Infliximab in ankylosing spondylitis: alone or in combination with methotrexate? A pharmacokinetic comparative study
1 Université François-Rabelais de Tours, Centre National de la Recherche Scientifique UMR 6239 GICC (Génétique Immunothérapie Chimie et Cancer), 3 rue des Tanneurs, F-37041 Tours Cedex 1, France
2 Service de Rhumatologie, Centre Hospitalier Régional et Universitaire de Tours, avenue de la République, F-37044 Tours Cedex 9, France
3 Université de Franche-Comté, EA 4266 API (Agents Pathogènes et Inflammation), Hôpital Saint Jacques, 2 place Saint-Jacques, F-25030 Besançon Cedex, Besançon, France
4 Service de Rhumatologie, Centre Hospitalier Régional et Universitaire de Besançon, Hôpital Jean Minjoz, 3 boulevard Alexander Fleming, F-25030 Besançon Cedex, Besançon, France
5 Laboratoire de Pharmacologie-Toxicologie, Centre Hospitalier Régional et Universitaire de Tours, 2 boulevard Tonnellé, F-37044 Tours Cedex 9, France
6 Institut National de la Santé et de la Recherche Médicale CIC 202, 2 boulevard Tonnellé, F-37044 Tours Cedex 9, Tours, France
Arthritis Research & Therapy 2011, 13:R82 doi:10.1186/ar3350Published: 3 June 2011
Methotrexate (MTX) has been shown to modify infliximab pharmacokinetics in rheumatoid arthritis. However, its combination with infliximab in the treatment of ankylosing spondylitis (AS) is not recommended. The objective of this study was to examine the influence of MTX on infliximab exposure in patients with AS.
Patients with AS patients who had predominantly axial symptoms were randomised to receive infliximab alone (infusions of 5 mg/kg at weeks 0, 2, 6, 12 and 18) or infliximab combined with MTX (10 mg/week). Infliximab concentrations were measured before and 2 hours after each infusion and at 1, 3, 4, 5, 8, 10, 14 and 18 weeks. We estimated individual cumulative area under the concentration versus time curves (AUC) for infliximab concentration between baseline and week 18 (AUC0-18). Clinical and laboratory evaluations were performed at each visit. The Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) score was the primary end point for clinical response.
Twenty-six patients were included (infliximab group: n = 12, infliximab + MTX group: n = 14), and 507 serum samples were available for measurement of infliximab concentration. The two groups did not differ with regard to AUC0-18 or evolution of BASDAI scores and biomarkers of inflammation.
The combination of MTX and infliximab does not increase the exposure to infliximab over infliximab alone in patients with AS.