Efficacy and safety of conventional disease-modifying antirheumatic drugs in VEXAS syndrome: real-world data from the international AIDA network

Background: VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome is an adult-onset autoinflammatory condition resulting in severe, often treatment-refractory inflammation. Currently, there are no established treatment guidelines for VEXAS syndrome. Objectives: To assess the efficacy and safety of conventional disease-modifying antirheumatic drugs (cDMARDs) in a cohort of VEXAS patients. Methods: Data from VEXAS patients were obtained from the International AIDA Network VEXAS registry. Results: Data from 36 VEXAS patients were evaluated, with 28 (77.8%) treated with cDMARDs as monotherapy - and concomitant glucocorticoids (GC) - and 8 (22.2%) receiving a combination of different cDMARDs plus GC. Complete response (CR), partial response (PR), and failure to cDMARDs monotherapy were reported in 4/22 (18.2%), 11/22 (50%), and 7/22 (31.8%) courses, respectively. All patients were treated with GCs at the start of cDMARD monotherapy, and no GC discontinuation was observed later. No significant differences were observed in the GC dosage from the start of cDMARDs to the 3-month (p = 0.43), 6-month (p = 0.31), and 12-month (p = 0.21) visits. Conversely, the GC sparing resulted to be statistically significant when using methotrexate (p = 0.02). As for cDMARDs combinations, no cases achieved CR, while PR was observed in 5/9 (55.6%). Seventeen adverse events were reported, seven of which led to discontinuation. Conclusion: Many VEXAS patients report a partial benefit from cDMARDs, while a smaller yet not negligible number of patients exhibit a CR; cDMARDs remain a viable option for this disorder, especially when the initial GC dosage is low and the need for a steroid-sparing effect is not immediately urgent.