Objective:

To describe real-world treatment outcomes in patients with anti-acetylcholine receptor antibody-positive generalized myasthenia gravis (AChR+ gMG) who transitioned from efgartigimod to ravulizumab.

Background:

While neonatal Fc receptor (FcRn) inhibitors and complement component C5 inhibitor therapies (C5IT) have both demonstrated efficacy in treating AChR+ gMG, real-world data is needed to inform clinical decision-making on how to transition patients between biologic therapies.

Design/Methods:

This case series report leveraged physician-reported electronic medical records to detail real-world treatment outcomes from four adult patients with AChR+ gMG who transitioned from efgartigimod (FcRn inhibition) to ravulizumab (C5IT). Myasthenia Gravis Activities of Daily Living (MG-ADL) scores and Myasthenia Gravis Foundation of America (MGFA) class were used to assess treatment efficacy. Tapering of concomitant corticosteroid therapy was also assessed.

Results:

Prior to efgartigimod initiation, median MG-ADL was 12 (range, 10 – 13) and median MGFA class was MGFA IIIa (range, MGFA IIb – IIIa). Median MG-ADL and MGFA class remained unchanged in all patients after three cycles of efgartigimod (median, 21 weeks; range, 20 – 22 weeks). Due to this lack of response, all patients transitioned to ravulizumab. After transitioning to ravulizumab, median MG-ADL improved to 2 (range, 1 – 2) and median MGFA class improved to MGFA I (range, MGFA I – IIa) at final follow-up (median, 98 weeks on ravulizumab; range, 96 – 100 weeks). All patients were on concomitant corticosteroid therapy with efgartigimod (median, 22.5 mg/d; range, 20 – 30 mg/d), but were able to decrease to 10 mg/d or less (median; 8.75 mg/d; range, 5 – 10 mg/d) at final follow-up. All patients remain well-controlled on ravulizumab. One patient was previously unable to work but returned to work full-time after transitioning to ravulizumab.

Conclusions:

All patients experienced early and sustained improvement upon transitioning from efgartigimod to ravulizumab and were thus able to decrease concomitant corticosteroid use.