Short-term efficacy of combination methotrexate and infliximab in patients with ankylosing spondylitis: a clinical and magnetic resonance imaging correlation.

OBJECTIVE

To examine the short-term efficacy and safety of MTX in combination with infliximab compared with infliximab and placebo in the treatment of AS using MRI to monitor its effect.

METHOD

Thirty-eight subjects with active AS were randomized to receive MTX (MTX group) or placebo (placebo group) for 22 weeks. Both groups received infliximab for three infusions of 5 mg/kg at week 16, 18 and 22 and were followed up until week 30. MRI changes in the spine were assessed before and after infusion.

RESULTS

The Assessments in Ankylosing Spondylitis (ASAS) 20 response at week 16 was 5.4% in the MTX group vs 15.8% in the placebo group (P = 0.17). In the MTX group, 5.4, 31.6, 52.6 and 63.2% of patients vs 15.8, 21.1, 57.9 and 68.4% patients in the placebo group achieved ASAS20 at week 16, 18, 22, 30, respectively. There were no significant differences between the two groups at any time points. Likewise, the secondary outcome showed no significant differences between the two groups. MRI changes in 31 subjects showed an overall improvement of 36.4% but the changes were not significant between the two groups.

CONCLUSIONS

Combination MTX with infliximab is as safe and as effective as infliximab monotherapy in the treatment of AS with a significant improvement in ASAS20 and in the different core sets in assessment. MRI improvements were also seen. However, there was no additional clinical or MRI improvement with the addition of MTX to infliximab in AS.