Background Several reports have shown that rituximab may have some efficacy in patients with active ankylosing spondylitis (AS), mainly in tumor necrosis factor alpha (TNF-α) inhibitor naïve. No direct comparisons of rituximab and TNF-α inhibitors or non-steroid anti-inflammatory drugs (NSAIDs) are published.
Objectives To directly compare the effect of NSAIDs monotherapy and combinations of NSAIDs with rituximab and TNF-α inhibitors in patients with highly active AS in a prospective study.
Methods 20 patients (males-17, mean age 36.3±9.9 years) with highly active AS (BASDAI 6.19±1.48, ASDASESR 3.43±0.72) were treated with rituximab (two infusions, 500-1000 mg depending on body weight and AS activity, separated by 14 days gap) which was added to previously taken NSAID. 35 patients (males-30, mean age 34.3±8.6 years, BASDAI 5.59±1.19, ASDASESR 3.22±0.74) received treatment with combination of TNF-α inhibitors (infliximab, etanercept, adalimumab) and NSAIDs. 35 patients (males-30, mean age 33.4±9.3 years, BASDAI 5.95±1.26, ASDASESR 3.32±0.60) received monotherapy with NSAIDs. Share of AS patients who achieved ASAS 20 response on week 24 was the primary endpoint.
Results At week 24, in NSAIDs group mean BASDAI score was 5.22±1.14, with 11 (31.4%) patients satisfying the ASAS 20 response criteria. In rituximab group, mean BASDAI score was significantly lower compared to NSAIDs group (3.70±0.91, p<0.05), 15 (75%) patients reached ASAS20 response. Mean BASDAI score in patients treated with TNF-α inhibitors was the lowest (2.03±0.64) compared both to NSAIDs (p<0.05) and rituximab (p<0.01), with 33 (94.3%) patients achieving ASAS20 response.
Conclusions Combined therapy with NSAIDs and rituximab is more effective in treating active AS than NSAIDs alone, but less effective compared to combination of NSAIDs and TNF-α inhibitors.
Disclosure of Interest None declared