Safety of efalizumab in adults with chronic moderate to severe plaque psoriasis: A phase IIIb, randomized, controlled trial

Background To provide safety data for efalizumab, a recombinant humanized monoclonal IgG(1) antibody, in adults with chronic plaque psoriasis. Methods A 12-week, Phase IIIb, randomized, double-blind, parallel-group, placebo-controlled trial. At 58 study sites in the USA and Canada, 686 patients with moderate to severe chronic plaque psoriasis received an initial conditioning dose of efalizumab 0.7 mg/kg subcutaneously (SC) followed by either 11 weekly doses of efalizumab 1 mg/kg SC or matching placebo. Main outcome measures were safety and tolerability outcomes (primary) and efficacy outcomes (secondary). Results During 12 weeks of therapy with efalizumab or placebo, the incidence of clinical adverse events was 82.2% and 72.9%, respectively; the incidence of serious adverse events was 1.8% and 3.4%, respectively; and the incidence of nonserious adverse events leading to withdrawal was 1.8% and 1.7%, respectively. In the efalizumab group, there were no clinically significant changes in vital signs or laboratory parameters and no evidence of end-organ toxicities. A significantly higher proportion of patients receiving efalizumab than those receiving placebo achieved >= 75% improvement in the Psoriasis Area and Severity Index (PASI) (P < 0.001), >= 50% improvement in PASI (P < 0.001), and a static Physician's Global Assessment rating of Minimal or Clear (P < 0.001). The mean improvement in the Psoriasis Symptom Assessment was significantly greater in the efalizumab group (P < 0.001). Conclusions Efalizumab treatment SC for 12 weeks was safe, well tolerated, and effective in patients with moderate to severe chronic plaque psoriasis.