IVIG Shows Promising Results as Therapy for Inflammatory Myopathies

Patients diagnosed with idiopathic inflammatory myopathies (IIMs), such as dermatomyositis, exhibited greater improvement when treated with intravenous immunoglobulin (IVIG) in conjunction with prednisone compared to those who received only the steroid in a placebo-controlled randomized trial.

Study Findings

The Total Improvement Score (TIS), derived from six measures of IIM disease activity, rose by an average of 60 points among the 23 patients receiving IVIG and prednisone over 12 weeks, whereas a 42.5-point increase was noted for the 19 patients administered prednisone alone, considered the standard treatment. This data comes from the research led by Joost Raaphorst, MD, PhD, from Amsterdam University Medical Center in the Netherlands.

Additional efficacy endpoints also favored IVIG. However, concerns about thromboembolic risks associated with IVIG arose due to incidents of deep vein thrombosis (DVT) and a patient’s death from unknown causes, as reported in JAMA Neurology.

Raaphorst and colleagues suggest that IVIG should be regarded as an adjunct to prednisone for initial treatment in IIMs, alongside the potential use of prophylactic anticoagulant therapies.

Understanding IIMs

IIMs comprise a group of neuromuscular disorders stemming from an autoimmune response, primarily affecting skeletal muscle, though other organs such as skin, lungs, heart, and joints can also be involved. Notably, IIMs impact men and women equally, unlike many other autoimmune diseases. Current treatment typically involves corticosteroids, especially prednisone. Cases that do not respond adequately are being explored for other innovative therapies like chimeric antigen receptor (CAR) T-cell therapy, though the associated costs and risks make them unsuitable for newly diagnosed patients.

Trial Design and Protocol

In this study, initiated in 2021, a total of 44 patients were recruited; however, two opted out early. The average age of participants was 59, with a balanced gender distribution. Patients had an average duration of symptoms of nearly six months prior to diagnosis. Alongside muscle pain and weakness, other symptoms affected various tissues, most frequently the skin, heart, and lungs.

Prednisone was initiated at 1 mg/kg with a cap of 80 mg daily, tapering down by 10 mg each month. IVIG was administered at a dosage of 2 g/kg at weeks 0, 4, and 8, while the placebo was saline. Blinding was maintained for participants and most staff, apart from nurses involved in the IVIG administration.

TIS served as the study’s primary endpoint, measured through various instruments ranging from muscle tests to serum enzyme levels. By week 4, patients receiving IVIG had improved substantially compared to the placebo group (39 points versus 30 points). At week 12, the mean difference extended to 17.5 points (P=0.01).

Secondary outcomes indicated notable improvements: at week 12, 91% of the IVIG group experienced moderate improvement compared to 53% in the placebo group, while 70% of IVIG patients exhibited major improvement versus just 26% in the placebo group.

Adverse Events and Considerations

There were 148 adverse events reported in the IVIG group compared to 104 in the placebo group, with most classified as non-serious. Serious infections occurred in both groups, and two IVIG patients presented with myocarditis. An incident of DVT was also observed in one IVIG patient without symptoms.

Tragically, one participant from the IVIG group passed suddenly; they had previously withdrawn due to clinical deterioration but subsequently received an additional dose. The sudden nature of this death drew attention to the potential thromboembolic risks associated with IVIG.

The researchers underline the importance of monitoring IIM patients treated with IVIG for thromboembolic events and suggest considering preventive measures. They also noted limitations in their study, including a small patient population and the trial’s specific geographic context, which may affect broader applicability.

Disclaimer: This article is for informational purposes only and should not be used as a substitute for professional medical advice or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.

Fuente: https://www.medpagetoday.com/rheumatology/generalrheumatology/122989