The efficacy and safety of FcRn inhibitors in patients with myasthenia gravis: a systematic review and meta-analysis

Myasthenia gravis (MG) is an autoimmune disease that causes local or generalized muscle weakness. Complement inhibitors and targeting of the neonatal Fc receptor (FcRn) to block IgG cycling are two novel and successful mechanisms.

PubMed, EMBASE, the Cochrane Library, and ClinicalTrials.gov were systematically searched to identify relevant studies published before May 18, 2023. Review Manager 5.3 software was used to assess the data.

We pooled 532 participants from six randomized controlled trials (RCTs). Compared to the placebo, the FcRn inhibitors were more efficacy in Myasthenia Gravis Activities of Daily Living (MG-ADL) (MD = − 1.69 [− 2.35, − 1.03], P < 0.00001), MG-ADL responder (RR = 2.01 [1.62, 2.48], P < 0.00001), Quantitative Myasthenia Gravis (QMG) (MD = − 2.45 [− 4.35, − 0.55], P = 0.01), Myasthenia Gravis Composite (MGC) (MD = − 2.97 [− 4.27, − 1.67], P < 0.00001), 15-item revised version of the Myasthenia Gravis Quality of Life (MGQoL15r) (MD = − 2.52 [− 3.54, − 1.50], P < 0.00001), without increasing the risk of safety. The subgroup analysis showed that efgartigimod was more effective than placebo in MG-ADL responders. Rozanolixizumab was more effective than the placebo except in QMG, and batoclimab was more effective than the placebo except in MG-ADL responder. Nipocalizumab did not show satisfactory efficacy in all outcomes. With the exception of rozanolixizumab, all drugs showed non-inferior safety profiles to placebo.

FcRn inhibitors have good efficacy and safety in patients with MG. Among them, efgartigimod and nipocalimab were effective without causing an increased safety risk. Rozanolixizumab, despite its superior efficacy, caused an increased incidence of adverse events. Current evidence does not suggest that nipocalimab is effective in patients with MG.