**7.2 T-cell modulators**

In 2003, alefacept and efalizumab were the first biological agents to be approved by the Food and Drug Administration (FDA) for the treatment of psoriasis (Pathirana et al., 2009). In the European Union, only efalizumab was approved for the psoriasis therapy (Pathirana et al., 2009). In 2009, efalizumab was withdrawn from the market in Europe and the United States (EMEA, 2009; Food and Drug Administration [FDA], 2009).
