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Brickel N, Hewett K, Rayner K, McDonald S, De'Ath J, Daniluk J, Joshi K, Boll MC, Tiamkao S, Vorobyeva O, Cooper J. Safety of retigabine in adults with partial-onset seizures after long-term exposure: focus on unexpected ophthalmological and dermatological events. Epilepsy Behav 2020; 102:106580. [PMID: 31731109 DOI: 10.1016/j.yebeh.2019.106580] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 09/18/2019] [Accepted: 09/19/2019] [Indexed: 12/30/2022]
Abstract
BACKGROUND Retigabine is an antiepileptic drug developed for the adjunctive treatment of adults with epilepsy and partial-onset seizures (POS). Following its approval in 2011, reports of ophthalmological/dermatological pigmentation/discoloration led to a restriction of the indication in 2013, and in 2017, retigabine was voluntarily withdrawn from the market because of its limited usage. Here, data are reported from four open-label extension studies focusing on long-term safety with particular emphasis on ophthalmological and dermatological events. METHODS Studies 113413 (NCT01336621), 114873 (NCT01777139), 115097 (NCT00310388), and 115098 (NCT00310375) were multicenter, open-label extension studies of retigabine (300-1200 mg/day) for the adjunctive treatment of adults with POS. Safety assessments included monitoring treatment-emergent adverse events (TEAEs) and serious adverse events (SAEs). When new safety issues were identified, protocols were amended to include additional on-treatment safety evaluations, including ophthalmological and dermatological examinations. Patients who had abnormal retinal pigmentation, unexplained vision change, pigmentation of nonretinal ocular tissue, or abnormal discoloration of skin, lips, nails, and/or mucosa at the end of the treatment phase were asked to enter a safety follow-up continuation phase comprising 6-monthly ophthalmological/dermatological assessments. RESULTS The safety population (patients receiving ≥1 dose of retigabine in the open-label phase) comprised 98, 30, 376, and 181 patients for studies 113413, 114873, 115097, and 115098, respectively. Mean (standard deviation) treatment exposure ranged from 529 (424) to 1129 (999) days. In total, 68%-96% and 4%-27% of patients across the studies experienced TEAEs and TE SAEs, respectively. There were seven on-treatment deaths and two after discontinuation. Overall, 14%-73% of patients had an on-treatment eye examination, of whom 8/53, 4/22, 17/54, and 14/36 had abnormal retinal pigmentation and 15/53, 7/22, 15/54, and 11/36 had nonretinal ocular pigmentation in studies 113413, 114873, 115097, and 115098, respectively. Four patients had confirmed acquired vitelliform maculopathy. In patients with unresolved events at discontinuation and ≥1 posttreatment follow-up, retinal pigmentation resolved completely in 1/3, 0/3, 0/10, and 1/7 patients and nonretinal ocular pigmentation in 1/4, 0/3, 8/10, and 4/6 patients, respectively. Overall, 12%-83% of patients had an on-treatment dermatological examination, of whom 11/58, 0/25, 23/46, and 23/37 had any-tissue discoloration, respectively. In patients with unresolved events at discontinuation and ≥1 posttreatment follow-up, discoloration of skin, lips, nails, and/or mucosa resolved completely in 2/3, 0/0, 7/13, and 1/11 patients, respectively. CONCLUSIONS The safety profile of retigabine in adults with POS across four open-label studies was generally consistent with data from previous placebo-controlled studies. Discoloration of various tissues occurred in a proportion of patients treated with retigabine and resolved completely in a small number of these patients following treatment discontinuation. In addition, comprehensive eye examination identified a new adverse reaction of acquired vitelliform maculopathy in a limited number of patients.
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Affiliation(s)
| | | | - Kirsty Rayner
- Probabilitas Consulting Limited, Berkhamsted, Hertfordshire, UK
| | | | | | | | | | - Marie Catherine Boll
- Instituto Nacional de Neurologia y Neurocirugia "Manuel Velasco Suarez", Tlalpan, Mexico
| | - Somsak Tiamkao
- Division of Neurology, Department of Medicine, Faculty of Medicine, Integrated Epilepsy Research Group, Khon Kaen University, Thailand
| | - Olga Vorobyeva
- Central Clinical Hospital #2 OAO RZD, Rehabilitation Department, Moscow, Russia; IM Sechenov First Moscow State Medical University (Sechenovskiy University), Ministry of Health, Russia
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Fureman BE, Friedman D, Baulac M, Glauser T, Moreno J, Dixon-Salazar T, Bagiella E, Connor J, Ferry J, Farrell K, Fountain NB, French JA. Reducing placebo exposure in trials: Considerations from the Research Roundtable in Epilepsy. Neurology 2017; 89:1507-1515. [PMID: 28878049 DOI: 10.1212/wnl.0000000000004535] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2017] [Accepted: 07/10/2017] [Indexed: 11/15/2022] Open
Abstract
The randomized controlled trial is the unequivocal gold standard for demonstrating clinical efficacy and safety of investigational therapies. Recently there have been concerns raised about prolonged exposure to placebo and ineffective therapy during the course of an add-on regulatory trial for new antiepileptic drug approval (typically ∼6 months in duration), due to the potential risks of continued uncontrolled epilepsy for that period. The first meeting of the Research Roundtable in Epilepsy on May 19-20, 2016, focused on "Reducing placebo exposure in epilepsy clinical trials," with a goal of considering new designs for epilepsy regulatory trials that may be added to the overall development plan to make it, as a whole, safer for participants while still providing rigorous evidence of effect. This topic was motivated in part by data from a meta-analysis showing a 3- to 5-fold increased rate of sudden unexpected death in epilepsy in participants randomized to placebo or ineffective doses of new antiepileptic drugs. The meeting agenda included rationale and discussion of different trial designs, including active-control add-on trials, placebo add-on to background therapy with adjustment, time to event designs, adaptive designs, platform trials with pooled placebo control, a pharmacokinetic/pharmacodynamic approach to reducing placebo exposure, and shorter trials when drug tolerance has been ruled out. The merits and limitations of each design were discussed and are reviewed here.
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Affiliation(s)
- Brandy E Fureman
- From the Research and New Therapies Program (B.E.F., K.F., J.A.F.), Epilepsy Foundation of America, Landover, MD; Department of Neurology (D.F., J.A.F.), New York University, New York; Department of Neurology (M.B.), Hôpital la Salpêtrière, APHP/ICM, University Pierre et Marie Curie, Paris, France; Cincinnati Children's Research Foundation (T.G.), OH; University of Pennsylvania (J.M.), Philadelphia; LGS Foundation (Lennox-Gastaut Syndrome) (T.D.-S.), Bohemia; Mount Sinai School of Medicine (E.B.), New York, NY; Berry Consultants LLC and University of Central Florida College of Medicine (J.C.), Orlando; Eisai Inc. (J.F.), Woodcliff Lake, NJ; and Department of Neurology (N.B.F.), University of Virginia, Charlottesville.
| | - Daniel Friedman
- From the Research and New Therapies Program (B.E.F., K.F., J.A.F.), Epilepsy Foundation of America, Landover, MD; Department of Neurology (D.F., J.A.F.), New York University, New York; Department of Neurology (M.B.), Hôpital la Salpêtrière, APHP/ICM, University Pierre et Marie Curie, Paris, France; Cincinnati Children's Research Foundation (T.G.), OH; University of Pennsylvania (J.M.), Philadelphia; LGS Foundation (Lennox-Gastaut Syndrome) (T.D.-S.), Bohemia; Mount Sinai School of Medicine (E.B.), New York, NY; Berry Consultants LLC and University of Central Florida College of Medicine (J.C.), Orlando; Eisai Inc. (J.F.), Woodcliff Lake, NJ; and Department of Neurology (N.B.F.), University of Virginia, Charlottesville
| | - Michel Baulac
- From the Research and New Therapies Program (B.E.F., K.F., J.A.F.), Epilepsy Foundation of America, Landover, MD; Department of Neurology (D.F., J.A.F.), New York University, New York; Department of Neurology (M.B.), Hôpital la Salpêtrière, APHP/ICM, University Pierre et Marie Curie, Paris, France; Cincinnati Children's Research Foundation (T.G.), OH; University of Pennsylvania (J.M.), Philadelphia; LGS Foundation (Lennox-Gastaut Syndrome) (T.D.-S.), Bohemia; Mount Sinai School of Medicine (E.B.), New York, NY; Berry Consultants LLC and University of Central Florida College of Medicine (J.C.), Orlando; Eisai Inc. (J.F.), Woodcliff Lake, NJ; and Department of Neurology (N.B.F.), University of Virginia, Charlottesville
| | - Tracy Glauser
- From the Research and New Therapies Program (B.E.F., K.F., J.A.F.), Epilepsy Foundation of America, Landover, MD; Department of Neurology (D.F., J.A.F.), New York University, New York; Department of Neurology (M.B.), Hôpital la Salpêtrière, APHP/ICM, University Pierre et Marie Curie, Paris, France; Cincinnati Children's Research Foundation (T.G.), OH; University of Pennsylvania (J.M.), Philadelphia; LGS Foundation (Lennox-Gastaut Syndrome) (T.D.-S.), Bohemia; Mount Sinai School of Medicine (E.B.), New York, NY; Berry Consultants LLC and University of Central Florida College of Medicine (J.C.), Orlando; Eisai Inc. (J.F.), Woodcliff Lake, NJ; and Department of Neurology (N.B.F.), University of Virginia, Charlottesville
| | - Jonathan Moreno
- From the Research and New Therapies Program (B.E.F., K.F., J.A.F.), Epilepsy Foundation of America, Landover, MD; Department of Neurology (D.F., J.A.F.), New York University, New York; Department of Neurology (M.B.), Hôpital la Salpêtrière, APHP/ICM, University Pierre et Marie Curie, Paris, France; Cincinnati Children's Research Foundation (T.G.), OH; University of Pennsylvania (J.M.), Philadelphia; LGS Foundation (Lennox-Gastaut Syndrome) (T.D.-S.), Bohemia; Mount Sinai School of Medicine (E.B.), New York, NY; Berry Consultants LLC and University of Central Florida College of Medicine (J.C.), Orlando; Eisai Inc. (J.F.), Woodcliff Lake, NJ; and Department of Neurology (N.B.F.), University of Virginia, Charlottesville
| | - Tracy Dixon-Salazar
- From the Research and New Therapies Program (B.E.F., K.F., J.A.F.), Epilepsy Foundation of America, Landover, MD; Department of Neurology (D.F., J.A.F.), New York University, New York; Department of Neurology (M.B.), Hôpital la Salpêtrière, APHP/ICM, University Pierre et Marie Curie, Paris, France; Cincinnati Children's Research Foundation (T.G.), OH; University of Pennsylvania (J.M.), Philadelphia; LGS Foundation (Lennox-Gastaut Syndrome) (T.D.-S.), Bohemia; Mount Sinai School of Medicine (E.B.), New York, NY; Berry Consultants LLC and University of Central Florida College of Medicine (J.C.), Orlando; Eisai Inc. (J.F.), Woodcliff Lake, NJ; and Department of Neurology (N.B.F.), University of Virginia, Charlottesville
| | - Emilia Bagiella
- From the Research and New Therapies Program (B.E.F., K.F., J.A.F.), Epilepsy Foundation of America, Landover, MD; Department of Neurology (D.F., J.A.F.), New York University, New York; Department of Neurology (M.B.), Hôpital la Salpêtrière, APHP/ICM, University Pierre et Marie Curie, Paris, France; Cincinnati Children's Research Foundation (T.G.), OH; University of Pennsylvania (J.M.), Philadelphia; LGS Foundation (Lennox-Gastaut Syndrome) (T.D.-S.), Bohemia; Mount Sinai School of Medicine (E.B.), New York, NY; Berry Consultants LLC and University of Central Florida College of Medicine (J.C.), Orlando; Eisai Inc. (J.F.), Woodcliff Lake, NJ; and Department of Neurology (N.B.F.), University of Virginia, Charlottesville
| | - Jason Connor
- From the Research and New Therapies Program (B.E.F., K.F., J.A.F.), Epilepsy Foundation of America, Landover, MD; Department of Neurology (D.F., J.A.F.), New York University, New York; Department of Neurology (M.B.), Hôpital la Salpêtrière, APHP/ICM, University Pierre et Marie Curie, Paris, France; Cincinnati Children's Research Foundation (T.G.), OH; University of Pennsylvania (J.M.), Philadelphia; LGS Foundation (Lennox-Gastaut Syndrome) (T.D.-S.), Bohemia; Mount Sinai School of Medicine (E.B.), New York, NY; Berry Consultants LLC and University of Central Florida College of Medicine (J.C.), Orlando; Eisai Inc. (J.F.), Woodcliff Lake, NJ; and Department of Neurology (N.B.F.), University of Virginia, Charlottesville
| | - Jim Ferry
- From the Research and New Therapies Program (B.E.F., K.F., J.A.F.), Epilepsy Foundation of America, Landover, MD; Department of Neurology (D.F., J.A.F.), New York University, New York; Department of Neurology (M.B.), Hôpital la Salpêtrière, APHP/ICM, University Pierre et Marie Curie, Paris, France; Cincinnati Children's Research Foundation (T.G.), OH; University of Pennsylvania (J.M.), Philadelphia; LGS Foundation (Lennox-Gastaut Syndrome) (T.D.-S.), Bohemia; Mount Sinai School of Medicine (E.B.), New York, NY; Berry Consultants LLC and University of Central Florida College of Medicine (J.C.), Orlando; Eisai Inc. (J.F.), Woodcliff Lake, NJ; and Department of Neurology (N.B.F.), University of Virginia, Charlottesville
| | - Kathleen Farrell
- From the Research and New Therapies Program (B.E.F., K.F., J.A.F.), Epilepsy Foundation of America, Landover, MD; Department of Neurology (D.F., J.A.F.), New York University, New York; Department of Neurology (M.B.), Hôpital la Salpêtrière, APHP/ICM, University Pierre et Marie Curie, Paris, France; Cincinnati Children's Research Foundation (T.G.), OH; University of Pennsylvania (J.M.), Philadelphia; LGS Foundation (Lennox-Gastaut Syndrome) (T.D.-S.), Bohemia; Mount Sinai School of Medicine (E.B.), New York, NY; Berry Consultants LLC and University of Central Florida College of Medicine (J.C.), Orlando; Eisai Inc. (J.F.), Woodcliff Lake, NJ; and Department of Neurology (N.B.F.), University of Virginia, Charlottesville
| | - Nathan B Fountain
- From the Research and New Therapies Program (B.E.F., K.F., J.A.F.), Epilepsy Foundation of America, Landover, MD; Department of Neurology (D.F., J.A.F.), New York University, New York; Department of Neurology (M.B.), Hôpital la Salpêtrière, APHP/ICM, University Pierre et Marie Curie, Paris, France; Cincinnati Children's Research Foundation (T.G.), OH; University of Pennsylvania (J.M.), Philadelphia; LGS Foundation (Lennox-Gastaut Syndrome) (T.D.-S.), Bohemia; Mount Sinai School of Medicine (E.B.), New York, NY; Berry Consultants LLC and University of Central Florida College of Medicine (J.C.), Orlando; Eisai Inc. (J.F.), Woodcliff Lake, NJ; and Department of Neurology (N.B.F.), University of Virginia, Charlottesville
| | - Jacqueline A French
- From the Research and New Therapies Program (B.E.F., K.F., J.A.F.), Epilepsy Foundation of America, Landover, MD; Department of Neurology (D.F., J.A.F.), New York University, New York; Department of Neurology (M.B.), Hôpital la Salpêtrière, APHP/ICM, University Pierre et Marie Curie, Paris, France; Cincinnati Children's Research Foundation (T.G.), OH; University of Pennsylvania (J.M.), Philadelphia; LGS Foundation (Lennox-Gastaut Syndrome) (T.D.-S.), Bohemia; Mount Sinai School of Medicine (E.B.), New York, NY; Berry Consultants LLC and University of Central Florida College of Medicine (J.C.), Orlando; Eisai Inc. (J.F.), Woodcliff Lake, NJ; and Department of Neurology (N.B.F.), University of Virginia, Charlottesville
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