**3.1.3 Safety**

Alefacept is one of the safest biologic drugs for psoriasis. Clinical trials have demonstrated that it is well tolerated (Gottlieb, 2004; Krueger et al, 2002; Lebwohl et al, 2003; Roberts et al, 2010). The main concern is T lymphocyte depletion so that monitoring of CD4+ T cells is required during treatment and administration should be withheld if the CD4+ T-cell count falls below 250 cells/mL (Biogen Inc., 2003). The most common side effects are pharyngitis, headache, rhinitis, bronchitis and flu (Ellis & Krueger, 2001; Gottlieb et al, 2003; Krueger et al, 2002; Lowe et al, 2003). These infections are not severe, and there is no evidence to date to suggest a predisposition to malignancies associated with alefacept.
