kg/d group presented higher efficacy on at least 75% reduction in seizure (p = 0.006) but not on at least 50% reduction. Weight loss (p = 0.002), decreased appetite (p = 0.04), and all-cause withdrawal (p = 0.036) were more common in 0.7 mg/kg/d group than 0.2 mg/kg/d. There was no statistical difference in other safety parameters between these two groups. Conclusion The higher range of the licensed dose achieves the optimal balance between efficacy, safety, and tolerability in patients with DS and LGS. Clinical trial registration https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42023392454.
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Affiliation(s)
| | | | - Ling Liu
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, Sichuan, China
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Mittur A, Madanick R, Langlois M, Boyd B. Effect of Hepatic Impairment on the Pharmacokinetics of Fenfluramine and Norfenfluramine. J Clin Pharmacol 2024. [PMID: 38523492 DOI: 10.1002/jcph.2431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Accepted: 02/23/2024] [Indexed: 03/26/2024]
Abstract
Fenfluramine (Fintepla®) is approved for the treatment of seizures associated with the rare epileptic encephalopathies Dravet syndrome and Lennox-Gastaut syndrome. Fenfluramine is extensively metabolized; thus, patients with hepatic impairment (HI) might experience changes in exposure to fenfluramine or its metabolites. In this phase 1 study, we investigated the pharmacokinetics (PK) and safety of a single oral dose of 0.35 mg/kg fenfluramine in subjects with mild (n = 8), moderate (n = 8), or severe (n = 7) HI (Child-Pugh A/B/C, respectively) and healthy control subjects (n = 22) matched for sex, age, and BMI. All subjects underwent serial sampling to determine total plasma concentrations of fenfluramine and its active metabolite, norfenfluramine. Hepatic impairment was associated with increases in fenfluramine exposures, mainly area-under-the-curve (AUC). Geometric least squares mean ratios (90% confidence intervals) for fenfluramine AUC0-∞ in mild, moderate, and severe HI versus healthy controls were 1.98 (1.36-2.90), 2.13 (1.43-3.17), and 2.77 (1.82-4.24), respectively. Changes in exposure to norfenfluramine in mild, moderate, and severe HI were minimal compared with normal hepatic function. Exposures to fenfluramine and norfenfluramine in all HI groups were within the ranges that have been characterized in the overall development program, including ranges examined in exposure-response relationships for efficacy and safety in patients, and determined to have an acceptable safety profile. Mild and moderate HI had a modest effect on fenfluramine exposure that was not clinically meaningful, whereas the higher fenfluramine exposure in severe HI may require dose reduction based on general caution in this population. The modest decrease in norfenfluramine exposure is not considered clinically relevant.
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Affiliation(s)
| | - Ryan Madanick
- PPD, Thermo Fisher Scientific, Morrisville, North Carolina, USA
| | | | - Brooks Boyd
- UCB Biosciences, Inc, Morrisville, North Carolina, USA
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Nieoczym D, Marszalek-Grabska M, Szalak R, Kundap U, Kaczor AA, Wrobel TM, Kosheva N, Komar M, Abram M, Esguerra CV, Samarut E, Pieróg M, Jakubiec M, Kaminski K, Kukula-Koch W, Gawel K. A comprehensive assessment of palmatine as anticonvulsant agent - In vivo and in silico studies. Biomed Pharmacother 2024; 172:116234. [PMID: 38325264 DOI: 10.1016/j.biopha.2024.116234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 01/22/2024] [Accepted: 01/29/2024] [Indexed: 02/09/2024] Open
Abstract
Previously, we demonstrated that palmatine (PALM) - an isoquinoline alkaloid from Berberis sibrica radix, exerted antiseizure activity in the pentylenetetrazole (PTZ)-induced seizure assay in larval zebrafish. The aim of the present study was to more precisely characterize PALM as a potential anticonvulsant drug candidate. A range of zebrafish and mouse seizure/epilepsy models were applied in the investigation. Immunostaining analysis was conducted to assess the changes in mouse brains, while in silico molecular modelling was performed to determine potential targets for PALM. Accordingly, PALM had anticonvulsant effect in ethyl 2-ketopent-4-enoate (EKP)-induced seizure assay in zebrafish larvae as well as in the 6 Hz-induced psychomotor seizure threshold and timed infusion PTZ tests in mice. The protective effect in the EKP-induced seizure assay was confirmed in the local field potential recordings. PALM did not affect seizures in the gabra1a knockout line of zebrafish larvae. In the scn1Lab-/- zebrafish line, pretreatment with PALM potentiated seizure-like behaviour of larvae. Repetitive treatment with PALM, however, did not reduce development of PTZ-induced seizure activity nor prevent the loss of parvalbumin-interneurons in the hippocampus of the PTZ kindled mice. In silico molecular modelling revealed that the noted anticonvulsant effect of PALM in EKP-induced seizure assay might result from its interactions with glutamic acid decarboxylase and/or via AMPA receptor non-competitive antagonism. Our study has demonstrated the anticonvulsant activity of PALM in some experimental models of seizures, including a model of pharmacoresistant seizures induced by EKP. These results indicate that PALM might be a suitable new drug candidate but the precise mechanism of its anticonvulsant activity has to be determined.
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Affiliation(s)
- Dorota Nieoczym
- Chair of Animal Physiology and Pharmacology, Institute of Biology and Biochemistry, Faculty of Biology and Biotechnology, Maria Curie-Skłodowska University, Akademicka Str. 19, 20-033 Lublin, Poland
| | - Marta Marszalek-Grabska
- Department of Experimental and Clinical Pharmacology, Medical University of Lublin, Jaczewskiego Str. 8b, 20-090 Lublin, Poland
| | - Radoslaw Szalak
- Department of Animal Anatomy and Histology, Faculty of Veterinary Medicine, University of Life Sciences, 12 Akademicka St., 20-950 Lublin, Poland
| | - Uday Kundap
- Research Center of the University of Montreal Hospital Center (CRCHUM), Department of Neurosciences, Université de Montréal, Montréal, QC H2X 0A9, Canada; Canada East Spine Centre, Saint John Regional Hospital, Department of Spine and Orthopaedics surgery, Horizon Health Network, Saint John, NB E2L 4L4, Canada
| | - Agnieszka A Kaczor
- Department of Synthesis and Chemical Technology of Pharmaceutical Substances with Computer Modeling Laboratory, Faculty of Pharmacy, Medical University of Lublin, 4A Chodżki St., PL-20093 Lublin, Poland; School of Pharmacy, University of Eastern Finland, Yliopistonranta 1, P.O. Box 1627, FI-70211 Kuopio, Finland
| | - Tomasz M Wrobel
- Department of Synthesis and Chemical Technology of Pharmaceutical Substances with Computer Modeling Laboratory, Faculty of Pharmacy, Medical University of Lublin, 4A Chodżki St., PL-20093 Lublin, Poland
| | - Nataliia Kosheva
- Department of Experimental and Clinical Pharmacology, Medical University of Lublin, Jaczewskiego Str. 8b, 20-090 Lublin, Poland
| | - Malgorzata Komar
- Department of Animal Anatomy and Histology, Faculty of Veterinary Medicine, University of Life Sciences, 12 Akademicka St., 20-950 Lublin, Poland
| | - Michal Abram
- Department of Medicinal Chemistry, Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9, 30-688 Cracow, Poland
| | - Camila V Esguerra
- Chemical Neuroscience Group, Centre for Molecular Medicine Norway, University of Oslo, Gaustadalleen 21, Forskningsparken, 0349 Oslo, Norway
| | - Eric Samarut
- Research Center of the University of Montreal Hospital Center (CRCHUM), Department of Neurosciences, Université de Montréal, Montréal, QC H2X 0A9, Canada; Neurosciences Department, University of Montreal, Montreal, QC, Canada
| | - Mateusz Pieróg
- Chair of Animal Physiology and Pharmacology, Institute of Biology and Biochemistry, Faculty of Biology and Biotechnology, Maria Curie-Skłodowska University, Akademicka Str. 19, 20-033 Lublin, Poland
| | - Marcin Jakubiec
- Department of Medicinal Chemistry, Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9, 30-688 Cracow, Poland
| | - Krzysztof Kaminski
- Department of Medicinal Chemistry, Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9, 30-688 Cracow, Poland
| | - Wirginia Kukula-Koch
- Department of Pharmacognosy with Medicinal Plants Garden, Medical University of Lublin, Chodzki Str. 1, 20-093 Lublin, Poland
| | - Kinga Gawel
- Department of Experimental and Clinical Pharmacology, Medical University of Lublin, Jaczewskiego Str. 8b, 20-090 Lublin, Poland.
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Tong J, Ji T, Liu T, Liu J, Chen Y, Li Z, Lu N, Li Q. Efficacy and safety of six new antiseizure medications for adjunctive treatment of focal epilepsy and epileptic syndrome: A systematic review and network meta-analysis. Epilepsy Behav 2024; 152:109653. [PMID: 38277848 DOI: 10.1016/j.yebeh.2024.109653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 01/08/2024] [Accepted: 01/15/2024] [Indexed: 01/28/2024]
Abstract
OBJECTIVE This study aimed to evaluate the efficacy and safety of six new antiseizure medications (ASMs) for adjunctive treatment in adult patients with focal epilepsy and adolescents with Dravet syndrome (DS), Lennox-Gastaut syndrome (LGS), or tuberous sclerosis complex (TSC). METHODS A comprehensive literature search was performed using PubMed, Medline, Embase, and Cochrane library databases from inception to October 13, 2023. We included published studies for a systematic review and a network meta-analysis (NMA). The efficacy and safety were reported in terms of a 50% response rate and dropout rate along with serious adverse events (SAEs). The outcomes were ranked with the surface under the cumulative ranking curve (SUCRA). RESULTS Twenty eligible trials with 5516 patients and 21 interventions, including placebo, contributed to the analysis. Included ASMs were brivaracetam (BRV), cenobamate (CBM), cannabidiol (CBD), fenfluramine (FFM), everolimus (ELM), and soticlestat (SLT). The six new ASMs were compared in four different epilepsy subtypes. In focal epilepsy treatment, BRV seemed to be safe [vs placebo, risk ratio (RR) = 0.69, 95 % confidence interval (CI): 0.25-1.91] and effective (vs placebo, RR = 2.18, 95 % CI: 1.25-3.81). In treating focal epilepsy, CBM 300 mg was more effective at a 50 % response rate (SUCRA 91.8 %) compared with BRV and CBD. However, with the increase in dosage, more SAEs (SUCRA 85.6 %) appeared compared with other ASMs. CBD had good efficacy on LGS (SUCRA 88.4) and DS (SUCRA 66.2), but the effect on adult focal epilepsy was not better than that of placebo [vs placebo, RR = 0.83 (0.36-1.93)]. The NMA indicated that the likelihood of the most appropriate intervention (SUCRA 91.2 %) with minimum side effects(SUCRA 12.5 %)for the DS was FFM. Compared with CBD, high exposure to ELM demonstrated a more effective treatment of TSC (SUCRA 89.7 %). More high-quality SLT studies are needed to further evaluate the efficacy and safety. The comparison-adjusted funnel plots of annualized relapse rate and side effects in the included studies revealed no significant funnel plot asymmetry. CONCLUSIONS This NMA indicated that the most effective treatment strategy for focal epilepsy, DS, Lennox-Gastaut syndrome, and TSC, respectively, included CBM 300 mg, FFM, CBD, and ELM. However, the aforementioned findings need further confirmation.
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Affiliation(s)
- Jingyi Tong
- Department of Neurology, The First Affiliated Hospital of Hainan Medical University, Haikou 570102, China; Key Laboratory of Brain Science Research and Transformation in Tropical Environment of Hainan Province, Hainan Medical University, Haikou 570102, China
| | - Tingting Ji
- Department of Neurology, The First Affiliated Hospital of Hainan Medical University, Haikou 570102, China; Key Laboratory of Brain Science Research and Transformation in Tropical Environment of Hainan Province, Hainan Medical University, Haikou 570102, China
| | - Ting Liu
- Department of Neurology, The First Affiliated Hospital of Hainan Medical University, Haikou 570102, China; Key Laboratory of Brain Science Research and Transformation in Tropical Environment of Hainan Province, Hainan Medical University, Haikou 570102, China
| | - Jiaqi Liu
- Department of Neurology, The First Affiliated Hospital of Hainan Medical University, Haikou 570102, China; Key Laboratory of Brain Science Research and Transformation in Tropical Environment of Hainan Province, Hainan Medical University, Haikou 570102, China
| | - Yibin Chen
- Department of Neurology, The First Affiliated Hospital of Hainan Medical University, Haikou 570102, China; Key Laboratory of Brain Science Research and Transformation in Tropical Environment of Hainan Province, Hainan Medical University, Haikou 570102, China
| | - Zongjun Li
- Department of Neurology, The First Affiliated Hospital of Hainan Medical University, Haikou 570102, China; Key Laboratory of Brain Science Research and Transformation in Tropical Environment of Hainan Province, Hainan Medical University, Haikou 570102, China
| | - Na Lu
- Hainan Medical University, Haikou 570102, China.
| | - Qifu Li
- Department of Neurology, The First Affiliated Hospital of Hainan Medical University, Haikou 570102, China; Key Laboratory of Brain Science Research and Transformation in Tropical Environment of Hainan Province, Hainan Medical University, Haikou 570102, China.
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Strzelczyk A, Becker H, Tako L, Hock S, Hattingen E, Rosenow F, Mann C. Fenfluramine for the treatment of status epilepticus: use in an adult with Lennox-Gastaut syndrome and literature review. Neurol Res Pract 2024; 6:10. [PMID: 38383582 PMCID: PMC10882814 DOI: 10.1186/s42466-023-00306-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 12/28/2023] [Indexed: 02/23/2024] Open
Abstract
BACKGROUND Novel treatments are needed to control refractory status epilepticus (SE). This study aimed to assess the potential effectiveness of fenfluramine (FFA) as an acute treatment option for SE. We present a summary of clinical cases where oral FFA was used in SE. METHODS A case of an adult patient with Lennox-Gastaut syndrome (LGS) who was treated with FFA due to refractory SE is presented in detail. To identify studies that evaluated the use of FFA in SE, we performed a systematic literature search. RESULTS Four case reports on the acute treatment with FFA of SE in children and adults with Dravet syndrome (DS) and LGS were available. We report in detail a 30-year-old woman with LGS of structural etiology, who presented with generalized tonic and dialeptic seizures manifesting at high frequencies without a return to clinical baseline constituting the diagnosis of SE. Treatment with anti-seizure medications up to lacosamide 600 mg/d, brivaracetam 300 mg/d, valproate 1,600 mg/d, and various benzodiazepines did not resolve the SE. Due to ongoing refractory SE and following an unremarkable echocardiography, treatment was initiated with FFA, with an initial dose of 10 mg/d (0.22 mg/kg body weight [bw]) and fast up-titration to 26 mg/d (0.58 mg/kg bw) within 10 days. Subsequently, the patient experienced a resolution of SE within 4 days, accompanied by a notable improvement in clinical presentation and regaining her mobility, walking with the assistance of physiotherapists. In the three cases reported in the literature, DS patients with SE were treated with FFA, and a cessation of SE was observed within a few days. No treatment-emergent adverse events were observed during FFA treatment in any of the four cases. CONCLUSIONS Based on the reported cases, FFA might be a promising option for the acute treatment of SE in patients with DS and LGS. Observational data show a decreased SE frequency while on FFA, suggesting a potentially preventive role of FFA in these populations. KEY POINTS We summarize four cases of refractory status epilepticus (SE) successfully treated with fenfluramine. Refractory SE resolved after 4-7 days on fenfluramine. Swift fenfluramine up-titration was well-tolerated during SE treatment. Treatment-emergent adverse events on fenfluramine were not observed. Fenfluramine might be a valuable acute treatment option for SE in Dravet and Lennox-Gastaut syndromes.
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Affiliation(s)
- Adam Strzelczyk
- Goethe-University Frankfurt, Epilepsy Center Frankfurt Rhine-Main, Department of Neurology, University Hospital Frankfurt, Schleusenweg 2-16 (Haus 95), 60528, Frankfurt am Main, Germany.
| | - Hendrik Becker
- Goethe-University Frankfurt, Epilepsy Center Frankfurt Rhine-Main, Department of Neurology, University Hospital Frankfurt, Schleusenweg 2-16 (Haus 95), 60528, Frankfurt am Main, Germany
| | - Lisa Tako
- Goethe-University Frankfurt, Epilepsy Center Frankfurt Rhine-Main, Department of Neurology, University Hospital Frankfurt, Schleusenweg 2-16 (Haus 95), 60528, Frankfurt am Main, Germany
| | - Susanna Hock
- Goethe-University Frankfurt, Epilepsy Center Frankfurt Rhine-Main, Department of Neurology, University Hospital Frankfurt, Schleusenweg 2-16 (Haus 95), 60528, Frankfurt am Main, Germany
| | - Elke Hattingen
- Goethe-University Frankfurt, Department of Neuroradiology, University Hospital Frankfurt, Frankfurt am Main, Germany
| | - Felix Rosenow
- Goethe-University Frankfurt, Epilepsy Center Frankfurt Rhine-Main, Department of Neurology, University Hospital Frankfurt, Schleusenweg 2-16 (Haus 95), 60528, Frankfurt am Main, Germany
| | - Catrin Mann
- Goethe-University Frankfurt, Epilepsy Center Frankfurt Rhine-Main, Department of Neurology, University Hospital Frankfurt, Schleusenweg 2-16 (Haus 95), 60528, Frankfurt am Main, Germany
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Erenburg N, Hamed R, Shaul C, Barasch D, Perucca E, Bialer M. Pharmacokinetics of d- and l-norfenfluramine following their administration as individual enantiomers in rats. Epilepsia 2024; 65:e14-e19. [PMID: 38041575 DOI: 10.1111/epi.17846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 11/20/2023] [Accepted: 11/30/2023] [Indexed: 12/03/2023]
Abstract
The effect of fenfluramine and norfenfluramine enantiomers in rodent seizure models and their correlation with the pharmacokinetics of d- and l-fenfluramine in rats have been reported recently. To complement these findings, we investigated the pharmacokinetics of d- and l- norfenfluramine in rat plasma and brain. Sprague-Dawley rats were injected intraperitoneally with 20 mg/kg and 1 mg/kg l- norfenfluramine. A 1 mg/kg dose of d-norfenfluramine was used because higher doses caused severe toxicity. The concentration of each enantiomer in plasma and brain was determined at different time points by liquid chromatography/mass spectrometry. Pharmacokinetic parameters were compared between norfenfluramine enantiomers, and with those reported previously for fenfluramine enantiomers after a 20 mg/kg, i.p., dose. All enantiomers were absorbed rapidly and eliminated, with half-lives ranging from 0.9 h (l-fenfluramine) to 6.1 h (l- norfenfluramine, 20 mg/kg) in plasma, and from 3.6 h (d-fenfluramine) to 8.0 h (l-fenfluramine) in brain. Brain-to-plasma concentration ratios ranged from 15.4 (d-fenfluramine) to 27.6 (d-norfenfluramine), indicating extensive brain penetration. The fraction of d- and l-fenfluramine metabolized to norfenfluramine was estimated to be close to unity. This work is part of ongoing investigations to determine the potential value of developing enantiomerically pure l-fenfluramine or l-norfenfluramine as follow-up compounds to the marketed racemic fenfluramine.
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Affiliation(s)
- Natalia Erenburg
- Institute of Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Roa'a Hamed
- Institute of Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Chanan Shaul
- Institute of Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Dinorah Barasch
- Institute of Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Emilio Perucca
- Department of Medicine (Austin Health), University of Melbourne, Melbourne, Victoria, Australia
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, Australia
| | - Meir Bialer
- Institute of Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
- David R. Bloom Center for Pharmacy, The Hebrew University of Jerusalem, Jerusalem, Israel
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Valls Carbó A, Beltrán Á, Sánchez-Miranda Román I, Cabal B, Gómez-Porro P, Aledo-Serrano Á, López Sobrino G, Ayuga F, Gómez Eguilaz M, Gil-Nagel A. What have we learned from the real-world efficacy of FFA in DS and LGS? A post-marketing study in clinical practice. Epilepsy Behav 2024; 151:109620. [PMID: 38194770 DOI: 10.1016/j.yebeh.2024.109620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 12/29/2023] [Accepted: 01/02/2024] [Indexed: 01/11/2024]
Abstract
OBJECTIVE To evaluate the effectiveness and tolerability of fenfluramine (FFA) in routine clinical practice treating real-world populations with Dravet syndrome (DS) and Lennox-Gastaut syndrome (LGS). METHODS This was a retrospective analysis of patients with DS or LGS who initiated FFA treatment from 2018 to 2022 at a single center. Patient demographics, medical history, seizure characteristics, and treatment outcomes were collected from electronic medical records. Duration of FFA treatment, dosage regimens, seizure frequency, seizure severity, improvements in cognitive, social, and motor outcomes, and adverse events were extracted and analyzed. Effectiveness was assessed using ≥50 % sustained reduction in monthly seizure frequency vs baseline for ≥2 consecutive months at 12 months; seizure freedom was a secondary measure. RESULTS Seizure frequency data was available for 56 of 68 patients included in the study. At 12 months, 50 patients (89.3 %) remained on FFA treatment; 58 % of these patients achieved a ≥50 % sustained response and 10 % experienced seizure freedom. Cognitive, motor, and social improvement were noted in 70.7 %, 36.2 %, and 27.6 % of patients, respectively. The total number of concomitant antiseizure medications was reduced by ≥1 in 29.4 % of patients. No differences were found between DS and LGS patients in these outcomes; age at start of FFA and age at the 12-month timepoint did not have an effect. At least one AE was experienced by 59.7% of patients; in 86.5% of the cases, AEs were plausibly related to treatment. While 70.3% of AEs were self-resolving and 81.8% of the remaining patients experienced mild AEs, 1 patient experienced a serious AE unrelated to FFA which resulted in the patient's death. There were no cases of pulmonary arterial hypertension or ventricular heart disease. SIGNIFICANCE The effectiveness and tolerability of FFA treatment in patients with DS or LGS in this retrospective analysis of real-world data were consistent with those seen in randomized clinical trials.
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Affiliation(s)
| | - Álvaro Beltrán
- Neurology department, Hospital Ruber Internacional, Madrid, Spain.
| | | | | | | | - Ángel Aledo-Serrano
- Neurology department, Hospital Ruber Internacional, Madrid, Spain; Vithas Neuroscience Institute, Madrid Spain
| | - Gloria López Sobrino
- Neurology department, Hospital Ruber Internacional, Madrid, Spain; Hospital Universitario La Paz, Madrid, Spain.
| | - Fernando Ayuga
- Hospital Quirónsalud Toledo, Toledo, Spain; Hospital Universitario de Toledo, Toledo, Spain
| | | | - Antonio Gil-Nagel
- Fundación Iniciativa para las Neurociencias (FINCE), Madrid, Spain; Neurology department, Hospital Ruber Internacional, Madrid, Spain.
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Cha J, Filatov G, Smith SJ, Gammaitoni AR, Lothe A, Reeder T. Fenfluramine increases survival and reduces markers of neurodegeneration in a mouse model of Dravet syndrome. Epilepsia Open 2024; 9:300-313. [PMID: 38018342 PMCID: PMC10839300 DOI: 10.1002/epi4.12873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Accepted: 11/21/2023] [Indexed: 11/30/2023] Open
Abstract
OBJECTIVE In patients with Dravet syndrome (DS), fenfluramine reduced convulsive seizure frequency and provided clinical benefit in nonseizure endpoints (e.g., executive function, survival). In zebrafish mutant scn1 DS models, chronic fenfluramine treatment preserved neuronal cytoarchitecture prior to seizure onset and prevented gliosis; here, we extend these findings to a mammalian model of DS (Scn1a+/- mice) by evaluating the effects of fenfluramine on neuroinflammation (degenerated myelin, activated microglia) and survival. METHODS Scn1a+/- DS mice were treated subcutaneously once daily with fenfluramine (15 mg/kg) or vehicle from postnatal day (PND) 7 until 35-37. Sagittal brain sections were processed for immunohistochemistry using antibodies to degraded myelin basic protein (D-MBP) for degenerated myelin, or CD11b for activated (inflammatory) microglia; sections were scored semi-quantitatively. Apoptotic nuclei were quantified by TUNEL assay. Statistical significance was evaluated by 1-way ANOVA with post-hoc Dunnett's test (D-MBP, CD11b, and TUNEL) or Logrank Mantel-Cox (survival). RESULTS Quantitation of D-MBP immunostaining per 0.1 mm2 unit area of the parietal cortex and hippocampus CA3 yielded significantly higher spheroidal and punctate myelin debris counts in vehicle-treated DS mice than in wild-type mice. Fenfluramine treatment in DS mice significantly reduced these counts. Activated CD11b + microglia were more abundant in DS mouse corpus callosum and hippocampus than in wild-type controls. Fenfluramine treatment of DS mice resulted in significantly fewer activated CD11b + microglia than vehicle-treated DS mice in these brain regions. TUNEL staining in corpus callosum was increased in DS mice relative to wild-type controls. Fenfluramine treatment in DS mice lowered TUNEL staining relative to vehicle-treated DS mice. By PND 35-37, 55% of control DS mice had died, compared with 24% of DS mice receiving fenfluramine treatment (P = 0.0291). SIGNIFICANCE This is the first report of anti-neuroinflammation and pro-survival after fenfluramine treatment in a mammalian DS model. These results corroborate prior data in humans and animal models and suggest important pharmacological activities for fenfluramine beyond seizure reduction. PLAIN LANGUAGE SUMMARY Dravet syndrome is a severe epilepsy disorder that impairs learning and causes premature death. Clinical studies in patients with Dravet syndrome show that fenfluramine reduces convulsive seizures. Additional studies suggest that fenfluramine may have benefits beyond seizures, including promoting survival and improving control over emotions and behavior. Our study is the first to use a Dravet mouse model to investigate nonseizure outcomes of fenfluramine. Results showed that fenfluramine treatment of Dravet mice reduced neuroinflammation significantly more than saline treatment. Fenfluramine-treated Dravet mice also lived longer than saline-treated mice. These results support clinical observations that fenfluramine may have benefits beyond seizures.
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Affiliation(s)
- John Cha
- University of California San FranciscoSan FranciscoCaliforniaUSA
- Zogenix, Inc. (now a part of UCB)EmeryvilleCaliforniaUSA
| | - Gregory Filatov
- Zogenix, Inc. (now a part of UCB)EmeryvilleCaliforniaUSA
- Crosshair Therapeutics, Inc.SunnyvaleCaliforniaUSA
| | - Steven J. Smith
- Zogenix, Inc. (now a part of UCB)EmeryvilleCaliforniaUSA
- WuXi AppTec, Inc.San FranciscoCaliforniaUSA
| | | | | | - Thadd Reeder
- Zogenix, Inc. (now a part of UCB)EmeryvilleCaliforniaUSA
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Whyte-Fagundes P, Vance A, Carroll A, Figueroa F, Manukyan C, Baraban SC. Testing of putative antiseizure drugs in a preclinical Dravet syndrome zebrafish model. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.11.566723. [PMID: 38014342 PMCID: PMC10680609 DOI: 10.1101/2023.11.11.566723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Dravet syndrome (DS) is a severe genetic epilepsy primarily caused by de novo mutations in a voltage-activated sodium channel gene (SCN1A). Patients face life-threatening seizures that are largely resistant to available anti-seizure medications (ASM). Preclinical DS animal models are a valuable tool to identify candidate ASMs for these patients. Among these, scn1lab mutant zebrafish exhibiting spontaneous seizure-like activity are particularly amenable to large-scale drug screening. Prior screening in a scn1lab mutant zebrafish line generated using N-ethyl-Nnitrosourea (ENU) identified valproate, stiripentol, and fenfluramine e.g., Federal Drug Administration (FDA) approved drugs with clinical application in the DS population. Successful phenotypic screening in scn1lab mutant zebrafish consists of two stages: (i) a locomotion-based assay measuring high-velocity convulsive swim behavior and (ii) an electrophysiology-based assay, using in vivo local field potential (LFP) recordings, to quantify electrographic seizure-like events. Using this strategy more than 3000 drug candidates have been screened in scn1lab zebrafish mutants. Here, we curated a list of nine additional anti-seizure drug candidates recently identified in preclinical models: 1-EBIO, AA43279, chlorzoxazone, donepezil, lisuride, mifepristone, pargyline, soticlestat and vorinostat. First-stage locomotion-based assays in scn1lab mutant zebrafish identified only 1-EBIO, chlorzoxazone and lisuride. However, second-stage LFP recording assays did not show significant suppression of spontaneous electrographic seizure activity for any of the nine anti-seizure drug candidates. Surprisingly, soticlestat induced frank electrographic seizure-like discharges in wild-type control zebrafish. Taken together, our results failed to replicate clear anti-seizure efficacy for these drug candidates highlighting a necessity for strict scientific standards in preclinical identification of ASMs.
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Affiliation(s)
- P Whyte-Fagundes
- Epilepsy Research Laboratory and Weill Institute for Neuroscience, Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, USA
| | - A Vance
- Epilepsy Research Laboratory and Weill Institute for Neuroscience, Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, USA
| | - A Carroll
- Behavioral Neurosciences, Northeastern University, Boston, MA, USA
| | - F Figueroa
- Epilepsy Research Laboratory and Weill Institute for Neuroscience, Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, USA
| | - C Manukyan
- Helen Wills Neuroscience Institute, University of California, Berkeley, CA, USA
| | - S C Baraban
- Epilepsy Research Laboratory and Weill Institute for Neuroscience, Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, USA
- Helen Wills Neuroscience Institute, University of California, Berkeley, CA, USA
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