POS0359 EFFECTIVENESS OF RITUXIMAB IN IGG4 RELATED DISEASE
Authors: F. López-Gutiérrez, J. Loricera, C. Hormigos, D. Freites, M. Rodríguez Laguna, P. Moya, M. López I Gómez, H. Corominas, Á. García-Aparicio, J. Font, I. Casafont-Solé, P. Martinez Calabuig, E. Castaneda, C. Merino Argumánez, R. Zas, R. Melero, E. Galíndez-Agirregoikoa, A. Hernández, L. Pantoja, I. Braña Abascal, V. Jovani, E. Valls-Pascual, N. Mena-Vázquez, A. Gallego, S. Fernández, R. Veroz González, M. Andrés, R. Blanco
Journal: Annals of the Rheumatic Diseases (2024)

<h3>Background:</h3> IgG4-related disease (IgG4-RD) is a systemic fibroinflammatory disease often associated with elevated serum IgG4 levels. High dose corticosteroids are the cornerstone of treatment, but relapses and side-effects are frequent, requiring synthetic and/or biologic immunosuppressants. Rituximab (RTX) seems to be effective in IgG4-RD. <h3>Objectives:</h3> To assess the effectiveness of RTX in IgG4-RD patients. <h3>Methods:</h3> Multicentre retrospective obsevational study of IgG4-RD patients treated with RTX. Outcomes were clinical and serologic response, as well as safety. <h3>Results:</h3> We included 44 patients (33 men/11 women; mean age±SD 54.6±12.8 years) with IgG4-RD, treated with RTX (Table 1). The most affected organs were lymph nodes (n=24; 54.5%), retroperitoneum (n=15; 34.1%), ear nose and throat (n=13; 29.5%), aorta (n=12; 27.3%), lung/pleura (n=12; 27.3%), kidney (n=12; 27.3%), orbit (n=12; 27.3%), pancreas (n=9; 20.4%), lacrimal glands (n=8; 18.2%), salivary glands (n=8; 18.2%), liver/biliary duct (n=7; 15.9%), pachymeninges (n=3; 6.8%) and mesenterium (n=2; 4.5%). All but 2 patients had received oral corticosteroids, and 12 patients also received corticosteroid boluses. 23 patients received conventional cDMARDs: methotrexate (MTX) (n=15), azathioprine (n=6), and mycophenolate mophetil (n=2). Main RTX schedule was of 1g x 2 (n=35), 500mg x2 (n=5) and 375 mg/m<sup>2</sup> (n=3). 30 patients received maintenance treatment with RTX. Median time from diagnosis to RTX initiation was 5 (0-72) months (Table 2). After 12 and 24 moths of follow-up, complete and partial clinical improvement was observed in 15 (50%) and 13 (43.33%) and in 16 (64%) and 7 (28%) patients, respectively. Only 5 relapses were observed. Prednisone could be discontinued in 11 patients. 3 patients died during follow up. One patient needed ICU admission because of Influenza pneumonia, and 2 developed a larynx and a breast cancer, respectively. <h3>Conclusion:</h3> RTX seems to be an effective and relatively safe therapy in IgG4-RD, with a low rate of relapse. <h3>REFERENCES:</h3> <b>NIL.</b> <h3>Acknowledgements:</h3> Cristina Arciniega (Hospital de Mérida), Maria Lourdes Mateo Soria (Hospital German Trias i Pujol), Jorge Juan Fragío Gil (Hospital General Universitario de Valencia), Roxana González Mazarío (Hospital General Universitario de Valencia), Santiago Muñoz (Hospital Universitario Infanta Sofía), Iñigo Jesús Rua Figueroa, (Hospital Universitario de Gran Canaria Dr Negrin), Noelia Cabaleiro Raña (Hospital de Montecelo), as part of the Rituximab in IgG4 Related Disease Spanish Cooperative Group. <h3>Disclosure of Interests:</h3> Fernando López-Gutiérrez Janssen, Abbvie, Roche, Novartis, MSD, UCB Pharma, Celgene, Lilly, Pfizer, Galápagos, Javier Loricera Roche, Galápagos, Novartis, UCB Pharma, MSD, Celgene, Astra Zeneca, and Grünenthal, Janssen, Abbvie, Roche, Novartis, MSD, UCB Pharma, Celgene, Lilly, Pfizer, Galápagos, Cristina Hormigos: None declared, Dalifer Freites: None declared, María Rodríguez laguna: None declared, Patricia Moya: None declared, Marta López I Gómez: None declared, Hèctor Corominas: None declared, Ángel García-Aparicio: None declared, Judit Font: None declared, Ivette Casafont-Solé: None declared, Pablo Martinez Calabuig: None declared, Elisabet Castaneda: None declared, Carolina Merino Argumánez: None declared, Raquel Zas: None declared, Rafael Melero: None declared, Eva Galíndez-Agirregoikoa Abbvie, Pfizer, Lilly, Novartis, UCB, Amgen, Janssen, Andrea Hernández: None declared, Lucía Pantoja: None declared, Ignacio Braña Abascal: None declared, Vega Jovani: None declared, Elia Valls-Pascual: None declared, Natalia Mena-Vázquez: None declared, Adela Gallego: None declared, Sabela Fernández: None declared, Raúl Veroz González: None declared, Mariano Andrés: None declared, Ricardo Blanco AbbVie, Pfizer, Roche, Bristol-Myers, Lilly, Galapagos, Novartis, Janssen, GSK, UCB, and MSD, AbbVie, Pfizer, Roche, Lilly, Janssen.