Women With Ankylosing Spondylitis Have Lower Anti-TNF Agent Retention Rate Than Men

In treating ankylosing spondylitis (AS), anti—tumor necrosis factor (anti-TNF) drugs produce a response in approximately 60% of patients. For the 40% of patients who do not respond to treatment, previous studies have suggested that patient characteristics, including sex, may play a role.

Reporting findings in the International Journal of Rheumatic Diseases, investigators from the Netherlands sought to compare the long-term drug survival of anti-TNF therapies in men and women treated at a single large center in a retrospective study.

Data for all patients with AS who received etanercept, adalimumab, or infliximab between 2004 and 2014 (n = 122) were included in the analysis. The participants were 48 women (39.3%) and 74 men (60.7%). More patients used adalimumab (59.7%) than etanercept (28.9%) or infliximab (11.3%). After starting treatment, the mean follow-up duration was 5.1 years (range, 0.1-10.6).

Analysis over 10 years found that etanercept had the highest survival rate (85.3% after 3.7 years), followed by adalimumab and infliximab. In total, 22 patients (17.2%) eventually stopped treatment without starting a new therapy, and 32 (26.2%) switched to another anti-TNF agent. Treatment discontinuation was due primarily to inefficacy (in 21 patients; 52.4%) or adverse events (AEs), especially infections.

Women had significantly lower treatment survival than men, at 33.4 months versus 44.9 months (P = .031; 95% CI, 1.1-22). Among patients who switched to another drug, women switched more frequently than men (26.9% vs 16.3%), and with respect to AEs, women had a 26.1% change of developing infections compared with an 18.7% risk for men. Although not statistically significant, women completely stopped anti-TNF therapy more often than men did (20.8% vs 14.9%).

Given the fact that women had shorter treatment periods and also appeared to be more prone to infections, say the authors, it will be important to assess the possible associations of infection rates with sex in order to find strategies that could increase drug survival for women patients with AS who do respond to anti-TNF therapy.

Reference

Rusman T, ten Wolde S, Euser SM, van der Ploeg T, van Hall O, van der Horst-Bruninsma IE. Gender differences in retention rate of tumor necrosis factor alpha inhibitor treatment in ankylosing spondylitis: a retrospective cohort study in daily practice. Int J Rheum Dis. 2018;21(4):836-842. doi: 10.1111/1756-185X.13271.