Abstract
BACKGROUND: Adalimumab is a central treatment for moderate-to-severe hidradenitis suppurativa (HS). However, half of patients treated with adalimumab for HS do not achieve a clinically significant response. Data on non-immunological factors correlating clinical response and adalimumab blood concentration are scarce. OBJECTIVES: To determine whether increasing adalimumab dose to 80 mg weekly can improve the clinical outcome of patients unresponsive to adalimumab 40 mg weekly. To identify parameters influencing disease activity and those modifying serum adalimumab concentration. METHODS: This is a retrospective case series from a tertiary dermatology clinic, comprising 40 patients with moderate-to-severe HS with suboptimal response to the FDA-approved dose of adalimumab. All patients had a measurement of blood adalimumab concentration. Depending on their dosage, some patients had their adalimumab dose increased to 80 mg weekly while others stayed at 40 mg dose weekly. Chi-squared and ANOVA tests were used for data analysis. RESULTS: 43.8% of patients who increased to a weekly dose of 80 mg clinically improved at their follow-up, compared with 33.3% of those who stayed at a weekly dose of 40 mg. The dose increase led to a statistically significant increase in serum concentration of adalimumab (P < .001). Higher serum adalimumab concentration is associated with lower disease activity (P = .043). Normal-weight patients had significantly higher concentrations than overweight patients (P = .011). CONCLUSIONS: An increase in the weekly dose of adalimumab led to a nonstatistically significant improvement in clinical response but led to a statistically significant increase in serum concentration.