A multicenter, open-label, long-term study of three-year infliximab administration in Japanese patients with ankylosing spondylitis.

OBJECTIVE

To investigate the efficacy, safety, and pharmacokinetics of infliximab (IFX) in Japanese patients with active ankylosing spondylitis (AS).

METHODS

In this multicenter open-label study, IFX was infused at 5 mg/kg to 33 Japanese patients with active AS using or intolerable to non-steroidal anti-inflammatory drugs (NSAIDs) at Weeks 0, 2, and 6, and then every six weeks for approximately three years (mean: 149.5 weeks).

RESULTS

Assessment in Ankylosing Spondylitis (ASAS) 20 response at Week 24 (primary endpoint) was 97.0% (32/33) and was thereafter maintained at approximately 90% over the three-year study period. Improvements in range of motion, physical function, inflammatory parameters, and quality of life (QOL) were all maintained throughout the three-year study period. A serum IFX level of ≥5 μg/mL was maintained with six-week infusion intervals, and only two patients (6.1%) developed antibodies to IFX. Specific adverse events in AS patients were not observed.

CONCLUSION

These findings suggest that a 5 mg/kg administration of IFX at six-week intervals to Japanese patients with active AS is safe, effective and provides long-term therapeutic benefits.