Randomized Trial of Thymectomy in Myasthenia Gravis
Gil I Wolfe, Henry J Kaminski, Inmaculada B Aban, Greg Minisman, Hui-Chien Kuo, Alexander Marx, Philipp Ströbel, Claudio Mazia, Joel Oger, J Gabriel Cea, Jeannine M Heckmann, Amelia Evoli, Wilfred Nix, Emma Ciafaloni, Giovanni Antonini, Rawiphan Witoonpanich, John O King, Said R Beydoun, Colin H Chalk, Alexandru C Barboi, Anthony A Amato, Aziz I Shaibani, Bashar Katirji, Bryan R F Lecky, Camilla Buckley, Angela Vincent, Elza Dias-Tosta, Hiroaki Yoshikawa, Márcia Waddington-Cruz, Michael T Pulley, Michael H Rivner, Anna Kostera-Pruszczyk, Robert M Pascuzzi, Carlayne E Jackson, Guillermo S Garcia Ramos, Jan J G M Verschuuren, Janice M Massey, John T Kissel, Lineu C Werneck, Michael Benatar, Richard J Barohn, Rup Tandan, Tahseen Mozaffar, Robin Conwit, Joanne Odenkirchen, Joshua R Sonett, Alfred Jaretzki 3rd, John Newsom-Davis, Gary R Cutter, MGTX Study Group
Abstract
Background: Thymectomy has been a mainstay in the treatment of myasthenia gravis, but there is no conclusive evidence of its benefit. We conducted a multicenter, randomized trial comparing thymectomy plus prednisone with prednisone alone.
Methods: We compared extended transsternal thymectomy plus alternate-day prednisone with alternate-day prednisone alone. Patients 18 to 65 years of age who had generalized nonthymomatous myasthenia gravis with a disease duration of less than 5 years were included if they had Myasthenia Gravis Foundation of America clinical class II to IV disease (on a scale from I to V, with higher classes indicating more severe disease) and elevated circulating concentrations of acetylcholine-receptor antibody. The primary outcomes were the time-weighted average Quantitative Myasthenia Gravis score (on a scale from 0 to 39, with higher scores indicating more severe disease) over a 3-year period, as assessed by means of blinded rating, and the time-weighted average required dose of prednisone over a 3-year period.
Results: A total of 126 patients underwent randomization between 2006 and 2012 at 36 sites. Patients who underwent thymectomy had a lower time-weighted average Quantitative Myasthenia Gravis score over a 3-year period than those who received prednisone alone (6.15 vs. 8.99, P<0.001); patients in the thymectomy group also had a lower average requirement for alternate-day prednisone (44 mg vs. 60 mg, P<0.001). Fewer patients in the thymectomy group than in the prednisone-only group required immunosuppression with azathioprine (17% vs. 48%, P<0.001) or were hospitalized for exacerbations (9% vs. 37%, P<0.001). The number of patients with treatment-associated complications did not differ significantly between groups (P=0.73), but patients in the thymectomy group had fewer treatment-associated symptoms related to immunosuppressive medications (P<0.001) and lower distress levels related to symptoms (P=0.003).
Conclusions: Thymectomy improved clinical outcomes over a 3-year period in patients with nonthymomatous myasthenia gravis. (Funded by the National Institute of Neurological Disorders and Stroke and others; MGTX ClinicalTrials.gov number, NCT00294658.).
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Source: PubMed