Maksymowych WP et al. (2008) Beneficial effects of adalimumab on biomarkers reflecting structural damage in patients with ankylosing spondylitis. J Rheumatol 35: 2030–2037

Therapy with anti-tumor necrosis factor agents improves the symptoms of ankylosing spondylitis (AS); however, evaluation of these agents' disease-modifying capability in placebo-controlled trials is hampered by limitations of the modified Stoke AS Spinal Score, which, despite its 'gold standard' status, has poor capacity to detect radiographic progression. A recent randomized, placebo-controlled study investigated the effects of adalimumab on biomarkers thought to be predictive of structural damage in patients with AS.

Patients with long-standing active AS received 40 mg of adalimumab (n = 38) or placebo (n = 44) every other week for 24 weeks. Adalimumab treatment significantly decreased concentrations of serum matrix metalloproteinase 3 and urinary C-telopeptide fragment of type II collagen; however, it had no effect on N-telopeptide of type I collagen, a serum biomarker of bone resorption, reinforcing findings from a previous study of infliximab. Interestingly, a strong correlation was noted between C-telopeptide fragment of type II collagen and C-reactive protein levels, suggesting that adalimumab reduces cartilage turnover via amelioration of inflammation. A significant, but weaker, correlation between matrix metalloproteinase 3 and C-reactive protein might be explained by the limited number of patients with peripheral joint involvement. A notable lack of correlation between biomarker levels and MRI findings suggests that they measure separate aspects of disease progression.

The capacity of adalimumab to suppress biomarkers associated with AS progression and the absence of correlation with MRI findings suggests that future studies should measure both outcome parameters.