Added IVIG is Effective in Myositis Save

IVIG (Octagam 10%) was FDA approved by the FDA for the treatment of adult dermatomyositis in July 2021.  

This double-blind, randomized, placebo-controlled clinical trial included 44 adult patients with newly diagnosed IIMs (no prior immunosuppressives). All were treated with high dose prednisone and then randomized 1:1 to receive add-on IVIG (2.0 g/kg body weight) or placebo at 0, 4, and 8 weeks. The primary outcome was the Total Improvement Score (TIS) at 12 weeks: a weighted composite score reflecting myositis change.

IIM subtypes included: IMNM (n = 16; 3-hydroxy-3-methylglutaryl-coenzyme A reductase [HMGCR], n = 11; signal recognition particle [SRP], n = 3; seronegative, n = 2) and DM (n = 13; transcription intermediary factor 1 γ [TIF1γ], n = 4; Mi-2, n = 4; small ubiquitin-like modifier activating enzyme 1 [SAE1], n = 2; nuclear matrix protein 2 [NXP2], n = 1; seronegative, n = 2).

A total of 42 patients (mean 59 yrs; 50% female) reached a primary end point. The mean TIS at 12 weeks was:

• IVIG: 60.0
• Placeblo: 42.5 (P = .01).
• Moderate and major improvement favored IVIG (21 & 16) over placebo (10 & 5)

The median time to moderate response was 4 weeks in the IVIG and 12 weeks in the placebo group (P = .005). 

IVIG led to a higher TIS at 12 weeks, better responses and shorter time to improvement. One asymptomatic deep venous thrombosis was found in the IVIG group.