Effectiveness and safety of TNF-α inhibitors and il-6 pathway antagonists for refractory Takayasu arteritis

Standard therapy for Takayasu arteritis (TA) usually comprises glucocorticoids in combination with cytotoxic agents. However, despite ongoing therapy disease activity remains high in some patients. In these cases, biological therapy is prescribed. The aim – to evaluate the efficacy and safety of tumor necrosis factor α inhibitors (TNFi) and interleukin 6 (IL-6) pathway antagonists (anti-IL-6) therapy in TA patients refractory to conventional therapy. Subjects and methods. In this single center retrospective cohort study, we included 36 female adult patients aged from 20 to 57 years (54 courses of biological therapy) with TA, diagnosed in accordance with the ACR classification criteria (1990 and/or 2022) and/or Chapel Hill Consensus Conference (2012) definition. All patients were on biologics due to resistance to corticosteroids and cytotoxic agents. Results. A total of 54 courses of TNFi ( n =29) and anti-IL-6 ( n =25) inhibitors were analyzed. The median duration of biological therapy was 14 (9; 32) months, with a median duration of 14 (8; 32) months for TNFi and 13 (7; 32) months for anti-IL-6. The remission rate showed no significant difference between TNFi (79%) and anti-IL-6 (84%; p =0.736) treatment groups. The incidence of relapses was higher with TNFi, although the difference between groups did not reach statistical significance (36% and 14%, respectively; p =0.291). Relapse was established after 15 (10; 22) weeks for TNFi and after 22 (13; 31) weeks for anti-IL-6 ( p =0.919). TNFi and anti-IL-6 had a comparable steroid-sparing effect: the median dose of GC in terms of prednisolone decreased from 13 to 8 mg (p=0.009), and from 15 to 8 mg ( p =0.026), respectively. Factors associated with achieving TA remission were assessed using a logistic regression model. None of the parameters (age at the start of biological therapy, duration of disease before the start of biological therapy, class of biological therapy) were associated with achieving remission of TA. Adverse events (AEs) occurred in 22% of cases resulting in therapy discontinuation in 13% of patients. Conclusion. Our study demonstrated the high effectiveness of TNFi and anti-IL-6 in patients with refractory to conventional immunosuppressive therapy TA: remission was achieved in 80% of cases, allowing for a reduction in glucocorticoid dosage. The safety profile of TNFi and antiIL-6 was acceptable. However, AEs occurred slightly more frequently in the TNFi group.