Background/Purpose: Idiopathic inflammatory myopathies (IIM) are autoimmune diseases typically characterized by muscle weakness. Intravenous Immunoglobulin (IVIg) is an effective immunomodulatory therapy in patients with refractory IIM. However, data is limited regarding trajectory of patient reported symptom response and tolerability of IVIg among patients with IIM. This study aims to report the symptom change and treatment tolerance of IVIg naïve adults with IIM through implementation of a structured outcomes monitoring program within a home infusion and specialty pharmacy model.

Methods: As part of a proprietary clinical outcomes program, an IIM clinical care and patient-reported outcomes monitoring program was developed by a multidisciplinary team within a home infusion and specialty pharmacy organization. The patients with confirmed IIM diagnosis who were IVIg treatment naïve and had ≥2 IVIg infusions, were recruited between 5/2024 – 3/2025. The program integrated clinical safety assessments and structured collection of patient symptoms via Health Assessment Questionnaire (HAQ), Patient Global Disease Activity (PTGD), and Patient-Reported Outcomes Measurement Information System (PROMIS®) Physical Function (v2, 8b), Fatigue (v1, 7a), and Pain Interference (v1.1; 6a) and Brief Pain Inventory (BPI). Patients also responded to anchor questions regarding their symptoms. All data was collected by specialty pharmacy nurses prior to each IVIg infusion. Adverse drug reactions (ADRs) were identified through pharmacist-led patient interviews and review of nursing infusion documentation. Descriptive statistical analyses were conducted to summarize key findings.

Results: A total of 21 patients with IIM were enrolled in the program, of whom 14 (7 DM, 2 IMNM, and 5 PM; median age of 63 [47-49]) met the inclusion criteria and received their monthly IVIg infusions through a national home infusion service (Table 1). Seventy-five infusion-related assessments were collected, with a mean 5 monthly IVIg infusions per patient (range 2-9). Baseline organ involvement of patients included muscle in 100% (n=14), joint in 57% (n=8), skin in 57% (n=8), and lung in 43% (n=6). One month after the 1st infusion, 6 patients (42.9%) reported improvement in their physical function and fatigue, 7 (50%) reported staying the same, and 1 reported worsening (7%) (Figure 1). Most patients continued to report improvement at each infusion after 2nd, 3rd, and 4th infusions. Similar trends were observed for PTGD, pain intensity and interference. No severe ADRs were reported during the first 9 infusions. The most common side effect was headache (28.6%) and other mild side effects were within reported incidence rates (Table 2).

Conclusion: This study demonstrated that IVIg-naïve IIM patients can be effectively monitored through a nurse-led, structured outcomes program which could represent a scalable approach for managing complex immunotherapy in decentralized environments. Approximately half of the patients reported improvement after one IVIg infusion. Symptomatic improvement and lack of serious adverse events suggest that the IVIg is well tolerated and may offer meaningful benefits to patients with IIM.

Table 1 – Baseline characteristics of the patients with IIM who receive IVIg through home infusion.

Table 2. Adverse reactions during IVIg infusions.

Figure 1. Change in patient reported outcome measures of patients with IIM at each IVIg infusion.

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ACR Meeting Abstracts - https://acrabstracts.org/abstract/real-world-observations-on-symptom-response-and-tolerability-of-intravenous-immunoglobulin-in-patients-with-inflammatory-myopathies-through-a-nurse-led-outcomes-monitoring-program-in-a-home-infusion-s/