Study of Therapeutic Options for Subjects Discontinuing Efalizumab and Experiencing Disease Recurrence

Inclusion Criteria: * Participation in Genentech study ACD2601g, Genentech study HUPA 600 or Serono study IMP24011. * Inflammatory psoriasis disease recurrence occurring up to 2 months after discontinuation of efalizumab that required immediate therapeutic control in the opinion of the Investigator. Psoriasis had to be rapidly developing, symptomatic and inflammatory in nature. * Written informed consent, given prior to any study-related procedure not part of the subject's normal medical care, with the understanding that the subject could withdraw consent at any time without prejudice to his or her future medical care. * Female subjects had to be neither pregnant nor breast-feeding, and had to lack childbearing potential, as defined by either: * Being post-menopausal or surgically sterile, or * Using an accepted form of contraception. * Confirmation that the subject was not pregnant had to be established by a negative urinary hCG test at SD1. A pregnancy test was not required if the subject was post-menopausal or surgically sterile. * Outpatient status at the time of enrolment. Exclusion Criteria: * Disease recurrence that was part of the natural disease progression, was not inflammatory in nature, and was not related to efalizumab study medication in the previous study.