ANIFROLUMAB IN SYSTEMIC LUPUS ERYTHEMATOSUS. SPANISH NATIONAL REGISTRY IN A REAL-WORLD SETTING

Background: Anifrolumab (ANI) is a human monoclonal antibody that binds to the type I interferon receptor subunit 1 (IFNAR1), thus blocking the biological activity of type I IFNs. ANI was approved by Spanish authorities on June 1, 2023. Its use is indicated in adults with moderately to severely active autoantibody-positive systemic lupus erythematosus (SLE) in combination with standard treatment. Objectives: To describe in Spanish clinical practice since its approval a) SLE profile of patients, b) effectiveness and c) safety. Methods: Descriptive, retrospective, multicenter study in patients diagnosed with SLE according to EULAR/ACR 2019, SLICC and/or ACR 1997 diagnostic criteria. Data regarding were collected from medical records (June 2023-January 2024). Demographic features, clinical and laboratory variables, previous and concomitant therapy, activity index (SLE-DAS, SLEDAI-2k, PGA), organic damage index (SLICC SDI) and safety were assessed. Results: Baseline characteristics of patients and therapy before ANI are summarized in Table 1 . A total of 91 patients (82 women/9 men), mean age 32.7±11.5 years (range 15-59 years) (38 hospitals) were included. The main reason for starting ANI was: skin activity (n=60, 65.9%), joint activity (n=52, 57.1%), hematological activity (n=25, 27.5%), renal activity (n=2, 2.2%), corticosteroids dependence (n=5, 5.5%) and serious side effects with belimumab (BLM) (n=2, 2.2%). All patients received 300 mg/4 w of ANI except one patient who received a loading dose (900 mg/4 w x3 months and after 300 mg/4 w) due to renal involvement. Concomitant treatments with ANI were: corticosteroids (n=78), antimalarials (n=68), mycophenolate mofetil (MMF) (n=23), methotrexate (MTX) (n=13), azathioprine (AZA) (n=5), tacrolimus (n=5), leflunomide (LFN) (n=2), rituximab (RTX) (n=1), cyclophosphamide (CYM) (n=1), sulfones (n=2) and anakinra (n=1). A rapid and maintained significant decreases in SLE-DAS, SLEDAI-2k, PGA and anti-dsDNA antibodies were observed from 1 month until the last visit. Complement C3 and C4 levels also increased significantly ( Figure 1 ). No increase in the chronicity index was observed. After a follow-up of 4.8±3.6 months the main side effects observed were: herpes zoster (n=3), arterial hypotension (n=2), headache (n=2), suppurative hidradenitis (n=1), influenza A pneumonia (n=1), skin reaction (n=1), herpes simplex virus infection and urinary infection (n=1). In follow-up, 7 patients discontinued treatment due to primary failure (n=3), secondary failure (n=2), severe pneumonia (n=1), arterial hypotension (n=1). Conclusion: In our cohort of SLE patients in a real-world setting, ANI has showed a rapid effectiveness, and a relatively good safety. Therefore, ANI seems to be a good choice to treat patients refractory to other therapies. ANI in severe and refractory patients even was used combined with other biologic therapy. REFERENCES: [1] Aringer M, Costenbader K, Daikh D, et al. 2019 European League Against Rheumatism/American College of Rheumatology classification criteria for systemic lupus erythematosus. Ann Rheum Dis. 2019 Sep;78(9):1151-1159. Table 1. Clinical manifestations and treatments received before starting anifrolumab Clinical manifestations before ANI N (%) Therapy before ANI N (%) Concomitant therapy with ANI N (%) articular 87 (95.6%) oral steroids 88 (96.7%) oral steroids 78 (85.7%) cutaneous 75 (82.4%) antimalarials 88 (96.7%) antimalarials 68 (74.7%) hematological 57 (62.6%) BLM 73 (80.2%) MMF 23 (25.3%) oral ulcers 47 (51.6%) MMF 46 (50.5%) MTX 13 (14.3%) alopecia 46 (50.5%) AZA 38 (41.7%) AZA 5 (5.5%) renal 30 (33%) RTX 34 (37.3%) tacrolimus 5 (5.5%) serositis 28 (30.8%) MP boluses 32 (35.1%) leflunomide 2 (2.2%) neuropsychiatric 12 (13.2%) CYM 19 (20.9%) sulfones 2 (2.2%) digestive 6 (6.6%) tacrolimus 9 (9.9%) RTX 1 (1.1%) Abbreviations in alphabetical order: ANI: anifrolumab; AZA: azathioprine; BLM: belimumab; CYM: cyclophosphamide; MMF: mycophenolate mofetil; MP: methylprednisolone; MTX: Methotrexate; RTX: rituximab CYM 1 (1.1%) anakinra 1 (1.1%) Figure 1. Evolution of C3, C4 and anti-dsDNA levels and activity and organ damage indices after starting anifrolumab. Acknowledgements: NIL. Disclosure of Interests: Vanesa Calvo-Río Abbie, Lilly, Grünenthal, AMGEN, MSD, Novartis, Galápagos, Vifor, GSK, Otsuka, Janssen, M. Retuerto-Guerrero: None declared, Judit Font: None declared, Ivette Casafont-Solé: None declared, A. Mayo-Juanatey: None declared, Juan Jose Alegre Sancho: None declared, Dalifer Freites: None declared, Cristina Hormigos: None declared, Noemí Garrido-Puñal: None declared, Guillermo Gonzalez Arribas: None declared, Juan Roberto Miguelez Sanchez: None declared, Andrea García-Valle: None declared, Marta Ibañez: None declared, Fernando Lozano Morillo: None declared, Ángel García Manzanares: None declared, S. Sandoval-Moreno: None declared, Josefina Cortés-Hernández: None declared, Deseada Palma Sanchez: None declared, Leticia Lojo: None declared, Evelin Cecilia Cervantes Pérez: None declared, Paz Collado: None declared, Cristina Arciniega Larios: None declared, Luis Sala Icardo: None declared, Eztizen Labrador-Sánchez: None declared, Cilia Peralta-Ginés: None declared, Nahia Plaza-Aulestia: None declared, Miguel Medina Malone: None declared, Jose Rosas Gómez de Salazar: None declared, Montserrat Corteguera: None declared, Laura Cebrián-Méndez: None declared, Fred Antonio Anton Pages: None declared, Jose Ramón Lamúa Riazuelo: None declared, Maria Dolores Fábregas Canales: None declared, María José Alados Hernández: None declared, Marta Garijo Bufort: None declared, Anna Pàmies: None declared, Luis Sarabia De Ardanaz: None declared, Rodrigo Aguirre-del-Pino: None declared, Jose Angel Cabezas Lefler: None declared, Alvaro Seijas-Lopez: None declared, Maria del Carmen Carrasco Cubero: None declared, Ana Lopez-Ceron Cofiño: None declared, Vera Ortiz-Santamaria: None declared, Santos Castañeda: None declared, Carmen Bejerano: None declared, Ricardo Blanco Abbvie, Pfizer, Roche, Bristol-Myers-Squibb, Janssen, Lilly, Novartis, UCB, and MSD, Abbvie, MSD, Roche. DOI: 10.1136/annrheumdis-2024-eular.2481 Keywords: Observational studies/ registry, Biological DMARD Citation: , volume 83, supplement 1, year 2024, page 1816Session: Systemic lupus erythematosus (Publication Only)

Observational studies/ registry, Biological DMARD