Response to eculizumab in patients with myasthenia gravis recently treated with chronic IVIg: a subgroup analysis of REGAIN and its open-label extension study
Authors: Jacob Saiju , Murai Hiroyuki , Utsugisawa Kimiaki , Nowak Richard J. , Wiendl Heinz , Fujita Kenji P. , O’Brien Fanny , Howard James F. , Mazia Claudio Gabriel , Wilken Miguel , Barroso Fabio , Saba Juliet , De Bleecker Jan , Van den Abeele Guy , de Koning Kathy , De Mey Katrien , Carvalho Alzira Alves de Siqueira , Brockhausen Igor Dias , Feder David , Ambrosio Daniel , César Pamela , Melo Ana Paula , Ribeiro Renata Martins , Rocha Rosana , Rosa Bruno Bezerra , Veiga Thabata , da Silva Luiz Augusto , Engel Murilo Santos , Gonçalves Geraldo Jordana , Nagane Yuriko , Kamegamori Ikuko , Tsuda Tomoko , Fujii Yuko , Futono Kazumi , Ozawa Yukiko , Mizugami Aya , Saito Yuka , van der Kooi Anneke , de Visser Marianne , Gibson Tamar , Kim Seung Min , Jeong JinWoo , Jung Ha-Neul , Kim Yool-hee , Lee Hyung Seok , Shin Ha Young , Hwang Eun Bi , Shin Miju , Carbonell Josep Gamez , Sune Pilar , Figueras Maria Salvado , Gili Gisela , Mazuela Gonzalo , Piehl Fredrik , Hietala Albert , Bjarbo Lena , Erdem-Ozdamar Sevim , Bekircan-Kurt Can Ebru , Acar Nazire Pinar , Yilmaz Ezgi , Caliskan Yagmur , Orsel Gulsah , Amato Anthony , Cochrane Thomas , Salajegheh Mohammed , Roe Kristen , Amato Katherine , Toska Shirli , McKinnon Jonathan , Haar Laura , McKinnon Naya , Alcon Karan , McKenna Kaitlyn , Sattar Nadia , Daniels Kevin , Jeffery Dennis , Mozaffar Tahseen , Cash Tiyonnoh , Goyal Namita , Roy Gulmohor , Mathew Veena , Maqsood Fatima , Minton Brian , Hafer-Macko Charlene , Kwan Justin , Zilliox Lindsay , Callison Karen , Young Valerie , DiSanzo Beth , Naunton Kerry , Vu Tuan , Katzin Lara , McClain Terry , Harvey Brittany , Hart Adam , Huynh Kristin , Beydoun Said , Chilingaryan Amaiak , Doan Victor , Droker Brian , Gong Hui , Karimi Sanaz , Lin Frank , McClain Terry , Polaka Krishna , Shah Akshay , Tran Anh , Akhter Salma , Malekniazi Ali , Tandan Rup , Hehir Michael , Waheed Waqar , Lucy Shannon , Bertorini Tulio , Arnold Thomas , Hendersen Kendrick , Pillai Rekha , Liu Ye , Wheeler Lauren , Hewlett Jasmine , Vanderhook Mollie 
Published: May 2020

Background: In the phase III eculizumab for refractory generalized myasthenia gravis REGAIN study [ClinicalTrials.gov identifier: NCT01997229] and its open-label extension (OLE) [ClinicalTrials.gov identifier: NCT02301624], patients with treatment-refractory antiacetylcholine receptor antibody-positive generalized myasthenia gravis had clinically meaningful improvements with eculizumab versus placebo. This subgroup analysis evaluated data from patients with a recent history of chronic intravenous immunoglobulin (IVIg) use before study entry. Methods: The subgroup comprised patients who had received IVIg at least four times in 1 year, with at least one IVIg treatment cycle during the 6 months before the first REGAIN study dose. Data from REGAIN and the OLE were analyzed. Response to eculizumab versus placebo was assessed using four validated, disease-specific measures. Incidences of exacerbations and safety endpoints were recorded. Results: The subgroup had similar patient and disease characteristics as the overall REGAIN population. Clinical assessments showed sustained eculizumab efficacy during REGAIN and the OLE over 18 months. Patients receiving placebo in REGAIN experienced rapid improvements in assessment scores when treated with eculizumab in the OLE. There was a lower rate of disease exacerbations with eculizumab than with placebo during REGAIN, and eculizumab was well tolerated. Conclusion: Eculizumab treatment, compared with placebo, results in meaningful clinical improvements and fewer disease exacerbations for patients who previously received chronic IVIg. Trial registration: REGAIN [ClinicalTrials.gov identifier: NCT01997229]; REGAIN open-label extension [ClinicalTrials.gov identifier: NCT02301624].