Background/Purpose: Despite the progress in the treatment of ankylosing spondylitis (AS), a significant number of patients does not achieve low disease activity (LDA). The aim of this study was to estimate the size of unmet needs in the treatment of AS, using non-steroidal anti-inflammatory drugs (NSAIDs), and/or anti-cytokine therapy, in a long-term observational study.

Methods: Between January 2003 and December 2017, 220 patients with AS were diagnosed and followed-up in a tertiary outpatient rheumatology clinic. All patients fulfilled the 1984 modified New York criteria for AS. They were followed-up at predefined times and were naïve to biological treatment with anti-tumor necrosis factors (anti-TNFs) and interleukin (IL)-17 inhibitors. The patients were treated according to the European, United States and Canadian guidelines for AS. More specifically, NSAIDs including selective inhibitors of cyclooxygenase-2 were introduced. In addition, the following anti-TNFs were used: adalimumab (ADA), certolizumab, etanercept (ETN), golimumab and infliximab (INF). We also used secukinumab. During follow-up, clinical and laboratory findings, as well as treatment decisions and strategies, adverse drug reactions, reasons of termination or changing therapy, disease complications and comorbidities were all recorded. Disease activity was measured using the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and the Ankylosing Spondylitis Disease Activity Score (ASDAS), using the C-reactive protein.

Results: All patients had an active disease (BASDAI>4 and ASDAS> 2.1) and received at least two NSAIDs for 3 months. The anti-TNF of first choice was INF (51%), followed by ADA (27%) and ETN (22%). During the follow-up period, 18 patients were lost and 4 never received anti-TNF therapy due to various comorbidities. Thus, the final results are referred to 198 patients. Among them 12 (6%) continued receiving NSAIDs with significant clinical improvement and sustained LDA. However, 4 patients from this group never achieved LDA neither received anti-TNF therapy because they refused such treatment. On the other hand, 186 (94%) were treated with anti-TNFs. The majority of them demonstrated sustained LDA for a long period of time. However, from this group, 16 patients never achieved LDA despite they received 2 or 3 anti-TNFs or IL-17 inhibitors. Thus a total of 20 (10.1%) patients in our study never achieved LDA.

Conclusion: This is the first study aiming to estimate the gap and the size of unmet needs in AS patients using the international guidelines and recommendation for AS treatment. We found that the size of gap and unmet needs for AS treatment is 10%.

« Back to 2018 ACR/ARHP Annual Meeting

ACR Meeting Abstracts - https://acrabstracts.org/abstract/unmet-needs-in-the-treatment-of-ankylosing-spondylitis-a-long-term-observational-study-from-a-single-university-center/