At week 58, a greater proportion of patients treated continuously achieved an ASAS20 response than patients in the on-demand group. under placebo. Long-term efficacy is maintained when infliximab is administered every 6C8 weeks. Consensus international guidelines for the initiation and the use of this expensive treatment are available. Some questions remain, including the long-term safety, in particular the risk of lymphoma, and the potential influence of infliximab on radiological progression which is not currently demonstrated. Despite these concerns, infliximab has revolutionized the management of AS and represents a considerable therapeutic advancement in this disabling disease. According to the clinical trials and the extension protocol studies, the recommended infliximab regimen is an intravenous infusion of 5 mg/kg at weeks 0, 2, and 6, 360A followed by maintenance infusions at six- or eight-week intervals.40,92 Most studies evaluated the efficacy of infliximab in AS at a 5 mg/kg dosage. One study tried the medication at a lower dosage, 3 mg/kg, with favorable results.44 However, in a small study involving six patients with SpA, response to 3 mg/kg was inferior to 5 mg/kg.93 This question is relevant since anti-chimeric antibodies may occur with the use of infliximab.40 In RA, it is thought that methotrexate (MTX) reduces the incidence of anti-chimeric 360A antibodies and this associated medication may lower the incidence of acute infusion reaction to infliximab and finally, prevent progressive loss of efficacy. However, we do not have proof that MTX may be useful in AS patients treated by infliximab. One randomized controlled trial conducted in the UK evaluated the response to MTX (7.5C10 mg weekly) + infliximab (5 mg/kg given at weeks 0, 2, 6, and then at weeks 14 and 22) compared with MTX + 360A placebo. A higher proportion of patient in the MTX + infliximab group 360A reached an ASAS20 360A response compared to the MTX + placebo group (50% versus 21%), and the association of MTX did not allow to prolong the response to infliximab. Indeed, in this study, due to a longer interval between infliximab infusions (eight weeks after the induction treatment regimen at weeks 0, 2, and 6), some patients had a flare of their disease.94 Another multicenter study conducted in France specifically evaluated the need for the patient to be treated continuously by infliximab or only in case of relapse, and the potential benefit of associated MTX treatment. 247 Rabbit polyclonal to ACAD9 patients participated in this study: 124 received infliximab (5 mg/kg) every six weeks and 123 received on-demand treatment (based upon symptom recurrence). In this latter group, 62 patients received associated treatment with MTX and 61 infliximab alone. At week 58, a greater proportion of patients treated continuously achieved an ASAS20 response than patients in the on-demand group. The association of MTX to infliximab did not improve the proportion of ASAS20 responders. Thus, this study indicates that infliximab is more efficacious when administered continuously (every six weeks) and that the addition of MTX provides no substantial benefit.95 A third study in UK confirms these results: in a randomized placebo controlled study, 38 AS patients received either infliximab + MTX or infliximab + placebo. The ASAS 20 response did not differ between the two groups as well as the improvement in MRI spinal score.96 Infliximab may suppress active signs of inflammation on MRI, suggesting that the treatment has the potential to slow down the.