title: Incidence of infection during efalizumab therapy for psoriasis: analysis of the clinical trial experience.
abstract: BACKGROUND
  Because many therapies for psoriasis disrupt the normal inflammatory cascade and could theoretically impair the body's ability to respond to external pathogens, a possible increase in the incidence of infection is a concern with any new psoriasis therapy that affects the immune system. Efalizumab is a biologic therapy targeted to inhibit T cells. Its efficacy has been shown in clinical trials encompassing >3500 patients with psoriasis.
  
  
  OBJECTIVE
  The aims of this article were to review the incidence of infection observed in efalizumab-treated patients during 12-week, Phase III clinical trials, compare the incidence rate with that in patients receiving placebo, and evaluate the incidence of infection observed in patients with extended (>12-week) efalizumab use.
  
  
  METHODS
  Adverse events (AEs) of infection were tabulated from a pooled data set of 2335 patients enrolled to receive 12 weeks of subcutaneous (SC) efalizumab 1 or 2 mg/kg . wk or placebo in 4 randomized, double-blind, placebo-controlled, Phase III efalizumab clinical studies. The incidence of infection was further evaluated using pooled data from 1115 patients who received up to 24 weeks of efalizumab therapy during 5 clinical trials with treatment extension arms and from 170 patients who received up to 108 weeks (27 months) of continuous therapy in an open-label, Phase III efalizumab trial of 36 months' total duration.
  
  
  RESULTS
  The incidence and severity of AEs of infection during 12 weeks of efalizumab therapy were comparable to those observed in patients receiving placebo (overall, 28.6% vs 26.3%). Infections did not appear to increase with extended therapy of up to 27 months. Serious infections requiring hospitalization occurred in 1.1% of efalizumab-treated patients.
  
  
  CONCLUSIONS
  The present review of the available Phase III clinical trial suggests that efalizumab is not associated with an increased risk for infection in patients receiving initial or long-term (27-month) treatment for moderate to severe chronic plaque psoriasis.
authors.affiliation: Dalhousie University, Halifax, Nova Scotia, Canada. richard.langley@dal.ca
authors.forename: Richard G B
authors.initials: RG
authors.lastname: Langley
authors.forename: Wayne P
authors.initials: WP
authors.lastname: Carey
authors.forename: Elyse S
authors.initials: ES
authors.lastname: Rafal
authors.forename: Stephen K
authors.initials: SK
authors.lastname: Tyring
authors.forename: Ivor
authors.initials: I
authors.lastname: Caro
authors.forename: Xiaolin
authors.initials: X
authors.lastname: Wang
authors.forename: Graham
authors.initials: G
authors.lastname: Wetherill
authors.forename: Kenneth B
authors.initials: KB
authors.lastname: Gordon
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000911:Antibodies, Monoclonal / Q000009:adverse effects / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized; D005260:Female; D006801:Humans; D015994:Incidence; D007239:Infections / Q000453:epidemiology* / Q000209:etiology; D008297:Male; D008875:Middle Aged; D011565:Psoriasis / Q000145:classification / Q000188:drug therapy*; D016032:Randomized Controlled Trials as Topic; D013997:Time Factors
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; C472181:efalizumab