Fifteen RCTs were included in the meta-analysis (6,973 patients; appendix 2). A further eight trials appear to have been included in the quality of life analysis (table 5). The follow-up time used in the meta-analyses was after 10 to 12 weeks of treatment.
Psoriasis severity outcomes: Compared with placebo, statistically significant benefits were observed in attaining a 75% reduction from baseline in the Psoriasis Area and Severity Index (PASI 75) with biological therapy using infliximab (RR 25.48, 95% CI 14.04 to 46.23; four RCTs n=1,072 patients), etanercept 50mg/kg administered subcutaneously twice weekly (RR 11.92, 95% CI 8.17 to 17.39, three RCTs; n=1,334 patients), etanercept 25mg/kg administered subcutaneously twice weekly (RR 10.68, 95% CI 6.15 to 18.57; three RCT), efalizumab 1 to 2mg/week (RR 7.47, 95% CI 5.20 to 10.73; four RCTs), and alefacept administered weekly at a range of doses (RR 3.37, 95% CI 2.18 to 5.23; three RCTs). Findings were similar for the proportions of patients achieving PASI 50 and PASI 90.
The results from the hierarchical model indicated that the use of infliximab significantly increased the likelihood of patients attaining a PASI 50, PASI 75 or a PASI 90 response at 10-12 weeks of follow-up compared to both dose of etanercept, efalizumab, and alefacept.
Statistically significant heterogeneity was observed only for the comparison of infliximab with placebo for the proportions of patients attaining PASI 50 (Q=4.77, p=0.029) and PASI 75 (Q=8.742, p=0.033).
Quality of life outomes: Compared with placebo, statistically significant benefits were achieved in health-related quality of life measured by the Dermatology Life Quality Index with biological therapy using infliximab 5mg/kg (pooled MD 8.52, 95% CI 4.95 to 12.08;, two RCTs), etanercept 50mg twice weekly (pooled MD 6.07, 95% CI 3.99 to 8.16; three RCTs), etanercept 25mg twice weekly (pooled MD 5.66, 95% CI 3.27 to 8.04; two RCTs), efalizumab (pooled MD 3.54, 95% CI 2.05 to 5.02; two RCTs), and alefacept (pooled MD 1.65, 95% CI 1.23 to 2.07, six trials).
Safety: There were no differences in the proportions of patients who discontinued treatment between the biological response modulator treatment groups and the patients who received placebo treatment.