The Clinical Impact of IL-17 Blockade in Hidradenitis Suppurativa Draining Tunnels

In a continuing conversation, Thrasyvoulos Tzellos, MD, PhD, discussed the clinical significance of long-term data from the BE HEARD trial of bimekizumab, with a particular focus on the resolution of draining tunnels in hidradenitis suppurativa (HS) and the implications for future treatment strategies.

Tzellos underscored that draining tunnels represent one of the most important unmet needs in HS management. Although the introduction of tumor necrosis factor (TNF) inhibition—most notably adalimumab—marked a major therapeutic breakthrough and substantially improved patients’ lives, it did not consistently demonstrate a meaningful effect on established draining tunnels. These lesions are closely linked to chronic pain, malodor, persistent suppuration, and profound impairment in quality of life, making them a critical therapeutic target. According to Tzellos, IL-17 inhibition, particularly combined IL-17A and IL-17F blockade, appears to advance treatment beyond what TNF inhibition alone can achieve in this domain.

Data from the BE HEARD program demonstrate clear and consistent effects on draining tunnels across multiple outcome measures. These include reductions in the absolute number of draining tunnels, an increase in the proportion of patients achieving complete resolution, and marked improvements in composite disease severity scores such as the International HS Severity Score System (IHS4). Notably, a substantial number of patients achieved inactive disease or non–draining tunnel status, outcomes that have historically been difficult to reach in HS.

Importantly, Tzellos highlighted that improvements in quality of life were observed regardless of baseline tunnel burden. Patients with only 1 or 2 draining tunnels experienced meaningful benefit, as did those with more extensive disease involving 5 or more tunnels. This suggests that IL-17 inhibition can positively influence patient-reported outcomes across a wide spectrum of disease severity, reinforcing its clinical relevance.

Looking ahead, Tzellos anticipates that these long-term data will influence treatment guidelines and everyday clinical decision-making in Europe and globally. With multiple biologic options now available, he argues that the presence of draining tunnels should prompt clinicians to preferentially consider IL-17–targeted therapies rather than TNF inhibition alone. He noted that combined IL-17A/F inhibition appears to offer a higher and more durable effect on tunnels, supported by reassuring long-term safety data. Although mucocutaneous Candida infections remain a known risk, he emphasized that appropriate patient education and management strategies can mitigate this concern.