IV immunoglobulin may not help reduce corticosteroid dose among patients with myasthenia gravis

In a new study conducted by Vera Brill, it was shown that the daily corticosteroids (CS) dose could not be decreased by caprylate/chromatography purified (IGIV-C) any more than a placebo could. These findings imply that the effects of IGIV-C and CS are not synergistic and may even involve distinct mechanisms. The findings of this study were published in Neurology Journal.

Neuromuscular junction dysfunction is a hallmark of the autoimmune illness myasthenia gravis (MG). In many cases, corticosteroids and intravenous immunoglobulin (IVIG) are used as treatments. This study looked at whether immune globulin (human), 10% caprylate/chromatography purified could help CS-dependent MG patients reduce their dose.

Patients with CS-dependent MG (MGFA class II-Iva; AChR+) received a loading dose of 2 g/kg IGIV-C over two days (maximum 80 g/day) or placebo at week 0 of this randomized, double-blind, placebo-controlled experiment (baseline). Through week 36, maintenance doses (1 g/kg IGIV-C or placebo) were given every three weeks. CS was reduced starting at week 9 and continued until week 36, barring a patient worsening. In patients who got worse, CS dosages were raised. If deterioration did not improve after six weeks or a second CS increase was necessary, patients were removed from the study. A 50% reduction in CS dose served as the primary effectiveness objective (at week 39). The study and follow-up involved evaluating secondary and safety endpoints (weeks 42 and 45).

The key findings of this study were:

1. The IGIV-C treatment (60.0% of patients) and placebo (63.3%) did not significantly differ in the primary goal ( 50% reduction in CS dose).

2. For secondary endpoints, there were no noteworthy variations. According to safety data, IGIV-C was well tolerated.

In conclusion, this trial shows Class II evidence that IVIG infusions do not increase the proportion of patients who achieve a 50% reduction in corticosteroid dose in comparison to placebo in adult patients with MG.

Reference:

Bril, V., Szczudlik, A., Vaitkus, A., Rozsa, C., Kostera-Pruszczyk, A., Hon, P., Bednarik, J., Tyblova, M., Köhler, W., Toomsoo, T., Nowak, R. J., Mozaffar, T., Freimer, M. L., Dimachkie, M. M., Distad, B. J., … Mondou, E. (2022). A randomized, double-blind, placebo-controlled trial of the corticosteroid-sparing effects of immunoglobulin in myasthenia gravis. Neurology, 10.1212/WNL.0000000000201501. https://doi.org/10.1212/WNL.0000000000201501