Emergence of severe spondyloarthropathy-related entheseal pathology following successful vedolizumab therapy for inflammatory bowel disease

Objectives Vedolizumab (VDZ) blocks α4β7 integrin and is licenced for the treatment of IBD. It has been associated with mild SpA-related features, including sacroiliitis and synovitis. Herein we report a series of cases demonstrating the emergence of severe SpA-associated enthesitis/osteitis following successful IBD therapy with VDZ. Methods We evaluated 11 VDZ-treated patients with IBD across seven centres who developed severe active SpA and/or enthesopathy, with the aim of characterizing the VDZ-associated SpA or entheseal flares. Imaging features demonstrating particularly severe disease were recorded. Results De novo SpA developed in 9 of 11 patients and flare of known SpA in 2 patients, with 4 patients requiring hospitalization due to disease severity. Available data showed that one of seven cases were HLA-B27 positive. The median time from VDZ initiation to flare was 12 weeks, with IBD well controlled in 7 of 10 patients (no data for 1 patient) at flare. Severe SpA enthesitis/osteitis was evident on MRI or US, including acute sacroiliitis (n = 5), extensive vertebral osteitis (n = 1), peri-facetal oedema (n = 1) and isolated peripheral enthesitis (n = 3). Due to arthritis severity, VDZ was discontinued in 9 of 11 patients and a change in therapy, including alternative anti-TNF, was initiated. Conclusion Severe SpA, predominantly HLA-B27 negative, with osteitis/enthesitis may occur under successful VDZ treatment for IBD, including in subjects with prior anti-TNF therapy for intestinal disease.