Biologic Therapy Shows Promise for Tough Acne

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A notoriously difficult condition to treat due to its chronic and severe nature, acne conglobata (AC) often presents quickly, primarily affecting the face, back, and chest. AC can severely impact patients’ quality of life and mental health due to both its aggression and visibility, leading researchers to take a closer look at its treatment modalities.¹ Traditionally, the condition is treated using isotretinoin and systemic corticosteroids, with successful cases of AC treated with tumor necrosis factor–α inhibitors also reported.^2,3

Researchers Madanchi et al recently published several case studies outlining a promising off-label treatment for the condition: the biologic agent bimekizumab, a dual interleukin-17A and interleukin-17F inhibitor.⁴ These cases demonstrate not only the drug’s effectiveness in lesion reduction but also its potential to bypass the emotional and physical toll often associated with traditional therapies.

Case 1: Treatment-Resistant AC in an Adolescent

The first case researchers presented was that of a 16-year-old, otherwise healthy boy who presented with rapidly worsening AC affecting multiple body areas. Initial therapy with isotretinoin and systemic prednisolone yielded little progress and led to adverse effects including mood swings and depression. Despite aggressive escalation of therapy and procedural interventions (including cyst drainage and intralesional triamcinolone), the patient’s condition deteriorated. After 6 months of refractory disease and a cumulative isotretinoin dose of 110 mg/kg, clinicians introduced bimekizumab at 320 mg subcutaneously—an off-label use based on its anti-inflammatory mechanism of action. The therapy was injected at 4, 8, 12, and 16 weeks, then every 2 months.

Researchers found the results to be striking. Within 8 weeks and 2 doses, they stated that the patient experienced a drop from 93 to 21 acne lesions, marking a dramatic clinical turnaround.

Case 2: Years of Unrelenting AC in a Young Adult

The study then presented the second patient, a 22-year-old man, who had struggled with chronic AC for over 3 years. Researchers stated a similar pattern emerged: Prolonged isotretinoin therapy (180-mg/kg cumulative dose) and systemic steroids failed to improve symptoms and instead exacerbated psychological distress. Upon switching to bimekizumab under the same protocol as the first case, the response mirrored the adolescent’s: Lesion count fell from 298 to 85 after just 2 injections.

Understanding the Mechanism

Recent advances in dermatologic immunology have shifted attention toward the IL-17/Th17 pathway as a key player in AC’s pathology. Interleukins 17A and 17F are critical in the upregulation of inflammatory cytokines, with Cutibacterium acnes acting as a known trigger. Bimekizumab’s dual inhibition of IL-17A and IL-17F offers a unique therapeutic advantage: modulating a central driver of inflammation at 2 biologically significant points.

The study noted that this mechanism has already shown promise in other inflammatory skin diseases. Recently, bimekizumab earned FDA approval for hidradenitis suppurativa, which shares clinical and inflammatory overlap with AC, including elevated IL-17 levels in lesional tissue.

Moving Toward a New Standard

While these 2 cases do not establish bimekizumab as a mainstream therapy for AC, they highlight the drug’s potential to significantly reduce lesion burden and perhaps even mitigate the psychological adverse effects associated with long-standing disease and ineffective treatments. Both patients had exhausted traditional therapeutic avenues, and both responded rapidly and positively to the biologic intervention.

These reports join a growing interest in biologic agents as viable alternatives for treatment-resistant dermatologic conditions. However, as the authors emphasized, larger controlled trials are needed to fully evaluate safety, durability of response, and optimal dosing regimens in AC populations.

In a condition where progress has often been frustratingly slow, these 2 cases offer a rare glimpse of rapid, meaningful clinical improvement—and hope for what the next generation of acne treatment might hold.

References

1. Greydanus DE, Azmeh R, Cabral MD, Dickson CA, Patel DR. Acne in the first three decades of life: an update of a disorder with profound implications for all decades of life. Dis Mon. 2021;67(4):101103. doi:10.1016/j.disamonth.2020.101103

2. Greywal T, Zaenglein AL, Baldwin HE, et al. Evidence-based recommendations for the management of acne fulminans and its variants. J Am Acad Dermatol. 2017;77(1):109-117. doi:10.1016/j.jaad.2016.11.028

3. Yiu ZZ, Madan V, Griffiths CE. Acne conglobata and adalimumab: use of tumour necrosis factor-α antagonists in treatment-resistant acne conglobata, and review of the literature. Clin Exp Dermatol. 2015;40(4):383-386. doi:10.1111/ced.12540

4. Madanchi M, Jeker F, Juratli HA, Curatolo R. Acne conglobata and bimekizumab. JAMA Dermatol. 2025;161(6):666-668. doi:10.1001/jamadermatol.2025.0416