Burden of Intravenous Immunoglobulin Use Among Adults With Generalized Myasthenia Gravis in Japan
Author(s)
Hirofumi Teranishi, PhD1, Koichi Tsuda, MBA1, Daisuke Harada, PhD1, Challa Yachendra, BTech2, Anthony Nguyen, PhD3, Mai Sato, PhD4, Cecile Blein, PhD5.
1argenx Japan, Tokyo, Japan, 2ZS Associates, Karnataka, India, 3ZS Associates, Durham, NC, USA, 4ZS Associates, New York, NY, USA, 5argenx BVBA, Ghent, Belgium.
1argenx Japan, Tokyo, Japan, 2ZS Associates, Karnataka, India, 3ZS Associates, Durham, NC, USA, 4ZS Associates, New York, NY, USA, 5argenx BVBA, Ghent, Belgium.
OBJECTIVES: To evaluate healthcare resource utilization (HRU) and costs among adults with generalized myasthenia gravis (gMG) in Japan receiving intravenous immunoglobulin (IVIg).
METHODS: A retrospective cohort study was conducted using the Japan Medical Data Vision (MDV) claims dataset (2008-2022). Adults with ≥2 gMG diagnoses (excluding ocular MG) in 2018-2021 were included. The index date was assigned at the first gMG diagnosis in 2018-2021. Patients with ≥1 claim for IVIg within one year post index were considered as IVIg users. Patients with ≥3 IVIg courses (clusters of IVIg claims ≤5 days apart) in year 1 post-index were considered frequent IVIg users, while others were intermittent IVIg users. All-cause and gMG-related HRU (inpatient [IP] and outpatient [OP]) and costs (IP, OP, and drug-related [DR] in JPY) were assessed 1 year post-index on a per-patient per-year (PPPY) basis.
RESULTS: Among 9687 gMG patients (mean age: 65 years; 56% female), 715 (7%) used IVIg (mean age: 64; 59% female), of whom 23% were frequent IVIg users (n=167; mean age: 57; 62% female), and 77% (n=548; mean age: 64; 59% female;) were intermittent IVIg users. In the 1 year after index, the all-cause total HRU rate PPPY was 12.92 (0.55 IP; 12.37 OP) and total cost PPPY was ¥3,398,148 (¥538,719 IP; ¥437,080 OP; ¥2,402,349 DR). All-cause total cost PPPY was ¥54,319,845 (¥2,141,206 IP; ¥682,549 OP; ¥51,496,090 DR) for frequent IVIg users and ¥24,262,152 (¥951,807 IP; ¥463,942 OP; ¥22,846,403 DR) for intermittent IVIg users, approximately 16x and 7x of overall gMG population, respectively. Most total utilization (94.0%) and costs (99.9%) were gMG-related.
CONCLUSIONS: In Japan, adults with gMG faced substantial economic burden, particularly frequent IVIg users. Alternative treatments may alleviate long-term economic burden.
METHODS: A retrospective cohort study was conducted using the Japan Medical Data Vision (MDV) claims dataset (2008-2022). Adults with ≥2 gMG diagnoses (excluding ocular MG) in 2018-2021 were included. The index date was assigned at the first gMG diagnosis in 2018-2021. Patients with ≥1 claim for IVIg within one year post index were considered as IVIg users. Patients with ≥3 IVIg courses (clusters of IVIg claims ≤5 days apart) in year 1 post-index were considered frequent IVIg users, while others were intermittent IVIg users. All-cause and gMG-related HRU (inpatient [IP] and outpatient [OP]) and costs (IP, OP, and drug-related [DR] in JPY) were assessed 1 year post-index on a per-patient per-year (PPPY) basis.
RESULTS: Among 9687 gMG patients (mean age: 65 years; 56% female), 715 (7%) used IVIg (mean age: 64; 59% female), of whom 23% were frequent IVIg users (n=167; mean age: 57; 62% female), and 77% (n=548; mean age: 64; 59% female;) were intermittent IVIg users. In the 1 year after index, the all-cause total HRU rate PPPY was 12.92 (0.55 IP; 12.37 OP) and total cost PPPY was ¥3,398,148 (¥538,719 IP; ¥437,080 OP; ¥2,402,349 DR). All-cause total cost PPPY was ¥54,319,845 (¥2,141,206 IP; ¥682,549 OP; ¥51,496,090 DR) for frequent IVIg users and ¥24,262,152 (¥951,807 IP; ¥463,942 OP; ¥22,846,403 DR) for intermittent IVIg users, approximately 16x and 7x of overall gMG population, respectively. Most total utilization (94.0%) and costs (99.9%) were gMG-related.
CONCLUSIONS: In Japan, adults with gMG faced substantial economic burden, particularly frequent IVIg users. Alternative treatments may alleviate long-term economic burden.
Conference/Value in Health Info
2025-09, ISPOR Real-World Evidence Summit 2025, Tokyo, Japan
Value in Health Regional, Volume 49S (September 2025)
Code
RWD78
Topic Subcategory
Health & Insurance Records Systems
Disease
SDC: Neurological Disorders