ABS0224 RITUXIMAB IN REAL LIFE: 3-YEAR DATA FROM THE BIOTHERAPY REGISTRY OF THE MOROCCAN SOCIETY OF RHEUMATOLOGY (RBSMR): A MULTICENTER STUDY

Abstract

<h2>Abstract</h2><h3>Background:</h3> Rituximab (RTX) is typically used as a second-line treatment according to European and international guidelines. In Morocco, it has been used as a first-line therapy due to its better tolerance with respect to tuberculosis, its affordability, and ease of sequential use. <h3>Objectives:</h3> To evaluate the effectiveness and safety of RTX in clinical practice for rheumatoid arthritis (RA) based on data from the Moroccan Society of Rheumatology's biotherapy registry (RBSMR). <h3>Methods:</h3> The registry includes 224 patients with RA. We identified the number of patients on RTX, specifying those for whom RTX was prescribed as a first-line treatment, and those who received RTX as a second-line treatment, along with the number of retreatments. We describe the clinical phenotype, biological, and radiological characteristics. Finally, we assess the effectiveness (percentage of remission and low disease activity (LDA)) and safety (incidence of hypersensitivity reactions and infections) of Rituximab. <h3>Results:</h3> A total of 170 patients (76.2%) received Rituximab; 164 patients used RTX as a first-line treatment, while only 6 received it as a second-line treatment. Forty-two patients underwent retreatment, with a mean retreatment interval of 14 months. The average patient age was 51.9 ± 11.1 years, with a female predominance of 88.2%. The average RA duration was 11.6 years [6.8–17.1], and RA was seropositive in 87.1% of patients. Radiologically, RA was erosive in 67.8% of patients, with carpal involvement in 56.2%. The percentage of patients on corticosteroids was 77.1%. Regarding csDMARDs, 47.3% of patients were on Methotrexate, 28.5% on Sulfasalazine, 12.7% on Leflunomide, and 8.5% on Hydroxychloroquine. For the study of RTX effectiveness, the mean DAS28 score at baseline was 5.65 ± 1.06. The percentage of remission or LDA was 45.2% at 12 months, and 41.9% at 36 months. According to the EULAR response criteria for RA, at 12 months, 73.9% (82/111) had a good response, 15.30% (17/111) had a moderate response, and 10.80% (12/111) were experiencing therapeutic escape. At 36 months, 74% (54/73) had a good response, 16.4% (12/73) had a moderate response, and 9.60% (7/73) were experiencing treatment failure. Regarding the pre-biotherapy assessment, there were 8 cases of latent tuberculosis, all treated. For the study of RTX safety, the incidence of adverse effects due to RTX over 36 months was 14.3/100 patient-years, with serious adverse events at 4.1/ 100 patient-years distributed as follows: infusion reactions (6/21); immediate intolerances (4/21); tumors, Grade 1 urothelial neoplasia, Grade 2 Invasive breast carcinoma (2/21); shock (2/21); delayed intolerances (2/21), induced lupus (1/21) facial paralysis (1/21), acute swollen leg (1/21). The infection rate is 8.2 per 100 patient-years; the most frequent types are: community-acquired respiratory infections (2.35/ 100 patient-years) followed by urinary tract infection (1.56/ 100 patient-years), and ENT (ear, nose, and throat) infections (1.37/ 100 patient-years). There were no cases of tuberculosis infection under RTX. <h3>Conclusion:</h3> Our registry demonstrates the effectiveness of using RTX as a first-line therapy, with good response rates within the first year, and favorable safety outcomes, particularly in the context of endemic tuberculosis in the country. For medico-economic reasons, we advocate for pragmatic treatment only during rheumatoid arthritis flares. Finally, sequential infusions accommodate patients who are distant from healthcare facilities. <h3>REFERENCES:</h3> <b>NIL</b>. <h3>Acknowledgements:</h3> <b>NIL</b>. <h3>Disclosure of Interests:</h3> <b>None declared</b>. © The Authors 2025. This abstract is an open access article published in Annals of Rheumatic Diseases under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Neither EULAR nor the publisher make any representation as to the accuracy of the content. The authors are solely responsible for the content in their abstract including accuracy of the facts, statements, results, conclusion, citing resources etc.