Clinical experience acquired with the efalizumab (Raptiva®) (CLEAR) trial in patients with moderate-to-severe plaque psoriasis:: results from a phase III international randomized, placebo-controlled trial

Background Efalizumab (anti-CD11a), a humanized monoclonal antibody, blocks multiple T-cell-dependent functions implicated in the pathogenesis of psoriasis, including T-cell activation, migration to the skin, reactivation in psoriatic skin and interactions with keratinocytes. Objectives This multinational, randomized, double-blind, placebo-controlled, parallel-group trial was designed to evaluate the safety and efficacy of subcutaneous efalizumab 1.0 mg kg(-1) once weekly for 12 weeks compared with placebo in a population that included high-need patients, defined as those for whom at least two systemic therapies were unsuitable because of lack of efficacy, intolerance or contraindication. Patients/methods Patients with moderate-to-severe plaque psoriasis [involvement of >= 10% of total body surface area and Psoriasis Area and Severity Index (PASI) >= 12.0 at screening] were randomized in a 2 : 1 ratio to receive efalizumab or placebo. The primary efficacy endpoint was the proportion of patients achieving >= 75% PASI improvement (PASI-75 response) at week 12 in the intention-to-treat population; secondary endpoints included changes in PASI, static Physician's Global Assessment, Physician's Global Assessment of change from baseline and percentage of body surface area affected. Results We enrolled 793 patients (529 received efalizumab and 264 placebo), including 526 high-need patients (342 received efalizumab and 184 placebo). Week 12 PASI-75 rates were 29.5% for efalizumab compared with 2.7% for placebo among high-need patients (P < 0.0001) and 31.4% for efalizumab compared with 4.2% for placebo in the full study population (P < 0.0001). Results for all secondary efficacy endpoints showed superiority of efalizumab over placebo in both the high-need and the full populations. Efalizumab demonstrated a favourable safety profile, without evidence of systemic toxicity, in both the high-need group and the overall study population. Conclusion The efficacy and safety of efalizumab therapy were comparable between high-need patients and the more general moderate-to-severe psoriasis patient population. In view of its demonstrated efficacy and safety profile, efalizumab represents a valuable option for the treatment of adult patients with moderate-to-severe plaque psoriasis, including high-need patients.