Background: The 12-week, double-blind, placebo-controlled, first-treatment (FT) CLEAR trial period demonstrated the efficacy/safety of efalizumab in moderate-to-severe plaque psoriasis, including refractory or contraindicated patients unsuitable for other systemic treatments. This study assessed the efficacy/safety of open-label extended treatment (up to 24 weeks' continuous treatment) in patients not achieving > or =75% improvement in Psoriasis Area and Severity Index (PASI-75) at week 12 of the FT period. Time to relapse after treatment cessation, and efficacy/safety of 12 weeks' open-label re-treatment in patients achieving PASI-75 at week 12 FT were also assessed.
Patients and methods: Patients with PASI-75 at week 12 FT were observed without treatment until relapse, then re-treated with open-label efalizumab (1.0 mg/kg/week for 12 weeks). Others received open-label extended treatment without intervening observation.
Results: Among efalizumab-treated patients (n = 308) who had < 75% PASI improvement at week 12 FT, extended treatment led to PASI-75 in 26.6%. Among patients with between > or = 50 and < 75% PASI improvement at week 12 FT (n = 118), 47.5% improved to PASI-75 with extended treatment. For patients achieving PASI-75 at week 12 FT (n = 164), median time to relapse was 58 days. Re-treatment after relapse led to mean PASI improvement of 62.3% from study baseline (n = 145). Safety results were consistent with previous studies, with no new safety concerns.
Conclusions: These results demonstrate additional benefit of continuing efalizumab. Re-treatment re-established disease control in patients with PASI-75 who relapsed following treatment cessation. The safety profile remained consistent with that seen at 12 weeks.