To estimate the incidence of clinical deteriorations and healthcare resource utilization (HCRU) among patients with AChR-Ab+ generalized myasthenia gravis (gMG) who switched from efgartigimod to ravulizumab.

Despite the availability of newer biologics, gMG remains suboptimally controlled in many patients receiving conventional immunosuppressants and oral corticosteroids (OCS). Efgartigimod (FcRn-antagonist) and ravulizumab ( C5-inhibitor) have distinct mechanisms of action, and switching between these therapies occurs in clinical practice when symptoms, exacerbations, or dependence on oral corticosteroids (OCS) persist. Real-world evidence evaluating outcomes during these transitions remains limited.

This was a retrospective cohort study using Veeva Compass US claims data of adults with gMG who transitioned from efgartigimod to ravulizumab. Outcomes included gMG exacerbations, OCS dose escalations, and several HCRU endpoints. Incidence rates were compared across three periods: conventional therapy period (“baseline”), efgartigimod period (pre-switch), and ravulizumab period (post-switch). Multivariable-adjusted generalized estimating equations were used to estimate incidence rate ratios (IRRs).

We identified 107 eligible patients with median follow-up of 19, 13, and 14 months during baseline, efgartigimod, and ravulizumab periods, respectively. After initiation of efgartigimod, there were no differences versus baseline in rates of MG exacerbation (IRR=0.63 [0.33-1.19]; p=0.152) or OCS dose escalation (IRR=1.09 [0.81-1.47]; p=0.561). After switching from efgartigimod to ravulizumab, gMG exacerbation rates decreased by 60% (IRR=0.40 [0.20-0.80]; p=0.009) and OCS dose escalation rates decreased by 55% (IRR=0.45 [0.31-0.65]; p<0.001). Similar reductions were observed for Emergency Department encounters and total inpatient days. Neurology outpatient visits increased by 38% during the efgartigimod period (IRR=1.38 [1.06-1.80]; p=0.018) followed by a 63% reduction after switching to ravulizumab (IRR=0.37 [0.28-0.48];p<0.001).

Patients with gMG experienced reductions in clinical deteriorations and HCRU following a switch from efgartigimod to ravulizumab. These findings suggest that complement inhibition with ravulizumab may reduce disease burden and HCRU in patients with gMG previously treated with efgartigimod.