An international, randomized, double-blind, placebo-controlled phase 3 trial of intramuscular alefacept in patients with chronic plaque psoriasis

Arch Dermatol. 2003 Jun;139(6):719-27. doi: 10.1001/archderm.139.6.719.


Background: Alefacept, human lymphocyte function-associated antigen 3/immunoglobulin 1 fusion protein, binds to CD2 molecules on the surface of activated T cells, selectively targeting memory-effector (CD45RO+) T cells, which comprise more than 75% of T cells in psoriatic plaques.

Objective: To examine the efficacy and tolerability of intramuscular alefacept.

Design: International, randomized, double-blind, placebo-controlled, parallel-group trial.

Patients: A total of 507 patients with chronic plaque psoriasis.

Intervention: Placebo, 10 mg of alefacept, or 15 mg of alefacept administered once weekly for 12 weeks followed by 12 weeks of observation.

Main outcome measure: Psoriasis Area Severity Index (PASI).

Results: Alefacept treatment was associated with dose-related significant improvements in PASI from baseline. Throughout the study, a greater percentage of patients in the 15-mg group than in the placebo group achieved a significant reduction in PASI. Of patients in the 15-mg group who achieved at least 75% PASI reduction 2 weeks after the last dose, 71% maintained at least 50% improvement in PASI throughout the 12-week follow-up. There were no opportunistic infections and no cases of disease rebound.

Conclusion: Intramuscular administration of alefacept was a well-tolerated and effective therapy for chronic plaque psoriasis and thus represents a convenient alternative to intravenous dosing.

Publication types

  • Clinical Trial
  • Clinical Trial, Phase III
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Alefacept
  • Canada
  • Child
  • Child, Preschool
  • Chronic Disease
  • Dose-Response Relationship, Drug
  • Double-Blind Method
  • Europe
  • Female
  • Humans
  • Injections, Intramuscular
  • International Cooperation
  • Male
  • Middle Aged
  • Psoriasis / drug therapy*
  • Psoriasis / pathology
  • Recombinant Fusion Proteins / administration & dosage*
  • Recombinant Fusion Proteins / adverse effects
  • Recombinant Fusion Proteins / therapeutic use*
  • Severity of Illness Index
  • Treatment Outcome
  • United States


  • Recombinant Fusion Proteins
  • Alefacept