Abstract: 【Abstract】 Objective To evaluate the real-world short-term effectiveness of ixekizumab in the treatment of psoriasis, and to investigate factors influencing the effectiveness. Methods Baseline data and short-term effectiveness evaluation results were retrospectively collected from patients with psoriasis, who received ixekizumab treatment in Department of Dermatology, Xiangya Hospital from November 2019 to September 2021. A descriptive analysis was performed on the baseline characteristics of patients, continuous data were described as median （lower quartile, upper quartile）, and categorical data were described as percentages. Comparisons of disease severity scores before and after the treatment with ixekizumab were performed using Wilcoxon signed-rank test or paired McNemar test. Multivariable logistic regression analysis was conducted to explore factors influencing the effectiveness of 4-week ixekizumab treatment. Results A total of 118 patients with psoriasis were included, including 94 males and 24 females, and their age ［M （Q1, Q3）］ was 43.4 （32.5, 53.0） years; plaque psoriasis （99 cases, 83.9%） and severe psoriasis （72 cases, 68.6%） predominated among the 118 patients, and skin lesions were mainly located on the scalp （59/116, 50.9%）. Among the 49 patients who had received 2-week ixekizumab treatment, 27 （55.1%） achieved a 50% improvement in the psoriasis area and severity index （PASI） score （PASI50）; after 4-week treatment, 44 （89.8%）, 30 （61.2%）, 13 （26.5%） and 10 （20.4%） patients achieved PASI50/75/90/100 respectively, and their PASI scores （2.1 ［1.1, 7.1］）, involved body surface area （3.9% ［0.5%, 14.5%］）, dermatology life quality index scores （1.0 ［0.0, 2.0］） and physician global assessment （PGA） scores （1.0 ［1.0, 3.0］） were significantly lower than the corresponding scores at baseline （12.4 ［8.8, 23.2］, 22.0% ［11.3%, 43.4%］, 6.0 ［3.0, 11.0］, 4.0 ［3.0, 5.0］, respectively; all P < 0.001］. Multivariable logistic regression analysis showed that the baseline body mass index was significantly associated with the PASI75 response rate （OR = 0.814, 95% CI: 0.659 - 0.958, P = 0.029）and the proportion of patients with PGA0/1 （OR = 0.743, 95% CI: 0.562 - 0.917, P = 0.017） after 4-week ixekizumab treatment, and the baseline BSA score was significantly associated with the proportion of patients with PGA0/1 after 4-week ixekizumab treatment（OR = 0.924, 95% CI: 0.870 - 0.968, P = 0.003）. Conclusion The 4-week ixekizumab treatment significantly decreased the severity of psoriasis, and may be more effective in patients with lower disease severity and lower body mass index at baseline.

Key words: Psoriasis, Biological agents, Treatment outcome, Ixekizumab, Body mass index