• The proportion of subjects who acheive a score of clear (0) or almost clear (1) on the PGA og LMB at weeks 4 and 6. [ Time Frame: Four and six weeks. ] [ Designated as safety issue: No ]
• The incidence of adverse events caused by calcipotriene/betamethasone (Taclonex) at weeks 2, 4 and 6. [ Time Frame: Weeks 2, 4 and 6 ] [ Designated as safety issue: Yes ]

The purpose of this study is to determine if calcipotriene/bethamethasone can safely and effectively manage the occurence of LMB (mild localized breakthrough) in patients recieving efalizumab (Raptiva) for moderate to severe plaque psoriasis.

It is hypothesized that calcipotriene/betamethasone (Taclonex) could be used to manage LMB and thus allow patients to continue efalizumab without interruption.

LMB (localized mild breakthrough)is one of two psoriasis adverse events commonly seen in efalizumab treated patients. It is generally papular in nature and does not involve existing lesions. Clinical experience suggests that LMB may not have a clinical impact in patients responding to efalizumab and therefore may be treated without interrupting efalizumab therapy. To relieve discomfort topical therapy may be indicated until the symptoms are resolved.

This is a single arm, open label study. Fifteen patients who are receiving efalizumab before entrance into this study and who develop LMB wil be enrolled. Topical calcipotriene/betamethasone (Taclonex) will be applied to the areas (except face, axillae or groin) once a day for two weeks. The PI may choose to continue two more weeks if needed for a total of four weeks of therapy. All patients will continue with efalizumab without dose modification for the duration of the study. Patients will return for follow up visits at weeks 2, 4 and 6. Topical desonide may be used for LMB involvement of the face, groin or axillae.

• Carey W, Glazer S, Gottlieb AB, Lebwohl M, Leonardi C, Menter A, Papp K, Rundle AC, Toth D. Relapse, rebound, and psoriasis adverse events: an advisory group report. J Am Acad Dermatol. 2006 Apr;54(4 Suppl 1):S171-81. Review.
• Menter A, Leonardi CL, Sterry W, Bos JD, Papp KA. Long-term management of plaque psoriasis with continuous efalizumab therapy. J Am Acad Dermatol. 2006 Apr;54(4 Suppl 1):S182-8. Review. No abstract available.
• Werther WA, Gonzalez TN, O'Connor SJ, McCabe S, Chan B, Hotaling T, Champe M, Fox JA, Jardieu PM, Berman PW, Presta LG. Humanization of an anti-lymphocyte function-associated antigen (LFA)-1 monoclonal antibody and reengineering of the humanized antibody for binding to rhesus LFA-1. J Immunol. 1996 Dec 1;157(11):4986-95.

Inclusion Criteria:

• Ability to provide written, informed consent and comply with study assessments for the full duration of the study.
• Age 18 years or older.
• Moderate to severe plaque psoriasis being treated with efalizumab.
• Develop LMB during efalizumab treatment.
• PGA of LMB at least mild (2) excluding face, axillae and groin.

Exclusion Criteria:

• Patients with known hypersensitivity to efalizumab, calcipotriene/betamethasone or any of its components.
• Pregnant or lactating women.
• Known or suspected disorders of calcium metabolism.
• Erythrodermic, exfoliative and/or pustular psoriasis.
• Concomitant use of topical thaerapy, phototherapy or immunosuppressive agents.
• LMB (in areas other than face, axillae or groin) constitutes more than 30% of total body surface area.
• Patients with generalized inflammatory flare which is defined as widespread worsening of psoriasis characterized by erythematous and and edematous lesions within exisiting plaques.
• Any other condition the investigator believes would pose a significant hazard to the subject if the investigational therapy were initiated.