Title: Efalizumab
CAS Registry Number: 214745-43-4
CAS Name: Anti-(human CD11a (antigen)) immunoglobulin G1 (human-mouse monoclonal hu1124 g1-chain) disulfide with human-mouse monoclonal hu1124 light chain, dimer
Additional Names: hu1124
Trademarks: Raptiva (Genentech); Xanelim (Genentech)
Literature References: Humanized monoclonal IgG1 antibody directed against the CD11a subunit of lymphocyte function-associated antigen-1 (LFA-1). Inhibits lymphocyte activation, migration and adhesion to endothelial cells. Prepn: P. M. Jardieu, L. G. Presta, WO 9823761; eidem, US 6037454 (1998, 2000 both to Genentech); W. A. Werther et al., J. Immunol. 157, 4986 (1996). Clinical pharmacokinetics: R. J. Bauer et al., J. Pharmacokinet. Biopharm. 27, 397 (1999). Clinical study in psoriasis: M. Lebwohl et al., N. Engl. J. Med. 349, 2004 (2003). Review of pharmacology and therapeutic potential: R. L. Dedrick et al., Transplant Immunol. 9, 181-186 (2002); J. C. Cather et al., Expert Opin. Biol. Ther. 3, 361-370 (2003); of use in chronic psoriasis: J. C. Cather, A. Menter, Expert Opin. Biol. Ther. 5, 393-403 (2005).
Therap-Cat: Antipsoriatic; immunosuppressant.
Keywords: Antipsoriatic.
Efaproxiral Efavirenz Eflornithine Efloxate Efonidipine

Efalizumab ?
Monoclonal antibody
Type Whole antibody
Source Humanized (from mouse)
Target CD11a
Clinical data
Trade names Raptiva
AHFS/Drugs.com monograph
Legal status  ?
Routes subcutaneous injection
CAS number 214745-43-4 YesY
ATC code L04AA21
DrugBank DB00095
Chemical data
Formula  ?
Physical data
Melt. point 66 °C (151 °F)
 N (what is this?)  (verify)

Efalizumab (trade name Raptiva, Genentech, Merck Serono) is a formerly available medication designed to treat autoimmune diseases, originally marketed to treat psoriasis. As implied by the suffix -zumab, it is a recombinant humanized monoclonal antibody administered once weekly by subcutaneous injection. Efalizumab binds to the CD11a subunit of lymphocyte function-associated antigen 1 and acts as an immunosuppressant by inhibiting lymphocyte activation and cell migration out of blood vessels into tissues. Efalizumab was associated with fatal brain infections and was withdrawn from the market in 2009.[1]

Known side effects include bacterial sepsis, viral meningitis, invasive fungal disease and progressive multifocal leukoencephalopathy (PML), a brain infection caused by reactivation of latent JC virus infection.[2][3] Four cases of PML were reported in plaque psoriasis patients, an incidence of approximately one in 500 treated patients.[1]

Due to the risk of PML, the European Medicines Agency and the FDA recommended suspension from the market in the European Union and the United States, respectively.[4] In April 2009, Genentech Inc. announced a phased voluntary withdrawal of Raptiva from the U.S. market.[1][5]