Response to adalimumab in Caucasian and Asian patients with hidradenitis suppurativa: A retrospective cohort study of an Australian cohort stratified by patient-reported ethnicity.

Background/objectives: Caucasian and Asian patients with hidradenitis suppurativa demonstrate significant differences with regard to age, gender and body mass index. Demographic characteristics are known to influence the efficacy and drug survival of hidradenitis suppurativa therapeutics including biologic therapies. What remains unknown is the impact of ethnicity upon the efficacy of therapeutics once demographic and disease characteristics have been taken into account. This is an important question given the expansion of biologic therapies for HS into the global patient community.

Methods: We assessed 170 patients from a single HS specialist centre in Australia stratified by patient-identified ethnicity including those identifying as either Caucasian or Asian.

Results: Asian patients demonstrated lower BMI, higher rates of smoking and greater odds of Hurley stage 3 disease with tunnels than Caucasian patients in line with the reported literature. There was no significant difference between percentage of individuals achieving HiSCR50 or IHS4-55 at Week 16. Significant differences were seen in median time to secondary loss of response, and Kaplan-Meier curve analysis showed a significant difference between curves when stratified by patient-reported ethnicity. Cox regression analysis demonstrated after accounting for age, gender, BMI, smoking and Hurley stage, the significance of ethnicity in influencing time to secondary loss of response disappears.

Conclusions: Caucasian or Asian ethnicity does not influence response to adalimumab treatment on patients with hidradenitis suppurativa.