Background: Remission of rheumatoid arthritis (RA) is currently a reachable target in real-life settings under treat-to-target strategies, meta-analytical data showing an overall success of 16.3% for its 6-month DAS28 definition [1]. Baseline high levels of inflammation and activity markers have been consistently shown to negatively influence this endpoint.

Objectives: The study aimed to evaluate the prevalence of DAS28-defined remission in naïve RA patients after their first 6 months of b/tsDMARD treatment and whether the degree of baseline activity independently predicts treatment outcomes (remission, switch) in a real-life setting.

Methods: Medical records of naïve RA patients who initiated b/tsDMARDs (according to Romanian criteria [2]) from 20.12.2016 to 20.12.2021 were retrieved retrospectively from the database of the Clinical Center for Rheumatic Diseases in Bucharest, Romania. Children, cases with missing data (baseline and 6 months), patients who were previously exposed to b/tsDMARDs, patients exposed to b/tsDMARDs less than 6 months and patients who were not actually exposed to b/tsDMARDs were excluded. Prediction of dichotomous outcomes (remission and switch at 6 months) was evaluated using binary logistic regression.

Results: The study included 157 patients with established RA, mostly women (80.3%), 56.2±11.8 years-old on average. The group included predominantly positive rheumatoid factors (77.7%) and positive anti-citrullinated protein antibodies (81.5%), with only 12.1% both negative. At baseline, 58.0% were receiving one csDMARD (especially leflunomide - 49.7%, and methotrexate - 43.3%), 38.9% were receiving 2 csDMARDs, and 57.3% were on chronic oral glucocorticoids (7.6±4.4 mg/day on average). All patients had high baseline disease activity (average DAS28 of 6.3±0.8). Accordingly, all patients were initiated on either original/biosimilar TNF inhibitors (adalimumab - 22.3%; certolizumab - 7.0%; etanercept - 31.2%; golimumab - 1.3%; infliximab - 17.8%), other bDMARDs (abatacept - 3.8%; rituximab - 1.9%; tocilizumab - 6.4%) or tsDMARDs (baricitinib - 5.7%; tofacitinib - 2.5%). After 6 months, 29.3% of patients were in DAS28-defined remission, 22.9% in LDA, 35.7% in MDA and 12.1% in HDA. Therefore, 12.7% switched their initial bDMARD and 10.8% stopped b/tsDMARDs, because 10.8% exhibited primary non-responsiveness (PNR) and 11.5% had adverse events (7 dermatological conditions, 6 cases of non-tuberculosis pneumonia, 1 case of clinical pulmonary tuberculosis, 1 case of latent tuberculosis, 1 transaminitis, 1 gastric cancer, 1 neutropenia). High baseline levels of DAS28 were associated with a lower probability to attain DAS28-remission after 6 months (OR = 0.64) and with a higher probability to switch the initial b/tsDMARD due to PNR (OR = 2.44), suggesting that pharmaceutically influencing the inflammation cascade is not enough. Addition of b/tsDMARDs reduced at 6 months the prevalence of oral glucocorticoids to 28.0% (5.9±2.6 mg/day on average).

Conclusion: Although reachable, disease remission seems difficult to attain, despite using advanced therapies. High baseline levels of DAS28 are negative predictors for not attaining remission and switching of therapy due to PNR in real-life.

REFERENCES:

[1]Yu C et al. Clin Rheumatol. 2019; 38 (3): 727-738.

[2]Codreanu C et al. Biologicals. 2019; 62: 27-32.

Disclosure of Interests: None declared