Changes in C-reactive protein in patients with moderate-to-severe psoriasis switched to adalimumab therapy after suboptimal response to etanercept, methotrexate or phototherapy

BackgroundPsoriasis treatment can lower levels of the inflammatory biomarker C-reactive protein (CRP). ObjectiveEvaluate CRP changes in patients with chronic plaque psoriasis who switched to adalimumab following suboptimal response to previous therapies. MethodsC-reactive protein was measured at screening and after 16weeks of adalimumab treatment following discontinuation of previous therapies: etanercept (substudy E; n=77), methotrexate (substudy M; n=38) or narrow-band ultraviolet B phototherapy (substudy P; n=27). Associations of CRP with baseline characteristics and efficacy measures were evaluated. ResultsMedian CRP change at the final visit was -0.3mg/L overall and -0.4, -0.3 and -0.3mg/L in substudies E, M and P respectively. Clinical response [Physician Global Assessment (PGA) clear' or minimal'] was associated with greater CRP reductions vs. no response (PGA mild' or worse) overall (-0.4 vs. -0.3mg/L) and in substudies E (-0.4 vs. -0.1mg/L) and M (-0.5 vs. -0.2mg/L), but not P (-0.1 vs. -0.4mg/L). CRP decreases were, respectively, -0.4 and -0.3mg/L in patients with and without a history of psoriatic arthritis and -0.1, -0.3 and -0.6mg/L in normal weight, overweight and obese patients, respectively. CRP decreases after 16weeks correlated positively (=0.004) with percentage change in Psoriasis Area and Severity Index (PASI; P=0.0398) and negatively (=-0.360) with baseline CRP (P<0.0001). ConclusionC-reactive protein levels decreased during adalimumab therapy in patients with psoriasis who experienced suboptimal response to previous therapies. Clinical response was associated with greater CRP reductions overall and in substudies E and M, but not P. CRP reductions correlated with percentage reductions in PASI.