Randomized phase 2 study of FcRn antagonist efgartigimod in generalized myasthenia gravis
Citation Manager Formats
Make Comment
See Comments

This article requires a subscription to view the full text. If you have a subscription you may use the login form below to view the article. Access to this article can also be purchased.
Abstract
Objective To investigate safety and explore efficacy of efgartigimod (ARGX-113), an anti-neonatal Fc receptor immunoglobulin G1 Fc fragment, in patients with generalized myasthenia gravis (gMG) with a history of anti-acetylcholine receptor (AChR) autoantibodies, who were on stable standard-of-care myasthenia gravis (MG) treatment.
Methods A phase 2, exploratory, randomized, double-blind, placebo-controlled, 15-center study is described. Eligible patients were randomly assigned (1:1) to receive 4 doses over a 3-week period of either 10 mg/kg IV efgartigimod or matched placebo combined with their standard-of-care therapy. Primary endpoints were safety and tolerability. Secondary endpoints included efficacy (change from baseline to week 11 of Myasthenia Gravis Activities of Daily Living, Quantitative Myasthenia Gravis, and Myasthenia Gravis Composite disease severity scores, and of the revised 15-item Myasthenia Gravis Quality of Life scale), pharmacokinetics, pharmacodynamics, and immunogenicity.
Results Of the 35 screened patients, 24 were enrolled and randomized: 12 received efgartigimod and 12 placebo. Efgartigimod was well-tolerated in all patients, with no serious or severe adverse events reported, no relevant changes in vital signs or ECG findings observed, and no difference in adverse events between efgartigimod and placebo treatment. All patients treated with efgartigimod showed a rapid decrease in total immunoglobulin G (IgG) and anti-AChR autoantibody levels, and assessment using all 4 efficacy scales consistently demonstrated that 75% showed a rapid and long-lasting disease improvement.
Conclusions Efgartigimod was safe and well-tolerated. The correlation between reduction of levels of pathogenic IgG autoantibodies and disease improvement suggests that reducing pathogenic autoantibodies with efgartigimod may offer an innovative approach to treat MG.
Classification of evidence This study provides Class I evidence that efgartigimod is safe and well-tolerated in patients with gMG.
Glossary
- AChR=
- acetylcholine receptor;
- ADA=
- antidrug antibody;
- AE=
- adverse event;
- CI=
- confidence interval;
- Cmax=
- maximum observed plasma concentration;
- FcRn=
- neonatal Fc receptor;
- gMG=
- generalized myasthenia gravis;
- IgG=
- immunoglobulin G;
- IVIg=
- IV immunoglobulin;
- IWRS=
- Interactive Web Response System;
- MedDRA=
- Medical Dictionary for Regulatory Authorities;
- MG=
- myasthenia gravis;
- MG-ADL=
- Myasthenia Gravis Activities of Daily Living;
- MG-QoL15r=
- revised 15-item Myasthenia Gravis Quality of Life scale;
- MGC=
- Myasthenia Gravis Composite;
- MGFA=
- Myasthenia Gravis Foundation of America;
- MMRM=
- mixed-model repeated measures;
- QMG=
- Quantitative Myasthenia Gravis;
- Rac=
- accumulation ratio;
- SAE=
- serious adverse event;
- TEAE=
- treatment-emergent adverse event;
- tmax=
- time at maximum observed plasma concentration
Footnotes
Go to Neurology.org/N for full disclosures. Funding information and disclosures deemed relevant by the authors, if any, are provided at the end of the article.
Editorial, page 1079
Class of Evidence: NPub.org/coe
- Received May 28, 2018.
- Accepted in final form January 31, 2019.
- © 2019 American Academy of Neurology
AAN Members
We have changed the login procedure to improve access between AAN.com and the Neurology journals. If you are experiencing issues, please log out of AAN.com and clear history and cookies. (For instructions by browser, please click the instruction pages below). After clearing, choose preferred Journal and select login for AAN Members. You will be redirected to a login page where you can log in with your AAN ID number and password. When you are returned to the Journal, your name should appear at the top right of the page.
AAN Non-Member Subscribers
Purchase access
For assistance, please contact:
AAN Members (800) 879-1960 or (612) 928-6000 (International)
Non-AAN Member subscribers (800) 638-3030 or (301) 223-2300 option 3, select 1 (international)
Sign Up
Information on how to subscribe to Neurology and Neurology: Clinical Practice can be found here
Purchase
Individual access to articles is available through the Add to Cart option on the article page. Access for 1 day (from the computer you are currently using) is US$ 39.00. Pay-per-view content is for the use of the payee only, and content may not be further distributed by print or electronic means. The payee may view, download, and/or print the article for his/her personal, scholarly, research, and educational use. Distributing copies (electronic or otherwise) of the article is not allowed.
Disputes & Debates: Rapid online correspondence
NOTE: All authors' disclosures must be entered and current in our database before comments can be posted. Enter and update disclosures at http://submit.neurology.org. Exception: replies to comments concerning an article you originally authored do not require updated disclosures.
- Stay timely. Submit only on articles published within the last 8 weeks.
- Do not be redundant. Read any comments already posted on the article prior to submission.
- 200 words maximum.
- 5 references maximum. Reference 1 must be the article on which you are commenting.
- 5 authors maximum. Exception: replies can include all original authors of the article.
- Submitted comments are subject to editing and editor review prior to posting.