Consistency of Infliximab Response across Subgroups of Patients with Psoriasis: Integrated Results from Randomized Clinical Trials

Abstract

Background To assess the consistency of infliximab (Remicade) response among different subgroups of patients with moderate to severe psoriasis, the impact of gender, obesity, age, baseline psoriasis severity, concomitant psoriatic arthritis (PsA), or prior therapies on response to infliximab was studied in an integrated efficacy analysis. Methods Data from three randomized, placebo-controlled clinical trials (SPIRIT, EXPRESS and EXPRESS II) that evaluated the use of infliximab in patients with moderate to severe psoriasis were included in this integrated analysis. Patients received placebo, infliximab 3 mg/kg, or infliximab 5 mg/kg at 0, 2 and 6 wks. The common primary end point at week 10 was the proportion of patients achieving ≥75% improvement in the Psoriasis Area and Severity Index (PASI 75) from baseline. Safety data through week 16 were pooled for analysis. Results Of the 1,462 patients included in this analysis, 70.6% and 79.3% in the infliximab 3 and 5 mg/kg groups, respectively, achieved at least a PASI 75 response at week 10, compared with 2.7% in the placebo group (both p<0.001). The proportions of patients achieving PASI 75 at week 10 were consistent in subgroups defined by baseline demographic characteristics (gender, age, body mass index) and also defined by baseline disease characteristics (PASI severity, body surface area, presence of psoriatic arthritis). Consistent results were also observed regardless of psoriasis therapeutic history. Infliximab treatment was generally well-tolerated by the majority of study participants. Conclusion A consistently high level of clinical response to infliximab was demonstrated across subgroups defined by a variety of baseline demographic and disease characteristics in patients with psoriasis. Infliximab was similarly effective regardless of previous use of phototherapy or major conventional systemic therapies.