Low doses of etanercept can be effective in ankylosing spondylitis patients who achieve remission of the disease

This study aims to explore the effectiveness of low dose of etanercept (ETN) in patients with ankylosing spondylitis (AS) who achieve a good control of their disease in daily clinical practice. This is a case series of AS patients treated with ETN. According to the judgment of the treating rheumatologist and patient's preferences, a dose reduction was done in those patients who achieved a good control of their disease defined by Bath ankylosing spondylitis disease activity index (BASDAI) < 4 and C-reactive protein normal values. Fifty-one AS patients treated with ETN were identified and 16 of them (32%) were on dose reduction regimen. Several regimens of dose reduction were used. These patterns were fixed and they did not change along the time. Mean time receiving ETN before adjusting the dose was 17 +/- 12 months. Mean follow-up after dose change was 21 +/- 21 months. At this point, all the patients in whom dose reduction was done remained in the low-dose regimen. Median BASDAI (range) at starting the low-dose regimen and 6 months later were 1.6 (0.9-2.4) and 1.4 (0.3-3.2), respectively. Median CRP values (range) at starting the low dose regimen and 6 months later were 1 mg/l (0.1-2.8), and 1.3 mg/l (0.3-4.1), respectively. Other disease-related variables also remained unchanged. Patients with follow up at 12 and 24 months and longer remained in clinical remission with BASDAI values < 2 and normal CRP values. Our data suggest that AS patients in clinical remission can use low doses of ETN without increasing disease activity. So, it can be a promising strategy but additional studies are needed to prove it.