OBJECTIVES: Ustekinumab(UST) has been shown to improve psoriasis(PsO) and health-related quality of life (HRQoL) in patients(pts) with moderate-to-severe PsO*.This analysis examines the effects of UST on overall skin response and the impact on HRQoL in a subset of PsO pts with psoriatic arthritis(PsA). METHODS: In PHOENIX 1 and 2, pts with moderate-to-severe PsO(n=1996) were randomized to UST45mg or 90mg at wks 0, 4, and q12wk thereafter, or placebo(PBO) at wks 0 and 4 with crossover to UST at wk12.  PsA was identified in pts by medical history. PsO severity was assessed using the Psoriasis Area and Severity Index(PASI) and HRQoL with the Dermatology Life Quality Index (DLQI). RESULTS:  At baseline, 563(28.2%) pts had PsA. The mean PASI was 20.7(SD=8.4) and mean DLQI was 12.6(SD=7.2) indicating significant poor HRQoL. At wk12, UST-treated pts had a significantly greater percent improvement in mean PASI score than PBO-treated pts(45mg: 73.7%, 90mg: 75.3%, PBO: 2.4%; p<0.001).  A significantly greater portion of UST-treated pts achieved PASI75 compared to PBO-treated pts(45mg: 63.0%, 90mg: 61.5%, PBO: 3.6%; p<0.001). UST-treated pts had a significantly greater decrease (improvement) in DLQI score at wk12 than PBO-treated pts(45mg: -9.2 [SD=7.1], 90mg: -9.7[SD=6.6], PBO: -0.01[SD=5.0]; p<0.001). At wk12, 70.2% in the UST 45mg group and 75.0% in the UST 90mg group respectively, experienced ≥5 point improvement in DLQI compared to 15.6 % for the PBO group (p<0.001). UST-treated pts (50.0% and 57.1% in the 45mg and 90mg groups, respectively) had a DLQI score of 0 or 1, indicating no impact of the disease or treatment on HRQoL compared with 1.0% of PBO-treated pts (p<0.001). CONCLUSIONS: UST improved overall skin response and HRQoL in a subset of moderate-to-severe PsO pts with PsA.  This finding will be further evaluated in various ongoing prospective Phase 3 studies.*Lebwohl M, Papp K, Han C, et al. Br J Dermatol 2009;162(1):pg 137-146.