A case of erythrodermic psoriasis rapidly and successfully treated with Bimekizumab

Erythrodermic psoriasis (EP) is a rare variant of psoriasis characterized by a severe, in some cases life-threatening, clinical course.1 EP affects about 1%–2% of psoriasis patients with generalized erythema and scaling covering the entire body surface.2 In recent years, numerous therapeutic alternatives are available for EP treatment; however, there are still no standardized international guidelines, and most biologics are used on the basis of clinical practice, case reports, or small case series.1 Bimekizumab is a novel humanized monoclonal antibody that neutralizes both interleukin (IL)-17A and IL-17F.3 IL-17A and IL-17F have been shown to be functionally dysregulated in different immune-mediated inflammatory diseases such as psoriasis and psoriatic arthritis.3 Given the overlapping biology of these two cytokines, Bimekizumab was developed in order to provide a greater depth of clinical response rather than IL-17A inhibition alone.3 It has been recently approved for the treatment of moderate-to-severe plaque psoriasis in adults who are candidates for systemic therapy.3 Bimekizumab use in EP, as the case of the other biological drugs, is still off label. Herein, we present, to the best of our knowledge, the first case of EP rapidly and successfully treated with bimekizumab. A 40-year-old Indian man was admitted at our outpatient Clinic on June 2022 presenting widespread and confluent erythematous-desquamative plaques covering almost 90% of the body surface area (BSA). His medical history was unremarkable except for psoriasis, and he did not take any medications. The patient has been suffering from plaque-type psoriasis for 4 years. He had been previously treated with Narrowband-UVB phototherapy and, subsequently, with methotrexate without significant improvement. He therefore started adalimumab in 2019, with almost complete skin clearance. Following the onset of COVID-19 pandemic, the patient suspended outpatient follow-ups and adalimumab treatment, experiencing a progressive worsening of the disease. Dermatological examination showed a generalized erythema with associated desquamation (PASI: 55—BSA: 90%; Figure 1), associated with asthenia. Blood examination revealed elevated C reactive protein (4.5 mg/dl, nv <0.50 mg/dl). Given the severity of the disease and the huge impact on quality of life, we decided to start anti-IL-17 treatment, since these drugs have been showed as the fastest biologic for psoriasis.4 Treatment with bimekizumab administered at labeled dosage led to a complete remission (PASI100) already at Week 4 maintained up to Week 8 (Figure 2). The patient still presented PASI100 response at the last follow-up (Week 12) without referring any adverse event. Bimekizumab differs from other anti-IL17 drugs because it selectively inhibits IL-17F in addition to IL-17A.2, 5 Dual inhibition of IL-17A and IL-17F is highly effective for both naive and bio-experienced psoriasis subjects.2, 5 EP typically express accumulation of IL-17-producing cells in psoriatic skin lesions similar to plaque psoriasis.6 Dual blockage of IL-17A and IL-17F may result in inhibiting pathogenic Th17 cells and consequently downstream production of multiple effector cytokines such as IL-22 and TNF-α.7 Data from three Phase III, multicenter, randomized, double-blind, placebo- and comparator-controlled clinical trials showed bimekizumab superior efficacy over adalimumab, ustekinumab, and secukinumab.8-10 In all phase 3 trials, bimekizumab was also well tolerated, with a safety profile similar to the other biologic drugs tested, except for a higher frequency of oral candidiasis.8-10 To date, no real-life experiences or case series regarding bimekizumab for psoriasis are available in literature, due to its very recent approval. We herein present the first case of EP successfully and rapidly treated with bimekizumab, reaching PASI100 already at Week 4 maintaining response up to Week 12. To the best of our knowledge, this is the first case report of EP successfully treated with bimekizumab, showing also an excellent safety profile. However, further studies are needed in order to better define guidelines for EP treatment. M. M.: conceptualization, validation, visualization, writing-original draft preparation, writing-review & editing. T. B.: conceptualization, validation, visualization, writing-original draft preparation, writing-review & editing. L. P.: data curation, formal analysis, investigation, visualization, writing-original draft preparation. A. A.: data curation, formal analysis, investigation, visualization, writing-original draft preparation. V. V.: data curation, formal analysis, investigation, visualization, writing-original draft preparation. G. F.: conceptualization, validation, visualization, writing-original draft preparation, writing-review & editing. V. P.: conceptualization, validation, visualization, writing-original draft preparation, writing-review & editing. All authors read and approved the final version of the manuscript. The patients in this manuscript have given written informed consent to publication of their case details. None to declare. None of the contributing authors has any conflict of interest, including specific financial interests or relationships and affiliation relevant to the subject matter or discussed materials in the manuscript. Patient gave the informed consent for publication of the case.