Association of baseline acetylcholine receptor antibody levels with efgartigimod treatment efficacy for patients with myasthenia gravis.

BACKGROUND

Efgartigimod is effective for many patients with acetylcholine receptor (AChR) antibody-positive generalized myasthenia gravis (gMG). To help identify patients most likely to benefit from efgartigimod, we examined the correlation between baseline AChR antibody levels and clinical response.

METHODS

This retrospective observational study included 10 AChR antibody-positive MG patients receiving efgartigimod at a single center. Clinical responses were assessed by MG Activities of Daily Living (MG-ADL) scores before treatment as well as 15 and 29 days after treatment initiation.

RESULTS

Patients demonstrated clinical improvement by day 15 as indicated by improved total MG-ADL score (mean, 3.6; range, -1 to 9; p = 0.0055), and condition improved further by day 29 (mean, 5.2; range, 2-10; p = 0.0003). Serum AChR antibody levels at baseline were positively correlated with MG-ADL score improvement on day 29 (r = 0.6483, p = 0.0426).

CONCLUSIONS

Generalized MG patients with high baseline AChR antibody levels may exhibit a superior response to efgartigimod.