Infliximab dose reduction sustains the clinical treatment effect in active HLAB27 positive ankylosing spondylitis: a two-year pilot study

Abstract

The rationale of the study was to evaluate the efficacy of infliximab (IFX) treatment in patients with ankylosing spondylitis (AS) and to determine whether IFX dose reduction and interval extension sustains the treatment effect. Nineteen patients were included and treated with IFX 5 mg/kg every 6 weeks for 56 weeks. All patients concomitantly received MTX with median dose 7.5 mg/weekly. During the second year, the IFX dose was reduced to 3 mg/kg every 8 weeks. Eighteen patients completed the 1-year and 15 patients the 2-year trial. The ≥50% improvement at week 16 from baseline of BASDAI was achieved in 16/19 (84%) patients. Significant reductions in BASDAI, BASFI, and BASMI scores, decrease in ESR and CRP, and improvement in SF-36 were observed at weeks 16 and 56. The MRI-defined inflammatory changes in the sacroiliac joints disappeared in 10/15 patients (67%) already at 16 weeks. IFX treatment effect was sustained throughout the second year after IFX dose reduction and interval extension. We conclude that IFX treatment is effective in well-established active AS and a dose reduction sustains the treatment effect. These observations are of clinical importance and open the opportunity to reduce the drug costs.

Trial registration: ClinicalTrials.gov NCT01850121.

Figure 1

Flow chart of patient inclusion and dropouts.

Figure 2

Change in SPARCC scores over time. Box plots show the 25th and 75th percentiles. Horizontal solid lines within boxes indicate medians and vertical bars indicate the 5th and 95th percentiles.

Figure 3

Change in BASDAI, BASFI, and BASMI scores over time. Box plots show the 25th and 75th percentiles. Horizontal solid lines within boxes indicate medians and vertical bars indicate the 5th and 95th percentiles.

Figure 4

(a) A representative MRI study at inclusion (top row) with bilateral inflammatory changes (arrows). There is a 2 × 3 cm high signal intensity lesion on the sacral side of the left sacroiliac joint on the STIR images (coronal and axial) with corresponding low signal intensity on the coronal T1-weighted image. At the right sacroiliac joint, there are smaller and more subtle lesions on both sides of the joint. There are sclerotic changes along the left joint (arrowheads). At 16 weeks (bottom row), no oedematous lesions can be seen. (b) An MRI study showing bilateral sacroiliitis in an AS patient at inclusion and at 16 weeks. At inclusion, there are bilateral inflammatory changes on the MRI images (top row, arrows). At the right sacroiliac joint, there is a 1 × 1 cm high signal intensity lesion in the sacrum on the STIR images (coronal and axial) with corresponding low signal intensity on the coronal T1-weighted image. On the left, there are smaller and more subtle lesions on both sides of the joint. There are sclerotic changes along the right sacroiliac joint. At 16 weeks (bottom row), no oedematous lesions can be seen.

Figure 5

The patients' health related quality of life measured by SF-36. The graph shows the mean scores for the eight SF-36 domains for the normal population and the patients with AS at baseline, at 16 weeks, and at 56 weeks. A significant improvement in patients' health related quality of life was observed at weeks 16 and 56 as compared with baseline.