P433 Sex-based differences in response to tumor necrosis factor inhibitor induction therapy for ulcerative colitis: a pooled analysis of individual patient-level clinical trials data

Abstract

Abstract Background There are increasing data on sex-based differences in IBD epidemiology, phenotype and outcomes. The purpose of this study was to characterize sex-based differences in response to tumor necrosis factor inhibitor (TNFi) therapies in patients with ulcerative colitis (UC). Methods We conducted a pooled analysis of individual-level data from randomized clinical trials (RCTs) on induction therapy with infliximab and golimumab, accessed through the Yale University Open Data Access platform. We analyzed patients in the treatment and placebo arms separately. Using multivariable logistic regression modeling, we compared the primary outcome of clinical remission, and secondary outcomes of clinical response and mucosal healing, according to clinical trial definitions, between male and female patients with UC at week 6 (golimumab) or week 8 (infliximab) of induction therapy. Effect estimates were expressed as adjusted odds ratios (aOR) and 95% confidence intervals (CI). Results We included 1639 patients (696, 42.5% were women, Table) from two trials using infliximab (ACT-1 and 2) and one trial using golimumab (PURSUIT). Male patients were older than female patients in the treatment arm of the overall cohort [mean age (standard deviation) 31.31 (16.53) years and 29.34 (15.19) years, respectively). All other baseline characteristics, such as sex, race, Mayo score at screening, and concomitant systemic corticosteroid and immunomodulator use were comparable. Compared to female patients, male patients were significantly less likely to achieve clinical remission in both treatment and placebo arms (aOR 0.55, 95% CI 0.31, 0.97 and 0.34, 95% CI 0.15, 0.82, respectively, Figure). Compared to female patients, male patients were significantly less likely to achieve mucosal healing and clinical response in the treatment arm (aOR 0.47, 95% CI 0.27, 0.83 and 0.51, 95% CI 0.29, 0.90, respectively), but there was no significant difference in these secondary outcomes by sex in the placebo arm. Conclusion Based on this analysis of pooled data from RCTs, we demonstrate that clinical remission, response and mucosal healing with TNFi induction therapies are less likely in male patients compared to female patients with UC. Clinical remission is also less likely in male patients on placebo. These finding may lead to further research on sex-based differences in treatment outcomes, including mechanistic studies.