Infliximab monotherapy in Japanese patients with moderate-to-severe plaque psoriasis and psoriatic arthritis. A randomized, double-blind, placebo-controlled multicenter trial

BackgroundA clinical trial of infliximab in psoriasis has not yet been performed in Asian populations, although infliximab has been approved for the indications of psoriatic arthritis and plaque psoriasis in the US and the EU.ObjectiveThis study aims to validate the efficacy and safety of infliximab in Japanese patients with plaque psoriasis and psoriatic arthritis.MethodsPatients with moderate-to-severe psoriasis, including psoriatic arthritis, were randomized to the induction therapy (Weeks 0, 2 and 6) with infliximab 5 mg/kg (n = 37) or placebo (n = 17). For the maintenance therapy, infliximab was administered every 8 weeks from Week 14 to Week 62 in the infliximab group, and placebo was switched to infliximab in the placebo group starting at Week 16. The primary efficacy endpoint was the proportion of patients who had achieved at least 75% improvement in the psoriasis area and severity index (PASI 75 response rate) from baseline at Week 10.ResultsAt Week 10, a total of 68.6% of patients receiving infliximab and none of those receiving placebo, achieved PASI 75 response (p < 0.001). A significant improvement in PASI, PGA, DLQI, and patient's pain assessment was seen from Week 6 through Week 14 in the infliximab group compared with the placebo group. Through Week 66, PASI, PGA, DLQI as well as pain relief were better maintained.ConclusionInfliximab could provide a sustained improvement effect on skin and joint symptoms, and accordingly contributed to a sustained improvement in the QOL of patients with moderate-to-severe plaque psoriasis and psoriatic arthritis. Infliximab was generally well tolerated in most patients. These results corresponded with the results of the trials in the US and the EU.