Abstract: 【Abstract】 Objective To retrospectively analyze the clinical efficacy and safety of biological agents in the treatment of psoriasis in the elderly. Methods A retrospective study was conducted. A total of 124 patients aged ≥ 65 years with moderate-to-severe psoriasis （psoriasis area and severity index ［PASI］ score ≥ 3 points or body surface area ［BSA］ ≥ 3%）, who were treated with biological agents at the Department of Dermatology and Venereology, People's Hospital of Xinjiang Uygur Autonomous Region, from June 2020 to December 2023, were collected. PASI, BSA, and dermatology life quality index （DLQI） scores were recorded at weeks 0 （pre-treatment）, 4, 12, and 24 after the beginning of treatment to evaluate the efficacy. The proportions of patients achieving ≥ 75% and 90% improvements in PASI scores （PASI75 and PASI90, respectively） were calculated, and adverse reactions were recorded. Data were processed using SPSS 29.0 and GraphPad Prism 10.0 software. Normally distributed continuous variables were presented as mean ± standard deviation, while non-normally distributed continuous variables were presented as median with upper and lower quartiles （Q1, Q3）. Wilcoxon signed-rank test was used for comparisons of non-normally distributed data between groups, and chi-square test and Fisher's exact test were used for comparing categorical data. Results Among the 124 patients, there were 72 males （58.1%） and 52 females （41.9%）, and their ages ranged from 65 to 87 years. Treatment regimens included secukinumab for 86 patients （69.4%）, ustekinumab for 15 （12.1%）, ixekizumab for 14 （11.3%）, guselkumab for 5 （4.0%）, and adalimumab for 4 patients （3.2%）. The pre-treatment PASI, BSA, and DLQI scores ［M （Q1 , Q3）］ were 12.2 （7.8, 19.6） points, 16.0% （10.2%, 25.0%）, and 16 （11, 20） points respectively, which significantly decreased to 0.8 （0, 1.2） points, 1.0% （0, 2.0%）, and 0 （0, 3） points respectively at week 24 after the start of treatment （Z = 9.66, 9.66, 9.63, respectively, all P < 0.01）. The proportions of patients achieving PASI75 at weeks 4, 12, and 24 were 42.7%（53/124）, 80.6%（100/124）, and 93.5%（116/124） respectively, and those achieving PASI90 were 13.7%（17/124）, 48.4%（60/124）, and 85.5%（106/124） respectively. There were no significant differences in the proportions of patients achieving PASI75 and PASI90 between the subgroups with and without comorbidities, as well as between the early-onset psoriasis subgroup and late-onset psoriasis subgroup at weeks 4, 12, and 24 （all P > 0.05）. Among the 124 patients, 42 were followed up for over 2 years, and the proportions of patients achieving PASI75 and PASI90 after 2 years of treatment were 71.4% （30 cases） and 54.8% （23 cases）, respectively. Adverse reactions occurred in 13 patients, including upper respiratory infections in 4 patients （3.2%）, elevated aminotransferase levels in 3 patients （2.4%）, eczematoid dermatitis in 2 patients （1.6%）, pruritus in 2 patients （1.6%）, nodular prurigo in 1 patient （0.1%）, and vitiligo in 1 patient （0.1%）. Conclusion Biological agents showed rapid and marked efficacy in the treatment of moderate-to-severe psoriasis in the elderly, with few and mild adverse reactions, suggesting high safety and overall marked efficacy.

Key words: Psoriasis, Aged, Antibodies, monoclonal, Treatment outcome, Drug-related side effects and adverse reactions, Biological agents