Advancements in Bullous Pemphigoid Treatment: A Comprehensive Pipeline Update

ABASTRACT

Bullous pemphigoid (BP) is a common autoimmune bullous disease affecting mainly the elderly, with rising incidence due to increased life expectancy. This disease is characterized by tense bullous lesions on normal or erythematous skin, accompanied by pruritus. BP pathogenesis involves autoantibodies against hemidesmosomal proteins BP180 and BP230, leading to detachment at the dermo-epidermal junction as well as blister formation. BP is associated with coexisting comorbidities and drug exposure, and its management often requires high doses or chronic use of systemic glucocorticoids, posing risks of adverse effects. This review focuses on novel treatment options for BP, exploring therapies targeting different immune pathways. Rituximab, a CD20 monoclonal antibody, depletes B-lymphocytes and has shown efficacy in severe cases. Dupilumab, targeting interleukin (IL)-4 receptor α and thus blocking IL-4 and IL-13, downregulates type 2 helper (Th2) responses and has demonstrated promising results. Targeting eosinophil-related molecules using bertilimumab and AKST4290 has yielded positive results in clinical trials. Omalizumab, an immunoglobulin (Ig) E antibody, can reduce disease severity and allows corticosteroid tapering in a number of cases. Complement inhibitors such as nomacopan and avdoralimab are being investigated. IL-17 and IL-23 inhibitors such as secukinumab and tildrakizumab have shown potential in a limited number of case reports. Neonatal Fc receptor antagonists such as efgartigimod are under investigation. Additionally, topical therapies and Janus kinase inhibitors are being explored as potential treatments for BP. These novel therapies offer promising alternatives for managing BP, with potential to improve outcomes and reduce high cumulative doses of systemic corticosteroids and related toxicities. Further research, including controlled clinical trials, is needed to establish their efficacy, safety, and optimal dosing regimens for BP management.

Can Methotrexate Be Employed as Monotherapy for Bullous Pemphigoid? Analysis of Efficiency and Tolerance of Methotrexate Treatment in Patients with Bullous Pemphigoid

The European Academy of Dermatology and Venerology (EADV) consensus states that the treatment of choice for bullous pemphigoid is systemic glucocorticosteroid therapy. Bearing in mind that long-term steroid therapy is associated with numerous side effects, an effective and safer treatment regimen for these patients is still being sought. A retrospective analysis was performed of the medical reports of patients with diagnosed bullous pemphigoid. The study included 40 patients with moderate or severe disease, and who had continued ambulatory treatment for at least six months. The patients were divided into two groups: one treated with methotrexate in monotherapy, or with combined methotrexate and systemic steroid therapy. A slightly better survival rate was noted in the methotrexate group. No significant differences were observed between the groups in time to achieve clinical remission. The combination therapy group demonstrated more frequent disease recurrence and exacerbations during treatment, and a higher mortality rate. None of the patients in either group presented with severe side effects related to methotrexate treatment. The treatment of bullous pemphigoid with methotrexate in monotherapy is an effective and safe therapeutic method for elderly patients.

How Do Experts Treat Patients with Bullous Pemphigoid around the World? An International Survey

Many treatments are currently proposed for treating patients with bullous pemphigoid (BP). We assessed treatment modalities of BP depending on the different countries, BP extent, and patients' comorbidities. We surveyed worldwide experts about how they treat patients with BP. A total of 61 experts from 27 countries completed the survey. Severe and moderate BP were treated with oral prednisone (61.4 and 53.7%, respectively) or superpotent topical corticosteroids (CSs) (38.6 and 46.3%, respectively). Conventional immunosuppressants were more frequently combined with oral prednisone (74.5%) than with superpotent topical CS (37.5%) in severe BP. Topical CSs were mainly used in Europe in mild (81.1%), moderate (55.3%), and severe (54.3%) BP. In the United States of America and Asia, systemic CSs were mainly proposed for treating severe (77.8 and 100%, respectively), moderate (70 and 77.8%, respectively), and also mild (47.1 and 33.3%, respectively) BP. Most experts reduced the initial dose of oral CS in patients with diabetes mellitus (48.1%) or cardiac insufficiency (40.2%) but rarely changed BP treatment in patients with neurological disorders or neoplasia. This survey showed major differences in the way patients with BP are treated between AmeriPac countries (United State of America, Latin America, and Australia) and Asia on the one hand and Europe and the Middle East on the other hand.

Updated S2 K guidelines for the management of bullous pemphigoid initiated by the European Academy of Dermatology and Venereology (EADV)

BACKGROUND

Bullous pemphigoid (BP) is the most common autoimmune subepidermal blistering disease of the skin and mucous membranes. This disease typically affects the elderly and presents with itch and localized or, most frequently, generalized bullous lesions. A subset of patients only develops excoriations, prurigo-like lesions, and eczematous and/or urticarial erythematous lesions. The disease, which is significantly associated with neurological disorders, has high morbidity and severely impacts the quality of life.

OBJECTIVES AND METHODOLOGY

The Autoimmune blistering diseases Task Force of the European Academy of Dermatology and Venereology sought to update the guidelines for the management of BP based on new clinical information, and new evidence on diagnostic tools and interventions. The recommendations are either evidence-based or rely on expert opinion. The degree of consent among all task force members was included.

RESULTS

Treatment depends on the severity of BP and patients' comorbidities. High-potency topical corticosteroids are recommended as the mainstay of treatment whenever possible. Oral prednisone at a dose of 0.5 mg/kg/day is a recommended alternative. In case of contraindications or resistance to corticosteroids, immunosuppressive therapies, such as methotrexate, azathioprine, mycophenolate mofetil or mycophenolate acid, may be recommended. The use of doxycycline and dapsone is controversial. They may be recommended, in particular, in patients with contraindications to oral corticosteroids. B-cell-depleting therapy and intravenous immunoglobulins may be considered in treatment-resistant cases. Omalizumab and dupilumab have recently shown promising results. The final version of the guideline was consented to by several patient organizations.

CONCLUSIONS

The guidelines for the management of BP were updated. They summarize evidence- and expert-based recommendations useful in clinical practice.

Methylprednisolone Plus Low-Dose Methotrexate for Bullous Pemphigoid-A Single Center Retrospective Analysis

Monomodal systemic glucocorticoids remain the mainstay of treatment for bullous pemphigoid (BP). In this retrospective, single-arm study, we evaluated the feasibility (efficacy and tolerability) of the combination of methylprednisolone and low-dose (up to 12.5 mg/week) methotrexate (MP + MTX) for BP. At week 12, 53/55 (96.4%) patients initiated on MP + MTX during a five-year period (potential follow up time: ≥4 years) remained on treatment. At this time-point, BP remission was achieved in all compliant patients (including n = 24 cases of dipeptidyl peptidase-4 inhibitors-associated BP; 12-week remission rate: 100% [95% CI: 91.9–100.0%]; mean time to remission: 29.5 days, SEM: 2.3 days) at a mean cumulative MP dose to disease control of 678.4 mg (SEM = 49.4 mg). Eight patients relapsed during follow up (10.81 [95% CI: 5.16–21.72] relapses/100 person years, py), and seven manifested a severe adverse event (6.80 [95% CI: 3.00–14.28] severe adverse events/100 py); however, 73.4% (±7.9%) had suffered neither a relapse nor a SAE at the three-years follow up. Continuing low dose MP intake (≤8 mg/day) beyond week 12 in combination with MTX minimized the risk of a feasibility limiting event (p = 0.013). Conclusively, the combination of methylprednisolone with methotrexate is a promising, safe, and efficient modality for BP patients, which enables rapid glucocorticoid tapering.

On which evidence can we rely when prescribing off-label methotrexate in dermatological practice? - a systematic review with GRADE approach

If an authorized drug is prescribed for a use that is not described in the Summary of Product Characteristics, this is defined as 'off-label use.' Methotrexate is often used off-label for dermatological indications. Off-label use is permitted if physicians can justify the treatment based on scientific evidence available to them. Our objective here was therefore to summarize the evidence for the effectiveness, efficacy, and safety of the dermatological off-label use of methotrexate in a systematic review. We searched MEDLINE, EMBASE, and CENTRAL for studies for evidence on the effectiveness, efficacy, and safety of the off-label use of methotrexate in dermatological indications up to November 2019. We used the GRADE system to rate the quality of the evidence. The search retrieved 34,583 hits of which 3566 were selected after the title and abstract screening. After the full-text screening, 143 studies were included, which involved 3688 patients in total. We found low-quality evidence for the effectiveness, efficacy, and safety of the off-label use of methotrexate in 31 dermatological diseases. To optimize the quality of evidence to support off-label use, we need high-quality studies in which well-characterized patients are treated with standardized treatments regimens using well-validated outcomes relevant to patients and physicians.

Subepithelial autoimmune bullous dermatoses disease activity assessment and therapy

Subepidermal (subepithelial) autoimmune blistering dermatoses are a group of rare skin disorders characterized by the disruption of the dermal-epidermal junction through the action of autoantibodies. The fourth article in this continuing medical education series presents the current validated disease activity scoring systems, serologic parameters, treatments, and clinical trials for bullous pemphigoid, mucous membrane pemphigoid, epidermolysis bullosa acquisita, bullous systemic lupus erythematosus, anti-p200 pemphigoid, linear IgA bullous dermatosis, and dermatitis herpetiformis.

Treatment of Bullous Pemphigoid in People Aged 80 Years and Older: A Systematic Review of the Literature

BACKGROUND

Bullous pemphigoid commonly affects older adults and has a detrimental effect on both quality of life and longevity. Systemic corticosteroids, the mainstay of therapy, may cause significant adverse effects, especially in older patients. Therefore, safer therapeutic options are being sought.

OBJECTIVE

The objective of this article was to systematically review the published evidence on the efficacy and safety of different treatment modalities for bullous pemphigoid in older patients.

METHODS

We performed a systematic review of all publications until May 2020 in PubMed, Google Scholar, and the ongoing trials registry of the US National Institutes of Health databases evaluating the efficacy and safety of bullous pemphigoid treatments in patients aged older than 80 years. The primary outcome was complete response. The secondary outcomes were partial response, complete remission on minimal therapy or during tapering, recurrence, adverse events, and mortality.

RESULTS

Twenty-eight publications were included: 2 randomized controlled trials, 5 prospective cohort studies, 10 retrospective cohort studies, and 11 case series, with a total of 153 older patients. The overall complete response rate was 31%. Topical corticosteroids had the highest complete response rate (55%) with a low side-effect profile. Biologics (omalizumab and rituximab) were effective in achieving complete remission on minimal therapy (29%) without recurrence, although rituximab was associated with a relatively high mortality rate (29%).

CONCLUSIONS

Current data suggest that topical corticosteroids are effective and safe and should remain the first line of treatment for bullous pemphigoid in older adults. However, their application is difficult and requires a high-functioning patient, third-party assistance, or a relatively mild disease. Biological agents are effective but warrant meticulous patient selection owing to the relatively high mortality rate associated with rituximab.

CLINICAL TRIAL REGISTRATION

PROSPERO registration number CRD42020186686.

Japanese guidelines for the management of pemphigoid (including epidermolysis bullosa acquisita)

The pemphigoid group is a category of autoimmune subepidermal blistering diseases in which autoantibodies deposit linearly at the epidermal basement membrane zone (BMZ). The main subtypes of pemphigoid mediated by immunoglobulin G autoantibodies are bullous pemphigoid (BP), mucous membrane pemphigoid (MMP) and epidermolysis bullosa acquisita (EBA). To establish the first guidelines approved by the Japanese Dermatological Association for the management of pemphigoid diseases, the Committee for Guidelines for the Management of Pemphigoid Diseases (Including EBA) was founded as part of the Study Group for Rare Intractable Skin Diseases under the Ministry of Health, Labor and Welfare Research Project on Overcoming Intractable Diseases. These guidelines aim to provide current information for the management of BP, MMP and EBA in Japan. Based on evidence, the guidelines summarize the clinical and immunological manifestations, pathophysiologies, diagnostic criteria, disease severity determination criteria, treatment algorithms and treatment recommendations. Because of the rarity of these diseases, there are few clinical studies with a high degree of evidence, so several parts of these guidelines were established based on the opinions of the Committee. To further optimize these guidelines, periodic revision in line with the new evidence is necessary.

A Case of Nivolumab-Induced Bullous Pemphigoid: Review of Dermatologic Toxicity Associated with Programmed Cell Death Protein-1/Programmed Death Ligand-1 Inhibitors and Recommendations for Diagnosis and Management

Immunotherapy has emerged as a highly effective treatment for numerous cancers. Use of checkpoint inhibitors against various molecules including programmed cell death protein-1 (PD-1), programmed death ligand-1 (PD-L1), and cytotoxic T-lymphocyte-associated protein-4 have become widespread in clinical practice. Compared with conventional chemotherapy, immunotherapy is associated with a unique set of immune reactions known collectively as immune-related adverse events (irAEs). Of known irAEs, cutaneous toxicity is among the most frequently observed in patients treated with immunotherapy. Although often mild, dermatologic toxicity can occasionally be high grade and potentially life-threatening. In this article, we report a case of PD-1 inhibitor-induced bullous pemphigoid-a serious adverse event that has been increasingly observed with use of PD-1/PD-L1 inhibitors. We will also review diagnosis and management of low-grade cutaneous irAEs and bullous disease with checkpoint inhibitors.

KEY POINTS

PD-1/PD-L1 inhibitor-induced bullous pemphigoid (BP) is a rare but potentially serious dermatologic toxicity associated with checkpoint inhibitorsIn patients with pruritus or rash that is refractory to topical steroids, physicians should have a greater index of suspicion for higher-grade cutaneous immune-related adverse events.There is no standardized treatment algorithm for management of PD-1/PD-L1 inhibitor-induced BP, but patients frequently require topical and systemic steroids.

Bullous Pemphigoid: A Review of its Diagnosis, Associations and Treatment

Bullous pemphigoid (BP) is the most common autoimmune subepidermal blistering disease in Western countries, and typically affects the elderly. BP is immunologically characterized by tissue-bound and circulating autoantibodies directed against either the BP antigen 180 (BP180, or BPAG2) or the BP antigen 230 (BP230, or BPAG1e), or even both, which are components of hemidesmosomes involved in the dermal-epidermal cohesion. Risk factors for BP include old age, neurologic diseases (dementia, Parkinson's disease, cerebrovascular disease), and some particular drugs, including loop diuretics, spironolactone and neuroleptics. The spectrum of clinical presentations is extremely broad. Clinically, BP is an intensely pruritic erythematous eruption with widespread blister formation. In the early stages, or in atypical, non-bullous variants of the disease, only excoriated, eczematous or urticarial lesions (either localized or generalized) are present. The diagnosis of BP relies on immunopathologic findings, especially based on both direct and indirect immunofluorescence microscopy observations, as well as on anti-BP180/BP230 enzyme-linked immunosorbent assays (ELISAs). BP is usually a chronic disease, with spontaneous exacerbations and remissions, which may be accompanied by significant morbidity. In the past decade, potent topical corticosteroids have emerged as an effective and safe first-line treatment for BP, but their long-term feasibility is still controversial. Newer therapeutic agents targeting molecules involved in the inflammatory cascade associated with BP represent future alternatives to classical immunosuppressant drugs for maintenance therapy.

Integrating longitudinal serum IL-17 and IL-23 follow-up, along with autoantibodies variation, contributes to predict bullous pemphigoid outcome

Bullous pemphigoid (BP) is an inflammatory autoimmune bullous disease involving cytokines and proteases in the process of blister formation. Recently, IL-17 and IL-23 were evidenced in lesional skin and serum of BP patients at time of diagnosis, but their involvement in disease outcome has still not been investigated yet. We then analysed IL-17 and IL-23 serum levels during the first months of follow-up upon treatment. Compared with age- and sex- matched controls, high levels of IL-23 were observed at baseline in BP patients serum (P < 0.01), while IL-17 levels was not. However, some BP patients expressed high IL-17 serum level, independently of disease severity. In these patients, those with ongoing remission reduced IL-17 concentration upon treatment (P < 0.001), whereas IL-17 level remained elevated in patients who relapsed. Meanwhile, IL-23 serum levels increased during the first month of treatment in BP patients who later relapsed (P < 0.01) and MMP-9 serum level was not controlled. Accordingly, we found that both IL-17 and IL-23 increased MMP-9 secretion from leukocytes in-vitro. Then, we showed that elevated IL-17/IL-23 serum concentrations helped to discriminate BP patients who later relapsed. Such uncontrolled inflammatory response raises the question whether these molecules could become biological target for BP patients resistant to steroid treatment.

Positive Direct Immunofluorescence Is of Better Value than ELISA-BP180 and ELISA-BP230 Values for the Prediction of Relapse after Treatment Cessation in Bullous Pemphigoid: A Retrospective Study of 97 Patients

BACKGROUND

ELISA-BP180 values and direct immunofluorescence (DIF) are prognostic factors for relapse after treatment cessation in bullous pemphigoid (BP).

OBJECTIVE

To determine the relevance of ELISA-BP230 antibodies for predicting relapse 6 months after treatment cessation.

METHODS

We retrospectively selected patients with BP and available data from ELISA-BP180 and -BP230 and DIF performed at treatment cessation. The rate of relapse was calculated at 6 months. We compared ELISA-BP180 and -BP230 values and DIF in patients with relapse and remission.

RESULTS

We included 97 patients. At 6 months, 25.6% of patients showed relapse. The proportion of patients with an ELISA-BP230 value ≥27 UA/ml was higher, but not significantly, for those with relapse than for those with remission (p = 0.11). The frequency of positive DIF findings was significantly higher for patients with relapse (p = 0.005).

CONCLUSION

DIF is of better value than ELISA-BP180 and -230 tests to predict relapse after treatment cessation in BP.

Pemphigoid diseases

Pemphigoid diseases are a group of well defined autoimmune disorders that are characterised by autoantibodies against structural proteins of the dermal-epidermal junction and, clinically, by tense blisters and erosions on skin or mucous membranes close to the skin surface. The most common of these diseases is bullous pemphigoid, which mainly affects older people and the reported incidence of which in Europe has more than doubled in the past decade. Prognosis and treatments vary substantially between the different disorders and, since clinical criteria are usually not sufficient, direct immunofluorescence microscopy of a perilesional biopsy specimen or serological tests are needed for exact diagnosis. In eight pemphigoid diseases the target antigens have been identified molecularly, which has allowed the development of standard diagnostic assays for detection of serum autoantibodies-some of which are commercially available. In this Seminar we discuss the clinical range, diagnostic criteria, diagnostic assay systems, and treatment options for this group of diseases.