“Introduction
Minimal symptom expression (MSE), defined as Myasthenia Gravis Activities of Daily Living (MG-ADL) total score 0 or 1, is explored as a novel proposed treatment target in generalized MG.

Objective
Assess incidence, characteristics, and changes in other MG-specific scales in participants achieving MSE in ADAPT (phase 3 study of efgartigimod IV) and ADAPT+ (open-label extension).

Methods
Post-hoc analyses of ADAPT (n=129) and ADAPT+ (n=111).

Results
In AChR-Ab+ participants from ADAPT, 44.6% treated with efgartigimod achieved MSE vs 10.9% of participants given placebo. In ADAPT+, 40.5% of AChR-Ab+ participants achieved MSE. 81% of participants from efgartigimod treatment arm who achieved MSE in ADAPT continued to achieve MSE during ADAPT+; 23% who had not achieved MSE in ADAPT did in ADAPT+. Baseline characteristics for efgartigimod-treated participants who achieved MSE during ADAPT were comparable to those who did not. Although mean (SD) baseline MG-ADL score was statistically significantly lower for those achieving MSE vs not (8.2 [1.8] vs 9.7 [2.7]), difference was not clinically meaningful. Achieving MSE was associated with substantial improvements in Quantitative Myasthenia Gravis (QMG) and Myasthenia Gravis Quality of Life (MG-QoL15r) mean scores: 11.4-point and 12.4-point decreases, respectively, from baseline to best score (across all visits). For QMG, the difference was ~4 times the threshold for clinically meaningful improvement (≥3 points). An increase of 28 points in EuroQoL-5 Dimensions-5 Levels visual analog score was also seen. MSE achievement resulted in QoL comparable to healthy populations.

Conclusion
Participants who achieved MSE had substantial improvement across multiple disease measures and experienced QoL comparable to healthy populations.”