Additional therapies for hidradenitis suppurativa under investigation
The approval of the biologic agent adalimumab for the treatment of moderate-to severe hidradenitis suppurativa (HS), has been encouraging for patients and is likely to increase the potential of surgical treatment having an adjunctive role in the overall therapeutic picture, say Canadian dermatologists.
HS is a chronic condition that tends to affect individuals when they are in the prime of life, generally after puberty and before the age of 40, and is thought to start with the hair follicle. The follicle occludes, dilates, and then ruptures. The condition is characterized by nodules and cysts that, even with surgical treatment, tend to recur. Prior to the approval of adalimumab, HS has typically been treated with a variety of therapies in an off-label fashion.
In terms of epidemiology, HS is a condition that is much more common in women than in men, with a female-male ratio of 3 to 1. The prevalence figures for HS vary but, in Canada, it is estimated that anywhere from 350,0000 to one million Canadians have HS.
Categorizing HS based on severity of disease permits matching the appropriate treatment to a given patient, and clinicians usually rely on the Hurley Staging System to stratify patients based on severity, with Stage I indicating more mild disease and Stage III indicating more severe disease.
There is no single gene that is linked to the development of HS, but HS has been noted to run in families. Mutations in certain genes have been identified as impairing Notch signalling in hair follicles (Br J Dermatol 2017; Mar. 9).
Inflammation plays a significant role in HS, as does the body’s immune system. These two factors support the use of a therapy such as adalimumab. Two randomized clinical trials, PIONEER I and PIONEER II, have found the use of adalimumab elevated the likelihood of a clinically significant response after 12 weeks of therapy, with a response defined by at Medical Director of the Skin Centre for Dermatology in Peterborough, Ont.
“Getting our patients optimized in terms of their disease [through treatment with adalimumab] will make them better surgical candidates,” said Dr. Gooderham. “Surgeons will be more willing to operate on them.”
Comorbidities are not uncommon in patients with HS. Patients with HS can be overweight and often smoke. Other comorbidities include metabolic syndrome, Crohn’s disease, arthritis, and spondyloarthropathy.
“Many of these patients present with so many open wounds. Surgery can be made less complex [with adalimumab treatment].”
Traditional therapies provide some benefit, but medications such as antibiotics are not appropriate for the management of a chronic condition like HS, said Dr. Lynde.
“Many of the treatments we had did not work very well,” he said. “Oral antibiotics can be somewhat effective, but patients have to be on them for the long term.”
HS typically affects the intertriginous areas of the skin such as the axillae, inguinal, gluteal, and submammary zones. As a consequence, the condition typically produces an adverse impact on sexual quality of life and quality of life overall. “Many patients have depression and anxiety,” noted Dr. Lynde.
Intimate partner violence associated
New Canadian research involving 128 patients with HS and 114 patients with acne found that patients with HS were significantly more likely to experience intimate partner violence than patients who have acne, and that healthcare providers should be aware of this association when they interact with HS patients (J Cutan Med Surg 2017 May 1; 1203475417708167).
Crohn’s disease can present with HS. When a patient has a condition like Crohn’s disease and HS, they can be prescribed a biologic that will address both disease processes, explained Mark Kirchhof, MD, PhD, an assistant professor of dermatology at Queen’s University and dermatologist at Hotel Dieu Hospital in Kingston and Kingston Health Sciences Center in Kingston, Ont.
“We often have to dose optimize for both diseases,” said Dr. Kirchhof, noting increasing the dosage of a biologic ensures the diseases are controlled.
One of the frustrating experiences for patients is that many primary healthcare providers are ill-equipped to make a diagnosis of HS.
A Canadian, multi-centre, crosssectional retrospective investigation found more than 40% of HS patients failed to receive a diagnosis in the first five years after initial presentation of
their condition and more than half of patients (56%) received their diagnosis from a dermatologist.
A 2013 survey involving more than 500 HS patients found delay in diagnosis to be a global problem, owing to factors like patients delaying their consultation with a primary care provider and that primary care provider not being able to make the correct diagnosis. The survey found a diagnostic delay of seven years for patients with HS (Br J Dermatol 2015 Dec; 173(6):1546–1549).
Milder forms of HS that do not require biologic treatment can be treated with anti-androgens such as finasteride or dutasteride, noted Dr. Gooderham. “I will also consider spironolactone,” she said.
Several pathways have been identified as propelling the inflammation associated with the condition including TNF-alpha, IL-1beta, IL-17, and IL23, creating potential therapeutic targets for HS. There are proposals to investigate the biologics CJM112 and MABp1 for patients who prove refractory to adalimumab therapy (J Allergy Clin Immunol 2017 May; 139(5):1423– 1430).
Patient education essential
Patient education and engagement is instrumental to achieving effective control of a condition like HS. With the objective of optimizing patient outcomes in mind, the Canadian Hidradenitis Suppurativa Foundation (CHSF) is publishing an electronic patient guide to assist patients with HS on their patient journey.
“This e-guide informs patients about the possible causes of HS, the need for them to track their HS flares, the need to detect triggers of their HS flares, treatment choices available to them, and the evidence for those treatments,” said Dr. Afsaneh Alavi, a Toronto dermatologist, assistant professor at the University of Toronto, immediate past-president of the CHSF, and a co-author of the guide.
“The e-book also provides resources for patients and aims to raise awareness about the disease in an effort to help patients cope with their disease. It is important to keep in mind HS can take a physical, psychological, and an emotional toll on patients.”
Increased education about HS for both patients and healthcare providers contributes to potentially accelerating diagnosis and identifying the disease when it is in an early stage, according to Dr. Alavi.
Non-proprietary and brand name of therapy: adalimumab (Humira, AbbVie).
Originally published in The Chronicle of Skin & Allergy (June 2017; 23(4):page 1,24)