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.
To examine the efficacy and tolerability of intramuscular alefacept.
A total of 507 patients with chronic plaque psoriasis.
Placebo, 10 mg of alefacept, or 15 mg of alefacept administered once weekly for 12 weeks followed by 12 weeks of observation.
Psoriasis Area Severity Index (PASI).
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.
Intramuscular administration of alefacept was a well-tolerated and effective therapy for chronic plaque psoriasis and thus represents a convenient alternative to intravenous dosing.