Targeted treatments for hidradenitis suppurativa: a review of the current literature and ongoing clinical trials

Purpose: Targeted, immune-modulating drugs are at the forefront of therapy for HS, and a comprehensive clinical trial registry is needed to facilitate data pooling and clinical efficacy comparison.Materials and methods: A systematic review of the ClinicalTrials.gov database was searched for planned, in-progress, completed, or terminated trials investigating the effect of targeted biologic therapies for hidradenitis suppurativa (HS). When results of RCTs were not available, case reports or series were included.Results: Inflammatory mediators that are targeted by biologic agents include tumor necrosis factor-alpha (TNF-), interleukin-1 (IL-1), IL-17, IL-12, IL-23, phosphodiesterase 4 (PDE4), lymphocyte function-associated antigen 1 (LFA-1), and complement component 5a (C5a). Clinical efficacy was measured by reduction in Sartorius score, Hidradenitis Suppurativa Clinical Response (HiSCR), Dermatology Life Quality Index (DLQI), or pain Visual Analog Scale (VAS). TNF inhibitors (adalimumab, etanercept, and infliximab), IL-1 receptor antagonist (Anakinra), IL-17A inhibitor (secukinumab), IL-12/23 inhibitor (ustekinumab), and PDE4 inhibitor (apremilast) show promise due to statistically significant improvements in disease severity.Conclusions: Currently, adalimumab is the only FDA-approved biologic available for the treatment of HS. However, results from trials of other biologic agents targeting downstream mediators are promising. Large-scale, randomized, placebo-controlled trials in patients with skin of color, as well as weight-based dosing trials, are needed.