PO:08:119 | Infusional Advantage: Rituximab’s Role in Enhancing Adherence in Multimorbid Rheumatoid Arthritis

Marco Capodiferro¹, Daniele Domanico¹, Angelica Napoletano¹, Giulia Righetti², Patrizia Suppressa², Vincenzo Venerito¹, Giuseppe Lopalco¹, Florenzo Iannone¹, Fabio Cacciapaglia^1|2 | ¹Rheumatology Unit, Department of Precision and Regenerative Medicine and Jonian Area DiMePRe-J University of Bari, Italy; ²Department of Medicine and Surgery, Miulli General Hospital Acquaviva delle Fonti - LUM University Casamassima Bari Acquaviva delle Fonti, Bari, Italy

Aim. Poor adherence to treatment remains a significant barrier to effective disease management, particularly in inflammatory rheumatic diseases. Polypharmacy (defined as the use of more than five medications daily) is a known predictor of poor adherence and worse clinical outcomes. Rituximab (RTX), a second-line biologic disease-modifying antirheumatic drug (bDMARD), is widely used for the treatment of rheumatoid arthritis (RA) and exhibits the highest treatment persistence among bDMARDs in national registry data, often considered a last resort for patients who have failed to respond to several treatments. Administered uniquely via intravenous infusion and with long intervals between doses, RTX may support better adherence compared to other DMARDs; however, its adherence has never been explicitly explored. Therefore, we evaluated adherence to RTX, specifically examining its relationship with comorbidity burden and polypharmacy in patients with RA.

Patients and Methods. We conducted a pilot cross-sectional observational study including RA patients treated with RTX who met the 2010 ACR/EULAR classification criteria. Data were collected during routine outpatient visits starting in December 2024. Clinical information was obtained from medical records, including disease activity scores (DAS28, CDAI), patient-reported disability outcomes (HAQ-DI), and the Charlson Comorbidity Index (CCI). Adherence was measured using the 4-item Morisky Medication Adherence Scale (MMAS-4), with scores greater than 2 indicating good adherence. Statistical analyses were performed to identify relevant associations.

Results. Fifty RA patients were included (90% female; mean age 56.7 ± 9.1 years; median disease duration: 110 months). RTX was the median 4-line b/tsDMARD and was used as monotherapy in 80% of cases. Only 10 patients also received methotrexate, and 2 received leflunomide. Notably, only 10 patients (16.7%) were on corticosteroids. Median DAS28 and CDAI scores were 2.4 (IQR, 1.5–3.6) and 3 (IQR, 1–10), respectively, with nearly 80% of patients achieving low disease activity or remission. The median HAQ-DI was 0.62 (IQR 0.4–1.1), and 73% of patients had a score >0.5, indicating moderate functional impairment. The median CCI was 3 (IQR 2–4). Based on MMAS-4, 75% of patients were classified as adherent. No significant correlations were observed between adherence and disease activity scores, HAQ-DI, or CCI.

Conclusions. Our study found a high rate of adherence to RTX in RA patients, with most maintaining reasonable disease control despite moderate functional limitations and comorbidities. These findings, if confirmed, suggest that RTX may offer a favourable adherence profile, supporting its potential role in personalized treatment strategies for patients dealing with polypharmacy. References A Review of Risk Factors for Polypharmacy: Age, Level of Education, and Physician's Attitude - Gabriel Majewski et.al, Cureus. 2024 Oct Remission, response, retention and persistence to treatment with disease-modifying agents in patients with rheumatoid arthritis: a study of harmonised Swedish, Danish and Norwegian cohorts -Helga Westerlind et al., RMD Open. 2023 Sep