Lack of Efficacy of Abatacept in Axial Spondylarthropathies Refractory to Tumor-necrosis-factor Inhibition

Objective: To assess the efficacy of abatacept in patients with axial spondyloarthropathies who had failed TNFα antagonist therapy.

Methods: Consecutive patients fulfilling criteria for active axial spondyloarthropathy, despite at least two previous TNFα antagonists, were treated with abatacept (10mg/kg) given on days 1, 15, and 29, then every 28 days until week 24. Clinical and laboratory outcome criteria were assessed monthly for 6 months.

Results: Seven patients were treated and followed, all women (median age, 39 years; median disease duration, 12 years), five with ankylosing spondylitis and two with undifferentiated spondyloarthropathy. After 6 months of abatacept therapy, no patient had an at least 50% decrease in the BASDAI; a single patient had an at least 2 cm decrease in the BASDAI (-3.8 cm; -49.3%). No significant changes were observed in pain or patient global assessment scores. Inflammatory back pain persisted in all seven patients. When present, enthesitis improved in most patients. Improvements in spinal mobility measures occurred in two patients. There were no clinically significant adverse events.

Conclusion: A 6-month regimen of abatacept did not meaningfully improve disease activity, function, or other disease parameters in seven patients with axial spondyloarthropathies. These preliminary results do not suggest a strong efficacy of abatacept in axial forms of spondyloarthropathies.