at the virtual annual congress of the European Academy of Dermatology and Venereology.
He presented highlights of a multicenter translational study, which utilized whole transcriptome analysis of lesional and nonlesional skin from patients with HS and normal controls along with quantitative real-time PCR and immunohistochemistry. The purpose was to further define the molecular taxonomy of this inflammatory disease. And while this objective was achieved, the results also underscored a truism regarding the painful and scarring disease: “HS is characterized by an ever-growing complexity, which translates into multiple potential mechanistic drivers,” observed Dr. da Costa, head of immunology precision medicine at AstraZeneca in Gothenburg, Sweden.
Indeed, the study identified a panel of immune-related drivers in HS that influence innate immunity and cell differentiation in follicular and epidermal keratinocytes. The research by Dr. da Costa and coinvestigators identified a broad array of promising novel therapeutic targets in HS.
“Our findings provide evidence of an inflammatory process coupled with impaired barrier function, altered epidermal cell differentiation, and possibly abnormal microbiome activity which can be seen at the follicular and epidermal keratinocytes and also to a minor degree at the level of the skin glands,” Dr. da Costa said.
There is a huge unmet need for new therapies for HS, since at present adalimumab (Humira) is the only approved medication for this debilitating inflammatory disease. Some good news that emerged from this translational study is that some of the novel molecular mediators implicated in HS are targeted by multiple Food and Drug Administration–approved therapies that have other indications. From a drug development standpoint, repurposing a commercially available drug for a novel indication is a much more efficient and less costly endeavor than is necessary to establish the safety and efficacy of an unproven new agent.
The translational work demonstrated that the proteins calgranulin-A and -B and serpin-B4 were strongly expressed in the hair root sheaths of patients with HS. Connexin-32 and koebnerisin were present in stratum granulosum, matrix metallopeptidase-9 was strongly expressed in resident monocytes, small prolin-rich protein 3 in apocrine sweat glands and ducts as well as in sebaceous glands and ducts, and transcobalamin-1 was prominent in stratum spinosum.
Of the 19 key molecular mediators of HS identified in the study, FDA-approved agents are already available that target 12 of them. For example, apremilast (Otezla) targets interferon-gamma and tumor necrosis factor–alpha. Gentamicin targets growth arrest-specific 6 (GAS6) and interleukin-17 (IL-17). Secukinumab (Cosentyx) and ixekizumab (Taltz) target IL-17A, and brodalumab (Siliq) more broadly targets IL-17A as well as all the other IL-17 receptors. Thalidomide targets hepatocyte growth factor (HGF) and TNF-alpha. Spironolactone targets androgen receptor (AR) and TNF-alpha. Colchicine targets tubulin. Anakinra (Kineret) homes in on the IL-1 receptor. And prednisone targets NFxB.
Other key molecular mediators of HS, which are targeted by commercially available drugs, include epidermal growth factor (EGF), macrophage colony-stimulating factor (MCSF), epiregulin (EREG), fibroblast growth factor 1 (FGF1), FGF2, insulin-like growth factor 2 (IGF2), and IL-6, according to Dr. da Costa.
In addition, clinical trials are underway in HS involving totally investigational agents, including several Janus kinase inhibitors and tyrosine kinase 2 inhibitors.
The work described by Dr. da Costa had multiple funding sources, including the European Hidradenitis Suppurativa Foundation, the University of Copenhagen, the Icahn School of Medicine at Mount Sinai, AstraZeneca, and the German Federal Ministry of Education and Research. Dr. da Costa is an employee of AstraZeneca, Gothenburg, Sweden.