Women with psoriatic arthritis (PsA) presented with more severe disease at baseline and were less likely to achieve favorable outcomes after 12 months of treatment with either ustekinumab (Stelara) or a tumor necrosis factor (TNF) inhibitor, compared with men, according to a post hoc analysis of data from nearly 1,000 individuals.
Although data suggest that the overall prevalence of PsA is similar across genders, recent studies have identified differences in various aspects of PsA between men and women, wrote Arno W.R. Van Kuijk, MD, of Amsterdam Rheumatology and Immunology Center, and colleagues wrote in a study published in Rheumatology.
“Accumulating evidence in multiple rheumatic diseases indicates that gender may influence the likelihood of achieving the desired outcome with treatment,” but studies of differences in treatment response according to gender are limited, they said.
The researchers conducted a post hoc analysis of women and men with PsA who were part of PsABio, a noninterventional European study of patients with PsA. All participants were starting first-, second-, or third-line treatment with ustekinumab or a TNF inhibitor. The primary outcome was response to treatment at 12 months. Disease activity was assessed using the clinical Disease Activity Index for Psoriatic Arthritis (cDAPSA), the Health Assessment Questionnaire–Disability Index (HAQ-DI), and total score on the 12-item Psoriatic Arthritis Impact of Disease (PsAID-12) questionnaire.
Baseline available data for 512 women and 417 men showed the mean duration of disease was similar between genders (6.7 years for females and 6.9 years for males); body mass index was similar, as was the proportion of male and female patients receiving concomitant conventional synthetic disease-modifying antirheumatic drugs (DMARDs). Females scored significantly worse than males on disease activity assessments at baseline with mean cDAPSA scores of 32.3 and 26.8, respectively.
The final analysis of 895 patients with baseline data and a postbaseline assessment included 439 who started ustekinumab (247 females, 192 males), and 456 who started a TNF inhibitor (248 females, 208 males).
At 12 months, females showed smaller degrees of improvement than males; 57.8% and 80.3%, respectively, achieved low disease activity based on cDAPSA scores, while 33.7% and 55.5% of females and males, respectively, achieved minimal disease activity. Measures of disability were higher in females than males, with HAQ-DI scores of 0.85 versus 0.50. PsAID-12 scores also were higher for females, compared with males (3.5 vs. 2.4).
A total of 81.7% of patients were on their initial biologic DMARD after 12 months, but more females than males who were taking ustekinumab or a TNF inhibitor changed or discontinued treatment.
Treatment persistence was significantly lower in females than males (P = .01), and lack of effectiveness was the main reason for discontinuation regardless of gender.
“The analysis of gender subgroup results of the PsABio study has expanded previously published observations that men and women with PsA have different experiences with the disease activity, clinical manifestations, impact on health-related quality of life, response to [biologic] DMARDs, and drug persistence,” the researchers wrote.
The lack of a medication protocol in the PsABio study limited the conclusions that could be drawn from the post hoc analysis, but the results were strengthened by the relatively large and diverse sample size and the inclusion of responses to more than one medication, the researchers noted.
The study was supported by Janssen. Dr. Van Kuijk disclosed serving as a consultant and receiving grant support from Janssen and other companies; several coauthors also disclosed relationships with Janssen.