POS0077 SEX DIFFERENCES IN EFFECTIVENESS OF FIRST-LINE TUMOR NECROSIS FACTOR INHIBITORS IN PSORIATIC ARTHRITIS; RESULTS FROM THIRTEEN COUNTRIES IN THE EuroSpA RESEARCH COLLABORATION NETWORK

Abstract

BackgroundEvidence demonstrates sex differences in disease presentation, physical function, treatment response and drug retention in patients with psoriatic arthritis (PsA). Data from observational cohort studies indicate female sex is associated with reduced effectiveness of tumor necrosis factor inhibitors (TNFis)1,2. Although, conflicting results are also reported3,4. We sought to validate prior studies using data from a large multinational cohort based on real-life clinical practice.ObjectivesTo investigate sex differences in treatment response and drug retention rates in clinical practice among patients with PsA, treated with their first TNFi.MethodsData from biologic-naïve PsA patients initiating a TNFi in the EuroSpA registries were pooled. In the primary analysis, propensity-score weighting was applied to assess the causal effect of sex on low disease activity (LDA) according to DAS28-CRP at 6 months. A generalized linear regression model was used to estimate the causal risk difference (RD) and relative risk (RR) of sex on LDA. Possible covariates influencing the outcome were determined a priori and selected based on availability in the database (<20% missing). The final covariates included were country, age, conventional synthetic disease-modifying antirheumatic drug use at baseline and TNFi start year. In the secondary analysis, drug retention was assessed over 24 months of follow-up by Kaplan-Meier curves and log-rank test.ResultsIn total, 7,679 PsA patients with available data on DAS28-CRP at 6 months were assessed for treatment response. Baseline characteristics are shown in the Table 1. In the adjusted analysis, the probability for females to have LDA was 17% (RR, 0.83; 95% confidence interval [CI], 0.81 to 0.85) lower compared to males and the difference in probability for having LDA was 13 percentage points (RD, 0.13; 95% CI, 0.11 to 0.15). The survival analysis included 18,599 PsA patients with available data on retention rates. The TNFi 6/12/24-month retention rates were significantly lower in females (81%/68%/56%) compared to males (89%/80%/69%), see Figure 1.Table 1.Baseline characteristics of all biologic-naïve PsA patients treated with their first TNFi and available DAS28-CRP at 6 month, data pooled across all countriesFemaleMaleMean (SD), median [IQR] or percentagesMean (SD), median [IQR] or percentagesAge (years)49.7 (12.5)47.8 (11.9)Disease duration (years)4.0 [1.0, 10.0]4.0 [1.0, 10.0]TNFi start year 1999-200929%29% 2010-201326%27% 2014-201625%24% 2017-202020%20%Concomittant csDMARD75%77%DAS28-CRP4.4 (1.2)4.2 (1.2)DAPSA2832 (16)29 (16)CRP (mg/L)7.0 [3.0, 17.0]8.0 [3.3, 19.0]SJC (0-28)3.0 [1.0, 6.0]3.0 [1.0, 6.0]TJC (0-28)6.0 [2.0, 10.0]4.0 [2.0, 9.0]VAS pain, mm61 (23)55 (23)VAS fatigue, mm62 (26)53 (27)Data are as observed, mean (SD), median [IQR] or percentage. TNFi, tumor necrosis factor inhibitor; csDMARD, Conventional synthetic disease-modifying antirheumatic drugs; DAS28-CRP, Disease Activity Score 28-joint count C reactive protein; DAPSA28, Disease Activity in PsA 28; CRP, C-reactive protein; SJC, swollen joint count; TJC, tender joint count.ConclusionTreatment efficacy and retention rates are lower among female patients with PsA initiating their first TNFi. Females presented with higher 28-tender joint count and higher scores on patient reported outcomes at baseline, reflecting differences in disease expression. Recognizing these sex differences is of relevance for customized patient care and may improve patient education.