Use of biologics in Chinese pregnant patients with deficiency of interleukin-36 receptor antagonist (DITRA): A case series.

OBJECTIVE: Impetigo herpetiformis (IH) is a rare form of pustular psoriasis which may result in maternal and fetal morbidity and even mortality. Deficiency of interleukin-36 receptor antagonist (DITRA) is the most frequently identified genetic defect of IH. Currently there are no biologics approved for IH despite the revolutionary role of biologics in the treatment of plaque and pustular psoriasis. Anecdotal reports of biologics use in DITRA patients with IH are also limited. CASE REPORTS: We present herein a case series of 6 Chinese IH patients harboring IL36RN gene c.115+6T>C mutation during 8 pregnancies, treated with various biologics, including adalimumab, etanercept and secukinumab. CONCLUSION: Most pregnancy courses were uneventful, except for one woman who had recurrent episodes of decreased fetal heart rate variability after adalimumab injections, which subsided after switching to etanercept. The treatment effectiveness and safety demonstrated in our cases suggested the role of biologics for the treatment of IH in patients with DITRA.

International Consensus Definition and Diagnostic Criteria for Generalized Pustular Psoriasis From the International Psoriasis Council.

Importance: Generalized pustular psoriasis (GPP) lacks internationally accepted definitions and diagnostic criteria, impeding timely diagnosis and treatment and hindering cross-regional clinical and epidemiological study comparisons. Objective: To develop an international consensus definition and diagnostic criteria for GPP using the modified Delphi method. Evidence Review: The rarity of GPP presents a challenge in acquiring comprehensive published clinical data necessary for developing standardized definition and criteria. Instead of relying on a literature search, 43 statements that comprehensively addressed the fundamental aspects of the definitions and diagnostic criteria for GPP were formulated based on expert reviews of 64 challenging GPP cases. These statements were presented to a panel of 33 global GPP experts for voting, discussion, and refinements in 2 virtual consensus meetings. Consensus during voting was defined as at least 80% agreement; the definition and diagnostic criteria were accepted by all panelists after voting and in-depth discussion. Findings: In the first and second modified Delphi round, 30 (91%) and 25 (76%) experts participated. In the initial Delphi round, consensus was achieved for 53% of the statements, leading to the approval of 23 statements that were utilized to develop the proposed definitions and diagnostic criteria for GPP. During the second Delphi round, the final definition established was, "Generalized Pustular Psoriasis is a systemic inflammatory disease characterized by cutaneous erythema and macroscopically visible sterile pustules." It can occur with or without systemic symptoms, other psoriasis types, and laboratory abnormalities. GPP may manifest as an acute form with widespread pustules or a subacute variant with an annular phenotype. The identified essential criterion was, "Macroscopically visible sterile pustules on erythematous base and not restricted to the acral region or within psoriatic plaques." Conclusions and Relevance: The achievement of international consensus on the definition and diagnostic criteria for GPP underscores the importance of collaboration, innovative methodology, and expert engagement to address rare diseases. Although further validation is needed, these criteria can serve as a reference point for clinicians, researchers, and patients, which may contribute to more accurate diagnosis and improved management of GPP.

Acquired diffuse palmoplantar erythema with keratoderma in Chinese patients with pustular psoriasis: A predictor for IL36 receptor antagonist c.115+6T>C mutation?

Several studies have suggested that mutation of the interleukin 36 receptor antagonist gene (IL36RN) is related to generalized pustular psoriasis (GPP), and the presence of IL36RN mutation may affect the clinical manifestations and treatment responses. However, genetic testing is not routinely available in clinical practice for the diagnosis of GPP. Previously, GPP patients with acrodermatitis continua of Hallopeau (ACH) were found to have a high percentage of carrying IL36RN mutation. In this study, we reported six patients with pustular psoriasis presenting as diffuse palmoplantar erythema with keratoderma among 60 patients who carried IL36RN mutation. ACH was present in five patients and five patients had acute flare of GPP. This unique presentation may serve as a predictor for IL36RN mutation in patients with pustular psoriasis, similar to ACH.

Clinical advances in biological therapy for generalized pustular psoriasis: a review.

INTRODUCTION: In 2022, U.S. Food and Drug Administration (FDA) approved the first biologics, intravenous spesolimab, for acute flare of generalized pustular psoriasis (GPP). The drug works by blocking IL-36 signaling, the key pathway of GPP. Among the known mutations causing GPP, IL36RN mutations are most common, and the presence of IL36RN mutations had been found to affect the clinical manifestations and treatment response of GPP. AREAS COVERED: Literature search was conducted in PubMed, Embase and ClinicalTrials.gov for relevant studies discussing biologic treatment for GPP with special emphasis on larger studies, pediatric group, pregnant women, and the influence of IL36RN mutation on the effectiveness of biologics. EXPERT OPINION: The approval of spesolimab for GPP flare treatment marks a new era. However, whether spesolimab will be placed as the treatment of choice remains unknown, considering its higher cost, lack of direct comparison with existing biologics, and uncertain effects on co-existing plaque-type psoriasis. However, the demonstration of numerically better efficacy for patients carrying pathogenic IL36RN mutations suggests the role of pharmacogenetics in the choices of GPP treatment. Future randomized studies are warranted to investigate the effectiveness and safety of biologics for GPP in pediatric and pregnant groups.

Drug- or Vaccine-Induced/Aggravated Psoriatic Arthritis: A Systematic Review.

INTRODUCTION: Drugs and vaccines have been less studied as inducing or aggravating factors for psoriatic arthritis (PsA) compared with psoriasis. Thus, the present study collected and summarized the publications to date about this issue. METHODS: We conducted a systematic literature search through the PubMed, Embase, and Cochrane databases to identify all reports on potential drug- and vaccine-related PsA events until 28 February 2023. RESULTS: In total, 179 cases from 79 studies were eligible for study. Drugs commonly reported include coronavirus disease 2019 (COVID-19) mRNA vaccines (6 cases), bacillus Calmette-Guerin (BCG) vaccine (3 cases), interferon (18 cases), immune-checkpoint inhibitors (ICI) (19 cases), and biologic disease-modifying antirheumatic drugs (bDMARDs) (127 cases). Drugs causing psoriasis may also induce or aggravate PsA (6 cases). BDMARD-related PsA mostly occurred in a "paradoxical" setting, in which the bDMARDs approved for the treatment of psoriasis induce or aggravate PsA. The reported latency may be delayed up to 2 years. Peripheral arthritis (82.3%) was the most common manifestation of drug- and vaccine-related PsA, followed by dactylitis (29.1%), enthesitis (23.4%), and spondyloarthritis (17.7%). CONCLUSIONS: Drugs and vaccines may be implicated in the aggravation of PsA. Possible mechanisms include cytokine imbalance, immune dysregulation, or inadequate PsA treatment response compared with psoriasis. Most reports are case based without controls, so more studies are needed to further prove the causality. However, early recognition of factors causing or aggravating PsA is important to prevent the irreversible joint damage.

A Review of Dupilumab-Induced Adverse Events to Dermatologists and the Potential Pathogenesis in the Treatment of Atopic Dermatitis.

Dupilumab, a monoclonal antibody targeting interleukin-4 antibody, is approved for use in many type 2 inflammatory diseases, including atopic dermatitis. It is generally well tolerated with no need of routine laboratory monitoring. However, several adverse events have been reported during real-world practice and in pivotal trials. We conducted a systematic literature research of the PubMed, Medline, and Embase databases to identify articles recording the clinical manifestation and potential pathogenesis of these adverse events with interests (AEIs) to dermatologists. In total, 547 cases from 134 studies have developed 39 AEIs 1 day to 2.5 years after dupilumab treatment. The most common AEIs are facial and neck dermatitis (299 cases), psoriasis (70 cases), arthralgia (56 cases), alopecia (21 cases), cutaneous T cell lymphoma (19 cases), severe ocular diseases (19 cases), and drug eruption (6 cases). Most of the AEIs recorded in this review resolved or improved after dupilumab discontinuation or the addition of another treatment, whereas 3 of the cases died of severe AEI. The potential pathogenesis included T help type 1 (Th1)/T help type 2 (Th2) imbalance, Th2/T help type 17 (Th17) imbalance, immune reconstitution, hypersensitivity reaction, transient hypereosinophilia related, and Th1 suppression. Clinicians should be alert of these AEIs for timely diagnosis and appropriate treatment.

Pressure and Skin: A Review of Disease Entities Driven or Influenced by Mechanical Pressure.

Skin perceives and reacts to external mechanical forces to create resistance against the external environment. Excessive or inappropriate stimuli of pressure may lead to cellular alterations of the skin and the development of both benign and malignant skin disorders. We conducted a comprehensive literature review to delve into the pressure-induced and aggravated skin disorders and their underlying pressure-related mechanisms. Dysregulated mechanical responses of the skin give rise to local inflammation, ischemia, necrosis, proliferation, hyperkeratosis, impaired regeneration, atrophy, or other injurious reactions, resulting in various disease entities. The use of personal devices, activities, occupations, weight bearing, and even unintentional object contact and postures are potential scenarios that account for the development of pressure-related skin disorders. The spectrum of these skin disorders may involve the epidermis (keratinocytes and melanocytes), hair follicles, eccrine glands, nail apparatuses, dermis (fibroblasts, mast cells, and vasculature), subcutis, and fascia. Clarifying the clinical context of each patient and recognizing how pressure at the cellular and tissue levels leads to skin lesions can enhance our comprehension of pressure-related skin disorders to attain better management.

Combination of methotrexate with oral disease-modifying antirheumatic drugs in psoriatic arthritis: a systematic review.

Background: Oral conventional synthetic disease-modifying antirheumatic drugs (csDMARDs), especially methotrexate, are the cornerstone of treating psoriatic arthritis (PsA). The use of csDMARDs with biologics has increased their efficacy in psoriasis. However, the combination of two oral DMARDs in patients with PsA has not been adequately reviewed. In this study, we explore the combinational use of methotrexate with DMARDs in PsA patients. Materials & methods: A review was conducted using Medline (PubMed), Embase, Web of Science and the Cochrane Library, covering articles up to February 2023. Results & conclusion: Nine studies comprising 1993 participants were included. The evidence supporting combination therapy remains limited. Combinational therapy could be considered in patients with inadequate response to monotherapy or no access to biologics.

This study aimed to determine whether combining two different medicines could serve as an option for patients with psoriatic arthritis (PsA). Typically, doctors prescribe just one medicine, but sometimes its efficacy is limited. After reviewing nine studies with 1993 participants, it appears that using two medicines together might be an alternative option for PsA patients who do not experience sufficient relief from a single medicine. This research contributes to our understanding of using this combination approach for PsA and suggests that further larger studies could confirm its potential as a beneficial method for improving the health of these patients.

Efficacy and Safety of Spesolimab in Patients with Generalized Pustular Psoriasis: A Subgroup Analysis of Chinese Patients in the Effisayil 1 Trial.

INTRODUCTION: Generalized pustular psoriasis (GPP) is a rare and potentially life-threatening skin disease. The global Effisayil 1 study investigated the efficacy and safety of spesolimab, a humanized monoclonal antibody targeting the IL-36 receptor, in patients experiencing GPP flare. This analysis aimed to explore the efficacy and safety of spesolimab in the Chinese subgroup of Effisayil 1. METHODS: Effisayil 1 was a multicenter, randomized, double-blind, placebo-controlled phase II study. Eligible patients with a GPP flare were randomly assigned (2:1) to receive a single intravenous dose of spesolimab (900 mg) or placebo on day 1. On day 8, patients who had persistent symptoms that met a predefined criterion could receive open-label spesolimab. After day 8, patients with recurrent flares following clinical response could receive rescue treatment with open-label spesolimab. The primary end point was a Generalized Pustular Psoriasis Physician Global Assessment (GPPGA) pustulation sub-score of 0 at week 1. The key secondary end point was a GPPGA total score of 0 or 1 at week 1. RESULTS: Eleven Chinese patients were randomized, with five patients receiving spesolimab and six receiving placebo. At week 1, 60.0% (3/5) of patients in the spesolimab group and 16.7% (1/6) of patients in the placebo group achieved a GPPGA pustulation sub-score of 0 (risk difference 43.3%; 95% CI -22.6, 86.2); 60.0% and 16.7% of patients in the spesolimab and placebo group, respectively, achieved a GPPGA total score 0 or 1 (risk difference 43.3%; 95% CI -22.6, 86.2). Overall, four patients in each group of the spesolimab and the placebo groups reported at least one adverse event (AE) by week 1, with two and three reporting drug-related AEs, respectively. One patient reported a serious AE that was not considered to be drug related. No death occurred during the study period. CONCLUSION: In the Chinese subgroup of the Effisayil 1 study, more patients receiving spesolimab experienced lesion clearance than those on placebo at week 1, with an acceptable safety profile that was consistent with the global study population. TRIAL REGISTRATION: NCT03782792.

The Pressurized Skin: A Review on the Pathological Effect of Mechanical Pressure on the Skin from the Cellular Perspective.

Since human skin is the primary interface responding to external mechanical stimuli, extrinsic forces can disrupt its balanced microenvironment and lead to cutaneous lesions. We performed this review to delve into the pathological effects of mechanical pressure on skin from the cellular perspective. Fibroblasts of different subsets act as heterogeneous responders to mechanical load and express diverse functionalities. Keratinocytes relay mechanical signals through mechanosensitive receptors and the ensuing neurochemical cascades to work collaboratively with other cells and molecules in response to pressure. Mast cells release cytokines and neuropeptides, promoting inflammation and facilitating interaction with sensory neurons, while melanocytes can be regulated by pressure through cellular and molecular crosstalk. Adipocytes and stem cells sense pressure to fine-tune their regulations of mechanical homeostasis and cell differentiation. Applying mechanical pressure to the skin can induce various changes in its microenvironment that potentially lead to pathological alterations, such as ischemia, chronic inflammation, proliferation, regeneration, degeneration, necrosis, and impaired differentiation. The heterogeneity of each cellular lineage and subset from different individuals with various underlying skin conditions must be taken into consideration when discussing the pathological effects of pressure on the skin. Thus, elucidating the mechanotransduction and mechanoresponsive pathways from the cellular viewpoint is crucial in diagnosing and managing relevant dermatological disorders.

Effectiveness of Biologics, Patient-Reported Outcomes, and Clinical Photography in a Subset of Patients with Moderate-to-Severe Psoriasis: Week 12 Results from the Psoriasis Study of Health Outcomes (PSoHO).

Purpose: Since skin is highly accessible, clinical photography is a useful tool to visually substantiate the real-world effectiveness outcomes of biologic-treated adults with moderate-to-severe psoriasis (PsO). We report the effectiveness and patient-reported outcomes at Week 12 between anti-interleukin (IL)-17A biologics and other biologics as well as ixekizumab and guselkumab in patients with available clinical photography at baseline and Week 12. Patients and Methods: The Psoriasis Study of Health Outcomes (PSoHO) is an international, non-interventional, cohort study investigating the effectiveness of biologics in adults with moderate-to-severe psoriasis at Week 12. Outcomes included the proportion of patients who achieved 90% improvement in Psoriasis Area and Severity Index (PASI90) and/or static Physician Global Assessment (sPGA) 0/1 (primary endpoint), PASI100, PASI90, Dermatology Life Quality Index (DLQI), and Itch Numeric Rating Scale (NRS) (secondary endpoints) at Week 12. Data are reported descriptively. Results: This analysis included 59 biologic-treated (23 anti-IL-17A; 36 other biologics) patients with available clinical photographs from the overall PSoHO study (n=1981). At baseline, the mean (standard deviation [SD]) age was 45.7 (11.1) years, 71.2% were male, 52.5% were bio-experienced and the median (interquartile range) duration of disease was 10.5 (12.4) years. Mean (SD) PASI was 16.9 (9.3) and sPGA was 3.5 (0.8). At Week 12, 65.2%/47.2% of the anti-IL-17A/other biologics cohort achieved the primary outcome. Response rates for PASI90/100 were numerically higher with anti-IL-17A than with other biologics. Patients receiving anti-IL-17A had numerically better outcomes for DLQI 0/1 and Itch NRS than those receiving other biologics at Week 12. Clinical photographs confirmed skin improvements in ixekizumab- and guselkumab-treated patients. Conclusion: This subgroup analysis showed that anti-IL-17A biologics are effective at rapidly improving signs and symptoms of PsO and improving quality of life. Additionally, serial photography provided visual evidence of biologic treatment response over time.

Predictors for the effectiveness of 75 mg risankizumab in treating psoriasis-A real-word evidence from a 52-week retrospective study.

In the registration trial of risankizumab for patients with moderate-to-severe psoriasis in Japan, similar Psoriasis Area Severity Index (PASI) responses were observed for 75 mg or 150 mg risankizumab at most time points up to 52 weeks, except for PASI 100 at week 16. The use of 75 mg risankizumab offers an attractive option considering the high cost of risankizumab. However, it is unknown whether patients with mild-to-moderate psoriasis respond similarly, and the efficacy data of non-Japanese patients is also lacking. We retrospectively included 30 consecutive Chinese patients receiving half-dose (75 mg) risankizumab as scheduled up to 52 weeks. Compared with biologic-experienced group, biologic-naive group had a significantly higher PASI 50/75/90/100 achievement (p = 0.0098/0.0039/0.0016/0.0054) at week 52. PASI 50/75/90/100 curves in biologic-naive group (p = 0.0117/0.0239/0.0143/0.0269) were also significantly higher when analysed generalized estimating equations (GEE) model. Though there was no statistically significant difference in terms of PASI 50/75/90/100 responses at any time points between those with body weight ≦ 65 kg and those >65 kg, a tendency of secondary failure was noted in those >65 kg from week 40 onwards. Patients who were both biologic-naive and weighed ≦ 65 kg achieved sustained PASI 50/75/90 responses from week 16/28/40 onwards, respectively, indicating that they could be considered as potential candidates for 75 mg risankizumab. Though PASI 75 curve in patients without diabetes mellitus (DM) surpassed that in patient without DM, curves of other parameters did not reach significance when analysed by GEE model. There was no HBV, HCV or TB reactivation, nor other new safety signals during the 52-week observational period. Providing risankizumab with flexible dosing options is beneficial in clinical practice considering the high cost of this medication.

Five-year Maintenance of Clinical Response and Consistent Safety Profile for Guselkumab in Asian patients with Psoriasis from VOYAGE 1 and VOYAGE 2.

INTRODUCTION: Guselkumab is a human monoclonal antibody against IL-23 used in the treatment of moderate-to-severe psoriasis. This post-hoc analysis evaluated the efficacy and safety of guselkumab in the Asian subpopulation of VOYAGE 1 and VOYAGE 2 through 5 years. METHODS: The proportions of guselkumab-treated Asian patients (VOYAGE 1 and 2) achieving Psoriasis Area and Severity Index (PASI) 90 and PASI 100, Investigator's Global Assessment (IGA) scores of 0/1 and 0, and Dermatology Life Quality Index (DLQI) scores of 0/1 (week 100 through week 252) were assessed. Non-responders were patients who met the treatment failure rules. Efficacy endpoints were analyzed using the as-observed methodology (no missing data imputation) for both studies and using non-responder imputation (for patients with any missing data) in VOYAGE 1. Safety outcomes were based on pooled data through week 252. RESULTS: Response rates through week 252 for 199 Asian patients in the guselkumab group in VOYAGE 1 and VOYAGE 2, respectively, were 76.8% and 80.6% (PASI 90), 26.8% and 38.7% (PASI 100), 64.3% and 87.1% (IGA 0/1), and 26.8% and 45.2% (IGA 0). DLQI (0/1) at week 252 was achieved by 52.7% of patients in VOYAGE 1 and 61.3% in VOYAGE 2, while DLQI (0) at week 252 was achieved by 32.7% of patients in VOYAGE 1 and 40.3% in VOYAGE 2. The safety profile was similar to the global population and remained consistent through 5 years. Asian patients were followed for a total of 814 patient-years (PY). Over 85% of the guselkumab-treated patients continued treatment through week 264. The rate of serious adverse events (AEs) at week 252 was 3.07/100 PY. Rates of AEs of interest were low: serious infections, 0.74/100 PY; nonmelanoma skin cancer (NMSC), no patients; malignancies other than NMSC, 0.12/100 PY; and no major adverse cardiovascular events (MACE). CONCLUSION: These analyses confirm a continuous response over 5 years, indicating that guselkumab shows therapeutic longevity in Asian patients requiring long-term treatment for moderate-to-severe psoriasis. TRIAL REGISTRATION: ClinicalTrials.gov identifiers: VOYAGE 1 [NCT02207231] and VOYAGE 2 [NCT02207244].

Psoriasis­a long-term condition that causes a skin rash with scaly, itchy patches (plaques)­is becoming more prevalent in Asia. To control symptoms of moderate-to-severe psoriasis and achieve a strong improvement in the patient's quality of life, continuous treatment is usually needed. Guselkumab is a medicine that targets specific parts of the immune system to treat moderate-to-severe psoriasis. It is important to understand the long-term benefits of guselkumab in Asian patient populations. Our study analyzed the data from two randomized clinical trials (called VOYAGE 1 and VOYAGE 2) that studied people with moderate-to-severe plaque psoriasis. We examined results for the 199 people from Asia, including Korea and Taiwan, who took part in these studies. Overall, 162 of the 184 (86.6%) people from Asia treated with guselkumab incorporated into these studies continued the treatment for 5 years. Patients treated with guselkumab showed effective clinical responses (improvements measured by clinicians), including high skin clearance, meaning a large reduction in skin surface area affected by psoriasis. On guselkumab, patients also reported improvements in their skin-related health-related quality of life. These improvements and the efficacy of guselkumab were maintained over 5 years of follow-up. The safety results for guselkumab in the Asian subpopulation were similar to those for the global population, showing low rates of serious adverse effects, as expected from this type of medicine. Overall, our study found a favorable benefit­risk profile with continuous guselkumab treatment for 5 years in Asian people with moderate-to-severe psoriasis. This highlights that guselkumab treatment allows long-lasting control of this disease.

Efficacy of Baricitinib in Patients with Various Degrees of Alopecia Areata Severity: Post-Hoc Analysis from BRAVE AA1 and BRAVE AA2.

BACKGROUND: Baricitinib, an oral selective JAK1/JAK2 inhibitor, is approved for the treatment of adults with severe alopecia areata (AA). OBJECTIVE: To evaluate differences in response up to week 52 among subgroups based on the baseline severity of AA assessed with the Severity of Alopecia Tool (SALT) score. METHODS: Data were pooled from BRAVE-AA1 and BRAVE-AA2, two randomized, placebo-controlled, phase 3 trials, which enrolled adults with a SALT score ≥ 50. Patients were subdivided by the degree of AA severity at baseline. RESULTS: Among the 855 patients treated with baricitinib 2 mg and 4 mg, improvements in scalp hair growth continued through to week 52. A superior response was observed in patients with a SALT score of 50-94 versus a score of 95-100. Patients on baricitinib 4 mg had a faster and higher response rate compared to baricitinib 2 mg. CONCLUSION: Across all degrees of severity for baricitinib 2 mg and 4 mg doses, the proportion of patients responding was yet to plateau up to week 52. Response to treatment was longer for patients with a baseline SALT score 95-100. Further studies are needed to analyze other parameters that may impact observed response rates.

Efficacy and safety of subcutaneous spesolimab for the prevention of generalised pustular psoriasis flares (Effisayil 2): an international, multicentre, randomised, placebo-controlled trial.

BACKGROUND: Spesolimab is an anti-interleukin-36 receptor monoclonal antibody approved to treat generalised pustular psoriasis (GPP) flares. We aimed to assess the efficacy and safety of spesolimab for GPP flare prevention. METHODS: This multicentre, randomised, placebo-controlled, phase 2b trial was done at 60 hospitals and clinics in 20 countries. Eligible study participants were aged between 12 and 75 years with a documented history of GPP as per the European Rare and Severe Psoriasis Expert Network criteria, with a history of at least two past GPP flares, and a GPP Physician Global Assessment (GPPGA) score of 0 or 1 at screening and random assignment. Patients were randomly assigned (1:1:1:1) to receive subcutaneous placebo, subcutaneous low-dose spesolimab (300 mg loading dose followed by 150 mg every 12 weeks), subcutaneous medium-dose spesolimab (600 mg loading dose followed by 300 mg every 12 weeks), or subcutaneous high-dose spesolimab (600 mg loading dose followed by 300 mg every 4 weeks) over 48 weeks. The primary objective was to demonstrate a non-flat dose-response curve on the primary endpoint, time to first GPP flare. FINDINGS: From June 8, 2020, to Nov 23, 2022, 157 patients were screened, of whom 123 were randomly assigned. 92 were assigned to receive spesolimab (30 high dose, 31 medium dose, and 31 low dose) and 31 to placebo. All patients were either Asian (79 [64%] of 123) or White (44 [36%]). Patient groups were similar in sex distribution (76 [62%] female and 47 [38%] male), age (mean 40·4 years, SD 15·8), and GPP Physician Global Assessment score. A non-flat dose-response relationship was established on the primary endpoint. By week 48, 35 patients had GPP flares; seven (23%) of 31 patients in the low-dose spesolimab group, nine (29%) of 31 patients in the medium-dose spesolimab group, three (10%) of 30 patients in the high-dose spesolimab group, and 16 (52%) of 31 patients in the placebo group. High-dose spesolimab was significantly superior versus placebo on the primary outcome of time to GPP flare (hazard ratio [HR]=0·16, 95% CI 0·05-0·54; p=0·0005) endpoint. HRs were 0·35 (95% CI 0·14-0·86, nominal p=0·0057) in the low-dose spesolimab group and 0·47 (0·21-1·06, p=0·027) in the medium-dose spesolimab group. We established a non-flat dose-response relationship for spesolimab compared with placebo, with statistically significant p values for each predefined model (linear p=0·0022, emax1 p=0·0024, emax2 p=0·0023, and exponential p=0·0034). Infection rates were similar across treatment arms; there were no deaths and no hypersensitivity reactions leading to discontinuation. INTERPRETATION: High-dose spesolimab was superior to placebo in GPP flare prevention, significantly reducing the risk of a GPP flare and flare occurrence over 48 weeks. Given the chronic nature of GPP, a treatment for flare prevention is a significant shift in the clinical approach, and could ultimately lead to improvements in patient morbidity and quality of life. FUNDING: Boehringer Ingelheim.