Hindawi Publishing Corporation Mediators of Inlammation Volume 2013, Article ID 289845, 9 pages http://dx.doi.org/10.1155/2013/289845 Clinical Study Infliximab Dose Reduction Sustains the Clinical Treatment Effect in Active HLAB27 Positive Ankylosing Spondylitis: A Two-Year Pilot Study Boel Mörck, 1 Rille Pullerits, 1 Mats Geijer, 2,3 Tomas Bremell, 1 and Helena Forsblad-d’Elia 1 1 Department of Rheumatology and Inlammation Research, he Sahlgrenska Academy at Gothenburg University, Guldhedsgatan 10A, 41346 Gothenburg, Sweden 2 Department of Radiology, Sahlgrenska University Hospital, Bruna str˚ aket 11B, 41345 Gothenburg, Sweden 3 Center for Medical Imaging and Physiology, Sk˚ ane University Hospital, Lund University, 22185 Lund, Sweden Correspondence should be addressed to Rille Pullerits; rille.pullerits@rheuma.gu.se Received 29 May 2013; Accepted 2 August 2013 Academic Editor: Chaim Putterman Copyright © 2013 Boel M¨ orck et al. his is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. he rationale of the study was to evaluate the eicacy of inliximab (IFX) treatment in patients with ankylosing spondylitis (AS) and to determine whether IFX dose reduction and interval extension sustains the treatment efect. Nineteen patients were included and treated with IFX 5mg/kg every 6 weeks for 56 weeks. All patients concomitantly received MTX with median dose 7.5mg/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. he ≥50% improvement at week 16 from baseline of BASDAI was achieved in 16/19 (84%) patients. Signiicant reductions in BASDAI, BASFI, and BASMI scores, decrease in ESR and CRP, and improvement in SF-36 were observed at weeks 16 and 56. he MRI-deined inlammatory changes in the sacroiliac joints disappeared in 10/15 patients (67%) already at 16 weeks. IFX treatment efect was sustained throughout the second year ater IFX dose reduction and interval extension. We conclude that IFX treatment is efective in well-established active AS and a dose reduction sustains the treatment efect. hese observations are of clinical importance and open the opportunity to reduce the drug costs. his trial is registered with ClinicalTrials.gov NCT01850121. 1. Introduction Ankylosing spondylitis (AS) is a chronic, progressive inlam- matory disease that primarily afects the spine and sacroiliac joints. he disease has a prevalence of about 0.55% of the European population [1, 2] and is closely associated with HLA-B27 positivity. he disease afects mostly young individuals in the third and fourth decade of their life and may therefore have a major impact on their work ability, which is associated with increased costs to the patient and the healthcare system [3]. Disease modifying antirheumatic drugs (DMARDs), including methotrexate and sulfasalazine, have not shown eicacy in treating the axial manifestations of AS but may be beneicial in treating peripheral joint disease [4]. NSAIDs along with patient educational programs, regular physiother- apy, and exercises have been recommended as the standard therapy for axial AS. TNF-alpha antagonists have made it possible to notably improve the health status in AS patients. he eicacy of TNF antagonists has been demonstrated in several short-term clinical studies [5] as well as in long- term studies [6–8]. Although compelling data is increasing indicating that inliximab is efective for treatment of AS, most randomized, placebo-controlled studies have evaluated a treatment dose of 5 mg/kg every 6 weeks. A few reports have been published showing that inliximab in a low-dose regimen (3 mg/kg) is also efective in suppressing signs and symptoms of active AS [9–15]. However, the need for dose escalation up to 5 mg/kg due to partial treatment efect has been reported highly varying in diferent study cohorts [13– 15]. Dose escalation was necessary in 15% and 18% of patients as reported by Maksymowych et al. [10] and Jois et al. [14], respectively. In contrast, in two other studies it was found that 61%–63% of patients required dose escalation [12, 15].