Failure of first anti-TNF agent in Takayasu's arteritis: to switch or to swap?

Biologic drugs (bDMARD), especially TNF-α-inhibitors (TNFi), are used in refractory Takayasu's arteritis (TAK) patients. Up to 23% of patients are switched to a different bDMARD because of inefficacy. No data are available on which strategy is more efficient after TNFi failure. The aim of our study is to evaluate whether a switch or swap strategy should be preferred in TAK patients failing TNFis. TAK patients treated with a second bDMARD after the failure of the first TNFi were identified from 3 referral centres. Patients were classified as switch if treated with a different TNFi, and swap if treated with a non-TNFi bDMARD. Baseline features were evaluated. Efficacy and safety of the second bDMARD at 6 and 12 months were assessed and a comparison between switch and swap patients was made. Twenty-four TAK patients were identified. Eleven patients (46%) were switched and 13 patients (54%) were swapped (12 to tocilizumab, 1 to ustekinumab). Baseline features of patients in the 2 groups were comparable. At 12 months, the second bDMARD was suspended in 4 switch (36%) and in 5 swap (42%) patients. Second biologic drug survival and relapse-free survival were equivalent between the two groups at 6 and 12 months. A vascular worsening was observed in 4 switch (40%) and 2 swap (25%) patients. Severe infections, myocardial infarction, ischemic stroke or cancer were recorded in no patient. Our retrospective study suggests that in first-line TNFi failure TAK patients both switch and swap strategies can be considered suitable approaches.