Document Type
Article
Publication Date
2-2025
Identifier
DOI: 10.1002/art.42985; PMCID: PMC11782109
Abstract
OBJECTIVE: Rheumatologic disease-associated hemophagocytic lymphohistiocytosis (HLH), a rare, life-threatening, systemic hyperinflammatory syndrome, occurs as a complication of underlying rheumatologic disease. Real-world evidence is lacking on emapalumab, a fully human monoclonal antibody that neutralizes the proinflammatory cytokine interferon-γ, approved for treating patients with primary HLH.
METHODS: REAL-HLH, a retrospective medical chart review study conducted across 33 US hospitals, assessed real-world treatment patterns and outcomes in patients with HLH treated with one or more dose of emapalumab between November 20, 2018, and October 31, 2021. Data are presented for the subset of patients with rheumatologic disease-associated HLH.
RESULTS: Fifteen of 105 patients (14.3%) had rheumatologic disease-associated HLH. Of these, nine (60.0%) had systemic juvenile idiopathic arthritis, and one (6.7%) had adult-onset Still disease. Median (range) age at HLH diagnosis was 5 (0.9-39) years. Most patients (9 of 15; 60.0%) initiated emapalumab in an intensive care unit. Emapalumab was most frequently initiated for treating refractory or recurrent (10 of 15; 66.7%) disease. Most patients received HLH-related therapies before (10 of 15; 66.7%) and concurrently with (15 of 15; 100.0%) emapalumab. Emapalumab-containing regimens stabilized or achieved physician-determined normalization of most laboratory parameters, including absolute neutrophil count and absolute lymphocyte count (13 of 14; 92.9%), chemokine ligand 9 (9 of 11; 81.8%), and platelets and alanine transaminase (11 of 14; 78.6%), and reduced glucocorticoid dose by 80%. Overall survival and 12-month survival probability from emapalumab initiation were 86.7%.
CONCLUSION: Emapalumab-containing regimens stabilized or normalized most key laboratory parameters, reduced glucocorticoid dose, and were associated with low disease-related mortality, thereby demonstrating potential benefits in patients with rheumatologic disease-associated HLH.
Journal Title
Arthritis Rheumatol
Volume
77
Issue
2
First Page
226
Last Page
238
MeSH Keywords
Humans; Lymphohistiocytosis, Hemophagocytic; Retrospective Studies; Male; Female; United States; Child; Adolescent; Child, Preschool; Antibodies, Monoclonal; Adult; Infant; Treatment Outcome; Rheumatic Diseases; Young Adult; Antibodies, Monoclonal, Humanized; Antibodies, Neutralizing
PubMed ID
39245963
Keywords
Humans; Lymphohistiocytosis, Hemophagocytic; Retrospective Studies; Male; Female; United States; Child; Adolescent; Child, Preschool; Antibodies, Monoclonal; Adult; Infant; Treatment Outcome; Rheumatic Diseases; Young Adult; Antibodies, Monoclonal, Humanized; Antibodies, Neutralizing
Recommended Citation
Chandrakasan S, Allen CE, Bhatla D, et al. Emapalumab Treatment in Patients With Rheumatologic Disease-Associated Hemophagocytic Lymphohistiocytosis in the United States: A Retrospective Medical Chart Review Study. Arthritis Rheumatol. 2025;77(2):226-238. doi:10.1002/art.42985
Comments
Grants and funding
This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.
Publisher's Link: https://acrjournals.onlinelibrary.wiley.com/doi/10.1002/art.42985