HEALTHCARE RESOURCE UTILIZATION AND COSTS IN JAPANESE PATIENTS WITH GENERALIZED MYASTHENIA GRAVIS INITIATING EFGARTIGIMOD: A REAL-WORLD RETROSPECTIVE ANALYSIS
Author(s)
CECILE BLEIN, PhD1, Koichi Tsuda, MSc, MBA2, Ryohei Aoyagi, PhD2, Yunlong Zheng, PhD3, Jiangyuan Luo, BSc4, Sho Inagaki, MSc3, Masanori Takahashi, Professor5, Hirofumi Teranishi, PhD2;
1argenx, Zwijnaarde, Belgium, 2argenx, Minato-ku, Japan, 3ZS Associates, Osaka, Japan, 4ZS Associates, Minato-ku, Japan, 5Osaka University, Suita, Japan
1argenx, Zwijnaarde, Belgium, 2argenx, Minato-ku, Japan, 3ZS Associates, Osaka, Japan, 4ZS Associates, Minato-ku, Japan, 5Osaka University, Suita, Japan
OBJECTIVES: Generalized myasthenia gravis (gMG) is a rare, chronic, autoimmune disorder associated with substantial disease burden particularly from hospitalizations due to myasthenia crisis and other exacerbations. While evidence from the United States suggests that efgartigimod (EFG) reduces in-patient events, real-world data from Japan remain scarce. This study aimed to evaluate the impact of intravenous/subcutaneous EFG initiation on healthcare resource utilization (HRU) and associated costs among adult patients with gMG in Japan.
METHODS: We conducted a retrospective cohort analysis using hospital-based claims from Medical Data Vision. Patients aged ≥15 years who initiated EFG between May 1, 2022, and April 30, 2025, and had ≥1 gMG diagnosis and ≥1 healthcare encounter during the 12 months pre-EFG initiation (baseline) and ≥3 months post-EFG initiation (follow-up) were included. The index date was the first EFG administration. HRU outcomes, including hospital admissions, length of stay (LoS), ICU admissions, and related costs were compared between baseline and follow-up periods.
RESULTS: Among 539 eligible patients (62% female; mean age 56.3 years; mean Charlson comorbidity index 3.5), most had prior oral glucocorticoid exposure (94%), while prior biologic use was limited (7%). Median follow-up was 443 days. Following EFG initiation, hospital admissions per patient per year (PPPY) decreased 37% (1.34 to 0.85, baseline to follow-up). Mean LoS per hospitalization remained similar (12.8 to 12.4 days), while total LoS PPPY decreased 28% (17.85 to 12.92 days) for hospitalizations with both admission/discharge dates within the baseline/follow-up window, respectively. ICU admissions decreased 53% (5.1% to 2.4%), and hospitalization costs decreased 15% (1.82 to 1.54 million JPY, or 11,622 to 9,882 USD, 1 USD = 156.18 JPY).
CONCLUSIONS: Initiation of EFG in Japanese adults with gMG was associated with meaningful reductions in hospital admissions, total LoS, ICU admissions, and inpatient costs, supporting its real-world effectiveness in this population.
METHODS: We conducted a retrospective cohort analysis using hospital-based claims from Medical Data Vision. Patients aged ≥15 years who initiated EFG between May 1, 2022, and April 30, 2025, and had ≥1 gMG diagnosis and ≥1 healthcare encounter during the 12 months pre-EFG initiation (baseline) and ≥3 months post-EFG initiation (follow-up) were included. The index date was the first EFG administration. HRU outcomes, including hospital admissions, length of stay (LoS), ICU admissions, and related costs were compared between baseline and follow-up periods.
RESULTS: Among 539 eligible patients (62% female; mean age 56.3 years; mean Charlson comorbidity index 3.5), most had prior oral glucocorticoid exposure (94%), while prior biologic use was limited (7%). Median follow-up was 443 days. Following EFG initiation, hospital admissions per patient per year (PPPY) decreased 37% (1.34 to 0.85, baseline to follow-up). Mean LoS per hospitalization remained similar (12.8 to 12.4 days), while total LoS PPPY decreased 28% (17.85 to 12.92 days) for hospitalizations with both admission/discharge dates within the baseline/follow-up window, respectively. ICU admissions decreased 53% (5.1% to 2.4%), and hospitalization costs decreased 15% (1.82 to 1.54 million JPY, or 11,622 to 9,882 USD, 1 USD = 156.18 JPY).
CONCLUSIONS: Initiation of EFG in Japanese adults with gMG was associated with meaningful reductions in hospital admissions, total LoS, ICU admissions, and inpatient costs, supporting its real-world effectiveness in this population.
Conference/Value in Health Info
2026-05, ISPOR 2026, Philadelphia, PA, USA
Value in Health, Volume 29, Issue S6
Code
EE244
Topic
Economic Evaluation
Topic Subcategory
Cost/Cost of Illness/Resource Use Studies
Disease
SDC: Neurological Disorders, SDC: Rare & Orphan Diseases