Radiographic findings following two years of infliximab therapy in patients with ankylosing spondylitis.

OBJECTIVE: To evaluate the effect of infliximab on progression of structural damage over 2 years in patients with ankylosing spondylitis (AS).

METHODS: In the Ankylosing Spondylitis Study for the Evaluation of Recombinant Infliximab Therapy (ASSERT), a randomized, double-blind, placebo-controlled trial of the efficacy of infliximab compared with placebo, 279 patients with active AS received either placebo through week 24 and then infliximab 5 mg/kg from week 24 through week 96 (n=78) or infliximab 5 mg/kg from baseline through week 96, administered every 6 weeks after a loading dose (n=201; these patients were the focus of the radiographic analyses). Radiographic findings in patients from the ASSERT trial were indistinguishable from those in a historical control cohort of patients who had no prior use of anti-tumor necrosis factor agents (from the Outcome in Ankylosing Spondylitis International Study [OASIS] database; n=192). Radiographic progression of structural damage from baseline to the 2-year followup was scored using the modified Stoke Ankylosing Spondylitis Spine Score (mSASSS). All images were scored in one batch.

RESULTS: Median changes in the mSASSS from baseline to year 2 were 0.0 for both the OASIS and the ASSERT cohorts (P=0.541). Mean changes in the mSASSS were also similar between the OASIS and ASSERT cohorts (mean+/-SD change over 2 years 1.0+/-3.2 and 0.9+/-2.6, respectively). In addition, results from sensitivity analyses did not show a statistically significant difference in the mSASSS between the OASIS and ASSERT cohorts.

CONCLUSION: AS patients who received infliximab from baseline through week 96 did not show a statistically significant difference in inhibition of structural damage progression at year 2, as assessed using the mSASSS scoring system, when compared with radiographic data from the historical control OASIS cohort. Improvements in clinical outcomes and spinal inflammation have been previously demonstrated with the use of infliximab therapy.