Abstract Details

Title Real-world effectiveness of eculizumab in generalized myasthenia gravis in Japan: 1-year post-marketing surveillance data

Topic Autoimmune Neurology

Presentation(s) S41 - Autoimmune Neurology 3: Autoimmune Encephalitis, Paraneoplastic Neurologic Disorders, Antibody-Mediated Diseases, Immunology (5:06 PM-5:18 PM)

Poster/Presentation
Number 009

Background Eculizumab was approved in Japan in 2017 for treating adults with AChR Ab+ gMG whose symptoms are difficult to control with high-dose intravenous immunoglobulin therapy or plasma exchange.

Objective

To evaluate the real-world effectiveness of eculizumab for treating anti-acetylcholine receptor antibody-positive (AChR Ab+) generalized myasthenia gravis (gMG) in Japan.

Design/Methods Myasthenia Gravis Activities of Daily Living (MG-ADL) scores, Quantitative Myasthenia Gravis (QMG) scores and adverse events (AEs) for all adults with AChR Ab+ gMG treated with eculizumab in Japan were analyzed (interim analysis; data cutoff, April 2021). Treatment response was defined as ≥3-point reduction in MG-ADL total score.

Results In total, 134 patients were included in the safety analysis set and 126 in the effectiveness analysis set. Nearly half (44.0%) had history of thymoma. Clinical improvements with eculizumab were observed through 1 year: mean (standard deviation) changes from baseline in MG-ADL total score were –4.1 (3.5) at week 12 (n=93) and –5.0 (4.2) at 1 year (n=46). Among all patients, MG-ADL responder rates were 66.7% (62/93) at week 12 and 76.1% (35/46) at 1 year; among patients with Myasthenia Gravis Foundation of America (MGFA) class V gMG at baseline (excluded from REGAIN, NCT01997229), MG-ADL responder rates were 71.4% (5/7) at week 12 and 100.0% (6/6) at week 26. Results for QMG were similar to those for MG-ADL. The proportion of patients receiving a daily oral corticosteroid dose of ≤5 mg increased from 7.0% before eculizumab (week –4) to 26.4% at 1 year. No meningococcal infections or new AEs were reported. One patient died during treatment (considered to be unrelated to eculizumab).

Conclusions

Effectiveness of eculizumab for treatment of AChR Ab+ gMG was confirmed to be rapid and sustained in patients observed for 1 year in real-world clinical practice in Japan, including in patients with MGFA class V disease. No new safety signals were observed.

Authors/Disclosures
Hiroyuki Murai, MD (International University of Health and Welfare) PRESENTER	Dr. Murai has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Alexion Pharmaceuticals. Dr. Murai has received personal compensation in the range of $500-$4,999 for serving as a Consultant for argenx. Dr. Murai has received personal compensation in the range of $500-$4,999 for serving as a Consultant for UCB. Dr. Murai has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Chugai Pharmaceutical. The institution of Dr. Murai has received research support from Japan Blood Products Organization.
	No disclosure on file
Yuji Fukamizu	Yuji Fukamizu has received personal compensation for serving as an employee of Alexion Pharma GK.
	No disclosure on file
	No disclosure on file
Kimiaki Utsugisawa, MD, PhD (Hanamaki General Hospital)	Dr. Utsugisawa has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for argenx. Dr. Utsugisawa has received personal compensation in the range of $10,000-$49,999 for serving on a Scientific Advisory or Data Safety Monitoring board for UCB pharma. Dr. Utsugisawa has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Janssen pharma. Dr. Utsugisawa has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Viela Bio. Dr. Utsugisawa has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Chugai. Dr. Utsugisawa has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Mitsubisi Tanabe pharma. Dr. Utsugisawa has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Merck. Dr. Utsugisawa has received personal compensation in the range of $5,000-$9,999 for serving on a Speakers Bureau for argenx. Dr. Utsugisawa has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Alexion phama. Dr. Utsugisawa has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Japan Blood Products Organization. Dr. Utsugisawa has received personal compensation in the range of $5,000-$9,999 for serving on a Speakers Bureau for UCB.