Attempts to diagnose ankylosing spondylitis (AS) earlier based on clinical manifestations and based on MRI which can depict inflammation without structural damage has led to the concept of axial spondyloarthritis (axSpA) with its two subentities non-radiographic axSpA (nr-axSpA) and AS. However, a clear distinction between nr-axSpA and AS based on plain radiographs of the sacroiliac joints continues to proves difficult as recent studies have confirmed, supporting the concept of axial SpA. The management recommendation by ASAS/ EULAR have focussed in the past primarily on AS but can be extended to the entire spectrum of axial SpA. The recent “treat-to-target” recommendations for SpA already included the entire spectrum of axial SpA. Patient education, physical therapy and exercise are important aspects of disease management. Medical treatment consists of NSAID therapy as first line of medical therapy. If inflammatory back pain is the leading symptom, a proportion of patients becomes free of symptoms with NSAID therapy alone. Importantly, several NSAIDs should be tried because response to and tolerance of NSAIDs may differ among patients. For patients with axial SpA who do not sufficiently respond to NSAIDs, TNF inhibitors (TNFi) are the second line of medical therapy. Using TNFi approximately 40-50% of patients have a very good clinical response as assessed by the ASAS 40 response criterion. Between 20-30% of patients go into remission during TNFi therapy. Although no head to head comparison is available there is no evidence of different effectiveness of the approved TNFi in the treatment of axial symptoms. TNFi work best if there is objective evidence of inflammation such as elevated CRP or MRI inflammation. Shorter disease duration or younger age are also important determinants for a good treatment response. TNFi are also effective in treating enthesitis, peripheral synovitis, dactylitis and reducing the frequency of uveitis in axial SpA. Of the 5 TNFi approved for AS, 3 have been approved for nr-axSpA as well. Synthetic DMARDs are not effective in treating axial inflammation in SpA but can be effective for the therapy of peripheral synovitis with sulfasalazine being the preferred drug. The ultimate treatment target in axial SpA is clinical remission, and the abrogation of inflammation seems to play an important role in achieving this goal. Whether TNFi may also inhibit the formation of new syndesmophytes in the spine is still unclear, uncontrolled observations suggest that this may be the case after a period of 4 years of treatment. Similarly, it is still unclear whether NSAIDS can retard radiographic progression of given continuously because of contradictory study results. Low dose steroids do not have a place in the management of axial SpA but short courses of high doses may be effective (expert opinion only). Treatment options for patients who do not respond sufficiently to either NSAIDs or TNFi are currently limited to analgetics. Other biologics such as ustekinumab targeting IL12/23 and secukinumab targeting IL-17 have been investigated with promising results. Since the clinical trial programme (phase 3 trial completed) is already advanced, secukinumab may be the next non-TNFi biologic to be approved for the treatment of AS/ axial SpA in the future.
Disclosure of Interest M. Rudwaleit Consultant for: Abbvie, BMS, Janssen, MSD, Pfizer, UCB, Speakers bureau: Abbvie, Janssen, MSD, Pfizer, Roche, UCB