Factors affecting drug survival of an alternative TNF inhibitor and secukinumab in patients with ankylosing spondylitis switching from the first TNF inhibitor.

When switching the drug from the first TNFi in patients with AS, an alternative TNFi could be preferable in patients with higher CRP levels or syndesmophytes, or current smokers, whereas SEC could be a better choice in patients who presented primary failure of the first TNFi in terms of drug survival.