Burden of pemphigus vulgaris with a particular focus on women: A review

Pemphigus vulgaris is a chronic autoimmune mucocutaneous blistering disorder. Apart from the disease itself, other aspects of patients' life, including psychological, social, and financial, can be affected. Women are particularly more disposed to the impact of the disease due to their physiological characteristics, the specific periods of pregnancy and lactation as well as their social and familial role. In this review, we summarized the burden of pemphigus vulgaris on various aspects of women's lives. It is essential to understand these problems and provide appropriate support for patients with such a burdensome disease.

Cost-Utility Analysis of Rituximab vs Mycophenolate Mofetil for the Treatment of Pemphigus Vulgaris

Importance

There is an increasing body of literature that supports the use of rituximab as a first-line steroid-sparing agent in pemphigus vulgaris. However, the cost of rituximab is substantial compared with conventional agents, and there are limited health economic data to justify its use.

Objective

To evaluate the cost-effectiveness of rituximab biosimilars relative to mycophenolate mofetil as a first-line steroid-sparing agent for moderate to severe pemphigus vulgaris.

Design, Setting, and Participants

A cost-utility analysis over a 24-month time horizon was conducted from the perspective of the Australian health care sector using a modeled cohort of treatment-naive adult patients with moderate to severe pemphigus vulgaris. A Markov cohort model was constructed to simulate disease progression following first-line treatment with rituximab biosimilars or mycophenolate mofetil. The simulated cohort transitioned between controlled disease, uncontrolled disease, and death. Efficacy and utility data were obtained from available published literature. Cost data were primarily obtained from published government data. One-way and probabilistic sensitivity analyses were performed to assess uncertainty. Primary outcomes were the changes in cost and quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratio (ICER) over the 24 months.

Interventions

Rituximab biosimilars and mycophenolate mofetil.

Results

The simulated cohort of treatment-naive patients had a mean age of 50.8 years, a female-to-male ratio of 1.24, and moderate to severe disease as classified by the Harman criteria. First-line rituximab biosimilars were associated with a cost reduction of AU$639 and an improvement of 0.07 QALYs compared with mycophenolate mofetil, resulting in an ICER of -AU$8818/QALY. Rituximab biosimilars were therefore more effective and less costly compared with mycophenolate mofetil. Sensitivity analyses demonstrated that rituximab biosimilars remained cost-effective across a range of values for cost, utility, and transition probability input parameters and willingness-to-pay thresholds.

Conclusions and Relevance

In this cost-utility analysis, rituximab biosimilars were cost-effective compared with mycophenolate mofetil for moderate to severe pemphigus vulgaris. Further investigation into its cost-effectiveness over a longer time horizon is necessary, but the favorable results of this study suggest that the high acquisition costs of rituximab biosimilars may be offset by its effectiveness and provide economic evidence in support of its listing on the Pharmaceutical Benefits Scheme for pemphigus vulgaris.

Biologics in autoimmune bullous diseases: Current scenario

Autoimmune bullous diseases can be intraepidermal (pemphigus group of disorders) or subepidermal (pemphigoid group of disorders). The treatment of these disorders chiefly comprises corticosteroids and immunosuppressant adjuvants like azathioprine and mycophenolate mofetil. Autoantibodies are the main mediators of these diseases. Rituximab, a chimeric anti-CD20 monoclonal antibody targeting B-cells, has emerged as an excellent treatment option for refractory pemphigus vulgaris in the last decade. Since then, many new biologics have been proposed/explored for managing autoimmune bullous diseases. These hold potential for greater efficacy and lesser adverse effects than conventional immunosuppressants. In this review, we discuss the role of various biologics in the treatment of autoimmune bullous diseases, followed by a brief discussion on the drawbacks to their use and new developments in this area.

Clinical and biological activity of rituximab in the treatment of pemphigus

B-cells are major effector cells in autoimmunity since they differentiate into plasmocytes that produce pathogenic auto-antibody such as anti-desmoglein antibodies in pemphigus patients. Major advances were obtained using whole B-cell depleting therapies including anti-CD20 antibodies in refractory pemphigus patients that lead to rituximab approval in pemphigus patients in EU and USA. This review summarizes the data supporting the efficacy of rituximab in pemphigus and provides an overview of the reported immunological changes underlying its therapeutic action. Short and long-term remission in pemphigus is explained by the removal of autoreactive B-cells involved in the production of pathogenic IgG auto-antibodies and by enhancement of the appearance of regulatory B-cells that could maintain long term immune tolerance.

National trends in incidence, mortality, hospitalizations, and expenditures for pemphigus in Taiwan

BACKGROUND

Data on trends in epidemiological characteristics and economic burden of pemphigus are scarce.

OBJECTIVE

To describe national trends in pemphigus' incidence, mortality, hospitalizations, and expenditures between 2003 and 2015 in Taiwan.

METHODS

This nationwide study used the Taiwan National Health Insurance Research Database to identify pemphigus patients from 2003 to 2015. Annual incidence, prevalence, healthcare utilization, and expenditure trends were calculated and analyzed.

RESULTS

Pemphigus' incidence increased significantly from 3.19 to 4.70 per million person-years in 2003-2010 but fluctuated in 2011-2015. Pemphigus patients had higher mortality and care costs. Medical utilization and expenditure declined for pemphigus inpatients and outpatients. Systemic corticosteroid use decreased, but mortality remained stable.

CONCLUSION

The health expense reduction for pemphigus was mainly attributed to decreased utilization, length of stay, and inpatient costs. The persistently elevated mortality rate highlights an unmet need in pemphigus therapy.

Disease burden of patients with pemphigus from a societal perspective

Introduction: Cost-of-illness studies are widely used for healthcare decision-making; however, no such study is available in pemphigus from the societal perspective. The purpose of this analysis was to estimate annual cost-of-illness per patient with pemphigus from a societal perspective. Areas covered: Between 2014 and 2017, a multicenter, cross-sectional study was carried out. Consecutive pemphigus patients aged ≥18 years were recruited at all four university dermatology departments in Hungary. Direct and indirect costs were calculated, including costs for treatments, outpatient visits, hospital admissions, informal care, travel costs and productivity loss. Generalized linear model was used to analyze predictors of costs. Atotal of 109 patients with pemphigus enrolled with amean age of 57.1 (SD 14.8) years. Total cost per pemphigus patient was €3,995 (SD €7,526) peryear, with productivity loss (58%) and informal care (19%) accounting for the majority. Annual means of 189 and 41 working hours were lost due to absence from work and reduced productivity, respectively. Younger age and pemphigus vulgaris were associated with higher costs (p < 0.05). Expert opinion: This is the first cost-of-illness study applying the societal perspective in pemphigus. Our results indicate a substantial economic burden on society, mainly driven by productivity loss and informal care.

Rituximab in autoimmune pemphigoid diseases: Indications, optimized regimens, and practice gaps

Rituximab is a monoclonal antibody targeting CD20 on B cells with proven efficacy for pemphigus vulgaris, now an FDA-approved indication. Other autoimmune bullous diseases can be challenging to treat and have significant associated morbidity and mortality, but data supporting the use of rituximab in pemphigoid group diseases remain limited. Although rituximab demonstrates efficacy for clinical improvement and remission in pemphigoid, concern for adverse events may also limit the use of this medication. We review the current evidence fo rthe use of rituximab in pemphigoid diseases, pertinent dosing schedules and laboratory monitoring, and the associated common and rare adverse events. Review of the literature to date not only supports consideration of rituximab for treatment of refractory pemphigoid group diseases but also reflects tolerability and an acceptable safety profile.

Targeted Therapies for Autoimmune Bullous Diseases: Current Status

Autoimmune bullous skin disorders are rare but meaningful chronic inflammatory diseases, many of which had a poor or devastating prognosis prior to the advent of immunosuppressive drugs such as systemic corticosteroids, which down-regulate the immune pathogenesis in these disorders. Glucocorticoids and adjuvant immunosuppressive drugs have been of major benefit for the fast control of most of these disorders, but their long-term use is limited by major side effects such as blood cytopenia, osteoporosis, diabetes mellitus, hypertension, and gastrointestinal ulcers. In recent years, major efforts were made to identify key elements in the pathogenesis of autoimmune bullous disorders, leading to the identification of their autoantigens, which are mainly located in desmosomes (pemphigus) and the basement membrane zone (pemphigoids). In the majority of cases, immunoglobulin G, and to a lesser extent, immunoglobulin A autoantibodies directed against distinct cutaneous adhesion molecules are directly responsible for the loss of cell-cell and cell-basement membrane adhesion, which is clinically related to the formation of blisters and/or erosions of the skin and mucous membranes. We describe and discuss novel therapeutic strategies that directly interfere with the production and regulation of pathogenic autoantibodies (rituximab), their catabolism (intravenous immunoglobulins), and their presence in the circulation and extravascular tissues such as the skin (immunoadsorption), leading to a significant amelioration of disease. Moreover, we show that these novel therapies have pleiotropic effects on various proinflammatory cells and cytokines. Recent studies in bullous pemphigoid suggest that targeting of immunoglobulin E autoantibodies (omalizumab) may be also beneficial. In summary, the introduction of targeted therapies in pemphigus and pemphigoid holds major promise because of the high efficacy and fewer side effects compared with conventional global immunosuppressive therapy.

Shifting Focus in the Therapeutics of Immunobullous Disease

Therapeutics of autoimmune bullous disease has seen a major shift of focus from more global immunosuppression to targeted immunotherapy. Anti CD 20 monoclonal antibody Rituximab revolutionized the therapeutics of autoimmune bullous disease particularly pemphigus. Though it is still being practiced off-label, evidences in the form of RCT and meta analysis are now available. Other novel anti CD 20 monoclonal antibodies like ofatumumab, veltuzumab, and ocrelizumab, tositumomab or obinutuzumab/GA101 may add to the therapeutic options in coming days. Beyond anti CD 20 monoclonal antibodies other options that show promise at least in select scenario are omalizumab, TNF inhibitors plasmapheresis and intravenous immunoglobulin. The present article will discuss the role of rituximab and other newer therapeutics in the treatment of autoimmune blistering disease, especially pemphigus and suggests their positions in the therapeutic ladder.

First-line rituximab combined with short-term prednisone versus prednisone alone for the treatment of pemphigus (Ritux 3): a prospective, multicentre, parallel-group, open-label randomised trial

BACKGROUND

High doses of corticosteroids are considered the standard treatment for pemphigus. Because long-term corticosteroid treatment can cause severe and even life-threatening side-effects in patients with this disease, we assessed whether first-line use of rituximab as adjuvant therapy could improve the proportion of patients achieving complete remission off-therapy, compared with corticosteroid treatment alone, while decreasing treatment side-effects of corticosteroids.

METHODS

We did a prospective, multicentre, parallel-group, open-label, randomised trial in 25 dermatology hospital departments in France (Ritux 3). Eligible participants were patients with newly diagnosed pemphigus aged 18-80 years being treated for the first time (not at the time of a relapse). We randomly assigned participants (1:1) to receive either oral prednisone alone, 1·0 or 1·5 mg/kg per day tapered over 12 or 18 months (prednisone alone group), or 1000 mg of intravenous rituximab on days 0 and 14, and 500 mg at months 12 and 18, combined with a short-term prednisone regimen, 0·5 or 1·0 mg/kg per day tapered over 3 or 6 months (rituximab plus short-term prednisone group). Follow-up was for 3 years (study visits were scheduled weekly during the first month of the study, then monthly until month 24, then an additional visit at month 36). Treatment was assigned through central computer-generated randomisation, with stratification according to disease-severity (severe or moderate, based on Harman's criteria). The primary endpoint was the proportion of patients who achieved complete remission off-therapy at month 24 (intention-to-treat analysis). This study is registered with ClinicalTrials.gov, number NCT00784589.

FINDINGS

Between May 10, 2010, and Dec 7, 2012, we enrolled 91 patients and randomly assigned 90 to treatment (90 were analysed; 1 patient withdrew consent before the random assignment). At month 24, 41 (89%) of 46 patients assigned to rituximab plus short-term prednisone were in complete remission off-therapy versus 15 (34%) of 44 assigned to prednisone alone (absolute difference 55 percentage points, 95% CI 38·4-71·7; p<0·0001. This difference corresponded to a relative risk of success of 2·61 (95% CI 1·71-3·99, p<0·0001), corresponding to 1·82 patients (95% CI 1·39-2·60) who would need to be treated with rituximab plus prednisone (rather than prednisone alone) for one additional success. No patient died during the study. More severe adverse events of grade 3-4 were reported in the prednisone-alone group (53 events in 29 patients; mean 1·20 [SD 1·25]) than in the rituximab plus prednisone group (27 events in 16 patients; mean 0·59 [1·15]; p=0·0021). The most common of these events in both groups were diabetes and endocrine disorder (11 [21%] with prednisone alone vs six [22%] with rituximab plus prednisone), myopathy (ten [19%] vs three [11%]), and bone disorders (five [9%] vs five [19%]).

INTERPRETATION

Data from our trial suggest that first-line use of rituximab plus short-term prednisone for patients with pemphigus is more effective than using prednisone alone, with fewer adverse events.

FUNDING

French Ministry of Health, French Society of Dermatology, Roche.

Future therapies for pemphigus vulgaris: Rituximab and beyond

The conventional treatment for patients with pemphigus vulgaris (PV) centers on global immunosuppression, such as the use of steroids and other immunosuppressive drugs, to decrease titers of antidesmoglein autoantibodies responsible for the acantholytic blisters. Global immunosuppressants, however, cause serious side effects. The emergence of anti-CD20 biologic medications, such as rituximab, as an adjunct to conventional therapy has shifted the focus to targeted destruction of autoimmune B cells. Next-generation biologic medications with improved modes of delivery, pharmacology, and side effect profiles are constantly being developed, adding to the diversity of options for PV treatment. We review promising monoclonal antibodies, including veltuzumab, obinutuzumab (GA-101), ofatumumab, ocaratuzumab (AME-133v), PRO131921, and belimumab.