IVIG Plus Prednisone Improves Early Myositis Response

Intravenous immunoglobulin (IVIG) added to high-dose prednisone produced greater and faster improvement in adults with newly diagnosed idiopathic inflammatory myopathies (IIMs) than prednisone plus placebo, according to a randomized clinical trial published in JAMA Neurology. The primary assessment occurred at 12 weeks.

The double-blind, placebo-controlled study was conducted at a tertiary referral center between September 2021 and September 2025. Investigators assessed 94 adults for inclusion; 50 were excluded or declined participation. The 44 enrolled participants had no or limited prior immunosuppressive treatment. They were randomly assigned 1:1 to IVIG 2.0g/kg or placebo at weeks 0, 4, and 8. All initiated prednisone 1mg/kg/day, capped at 80mg/day.

The primary endpoint was the Total Improvement Score (TIS), a weighted composite of six measures reflecting changes in myositis activity. Among 42 participants who reached the primary endpoint, 23 received IVIG and 19 received placebo; mean age was 58.7 years, and half were female. At week 12, mean TIS was 60.0 with IVIG versus 42.5 with placebo (P = .01).

Moderate improvement, defined as TIS ≥40, occurred in 21 IVIG recipients (91%) versus 10 placebo recipients (53%). Major improvement, defined as TIS ≥60, occurred in 16 (70%) versus 5 (26%), respectively. The major improvement analysis was conducted post hoc. Median time to moderate improvement was 4 weeks with IVIG versus 12 weeks with placebo (P = .005).

One asymptomatic deep venous thrombosis was detected in the IVIG group. Investigators concluded that IVIG added to high-dose prednisone improved the extent and speed of clinical response in adults with newly diagnosed IIMs.

Source: Özkaynar P, Evers S, Kamperman R, et al. Intravenous immunoglobulin add-on in newly diagnosed idiopathic inflammatory myopathies: a randomized clinical trial. JAMA Neurol. Published online September 14, 2026. doi:10.1001/jamaneurol.2026.3088