Five TNF inhibitor (TNFi) agents are marketed for spondyloarthritis (SpA): 1 soluble receptor (SR) and 4 monoclonal antibodies (mAbs). From 15% to 30% of patients stop the first TNFi in the first 2 years, but we lack recommendations on the choice of the second TNFi. The aim here was to assess drug survival of a second TNFi in SpA and its determinants.

This was a multicenter observational study of SpA patients who started a first TNFi in 2013 and 2014 and were followed to 2018. For the first and second TNFi, we retrospectively collected data on initiation and discontinuation dates, type of TNFi, and reasons for withdrawal. Kaplan–Meier plots and log-rank tests were used to compare drug survival. Factors associated with drug survival of the second TNFi were analyzed by univariate Cox regression analyses.

We included 244 patients. During a follow-up of 7,838 patient-months, 101 (41%) received 1 TNFi, and 143 (59%) switched to a second TNFi. Mean drug intake duration was significantly greater with the first than second TNFi: 21.7 (SD 19.6) and 15.4 (SD 13.6) months (P<0.001). When switching to another mAb or from an SR to an mAb (or the reverse), mean drug survival did not differ: 14.4 (SD 12.7) and 16 (SD 14.1) months (P=0.35). Factors associated with retaining the second TNFi were male sex (P=0.054) and age<41 years at SpA diagnosis (P=0.022). On multivariable analysis, only age<41 years at diagnosis remained independently associated with maintenance of the second TNFi.

In SpA patients, drug survival is significantly longer with the first than second TNFi. Male sex and age<41 years at diagnosis were associated with retaining the second TNFi.