Comparison of rituximab and intravenous immunoglobulin in the treatment of autoimmune bullous diseases: Real-life data from a single centre

BACKGROUND/AIM

Rituximab (RTX) and intravenous human immunoglobulin (IVIG) have been shown to be effective in the treatment of autoimmune bullous diseases (ABD), mainly pemphigus vulgaris (PV). The present study aimed to assess the clinical response of patients with ABD, mainly PV to RTX, IVIG and combined regimen of both. Whether adding IVIG to RTX therapy affects the achievement of complete remission off therapy (CR off), reduces time to CR off, time to steroid cessation, and decreases relapse rate was also investigated.

METHODS

Data of 33 patients with ABD [PV (93.9%)], including clinical response to treatment, steroid cessation time, time to CR off and relapse, were recruited from medical charts.

RESULTS

CR off and relapse rate, mean time to CR off and relapse was 86.7% (n = 13) vs 60.0% (n = 6) and 53.3% (n = 8) vs 40% (n = 4), 12.77 ± 9.30 vs 11.25 ± 13.40 and 24.1 ± 16.7 vs 13.0 ± 3.6 months in RTX and combination group, respectively. Older age (P = .005), younger age at the time of diagnosis (P = .004), lesser disease duration to the initiation of RTX (P = .004), lesser BMI (P = .026) and female gender (P = .037) were associated factors with CR off.

CONCLUSION

Adding IVIG to RTX did not increase CR off rates; it also did not decrease time to CR off, time to steroid cessation, relapse rates and did not increase time to relapse. Patient and disease characteristics, including age, younger age at the time of diagnosis, lesser disease duration before RTX treatment, lesser BMI and female gender, are factors associated with CR off.

Long-term experience with rituximab therapy for treatment-resistant moderate-to-severe pemphigus

BACKGROUND

Rituximab appears to be effective for treating pemphigus, although there are limited long-term data.

METHODS

This retrospective single-center study evaluated patients with conventional treatment-resistant pemphigus who received rituximab during September 2010-December 2019. The first rituximab cycle was based on the rheumatoid arthritis protocol in all patients except one patient, and additional single doses (500 mg or 1000 mg) were administered after clinical and/or serological relapse. The consensus definitions were used for complete remission off therapy, complete remission on minimal therapy, and clinical relapse. Serological relapse was defined as a progressive ≥2-fold increase in anti-desmoglein titers (vs. previous the measurement).

RESULTS

The study included 52 patients with pemphigus vulgaris and 1 patient with pemphigus foliaceus. The mean number of infusions was 5 and the average follow-up after the first infusion was 56 months. The average time to clinical and/or serological relapse was 12 months. Complete remission was achieved in 84.9% of patients, including after the first rituximab cycle in 25 patients (47.1%). Two patients died during the follow-up period.

CONCLUSION

Additional rituximab cycles may help achieve and prolong remission in patients with moderate-to-severe pemphigus resistant to conventional therapies. However, prospective trials are needed to identify the optimal dosing protocol.

Next-generation anti-CD20 monoclonal antibodies in autoimmune disease treatment

The clinical success of anti-CD20 monoclonal antibody (mAb)-mediated B cell depletion therapy has contributed to the understanding of B cells as major players in several autoimmune diseases. The first therapeutic anti-CD20 mAb, rituximab, is a murine-human chimera to which many patients develop antibodies and/or experience infusion-related reactions. A second generation of anti-CD20 mAbs has been designed to be more effective, better tolerated, and of lower immunogenicity. These include the humanized versions: ocrelizumab, obinutuzumab, and veltuzumab, and the fully human, ofatumumab. We conducted a literature search of relevant randomized clinical trials in the PubMed database and ongoing trials in Clinicaltrials.gov. Most of these trials have evaluated intravenous ocrelizumab or subcutaneous ofatumumab in rheumatoid arthritis, multiple sclerosis, or systemic lupus erythematosus. Understanding how newer anti-CD20 mAbs compare with rituximab in terms of efficacy, safety, convenience, and cost is important for guiding future management of anti-CD20 mAb therapy in autoimmune diseases.

Rituximab in pemphigus

Pemphigus is a severe autoimmune blistering disease mediated by pathogenic anti-desmoglein antibodies leading to an inter keratinocyte disjunction. Rituximab is a monoclonal antibody that binds to the CD-20 antigen of B lymphocytes, which causes B-cell depletion and a subsequent reduction in pathogenic autoantibodies. Its therapeutic role in pemphigus has been progressively growing with increasing evidence of successful outcomes. Rituximab was initially off-labeled used as an alternative in patients with recalcitrant or relapsing pemphigus and in patients with contraindications to systemic corticosteroids. Recently, a large randomized clinical trial has shown that first-line use of rituximab combined with short-term prednisone regimen was both more effective and potentially safer than a standard regimen of high doses of corticosteroids in patients with moderate to severe pemphigus.

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.

Rituximab: A Magic Bullet for Pemphigus

INTRODUCTION

Pemphigus, an autoimmune disease, was fatal before the era of corticosteroids. With the advent of steroids, mortality decreased but morbidity was present due to the side effects of high dose steroids. Newer drugs targeted at the molecular level are said to have fewer side effects and improved effectiveness.

AIM

The aim of our study was to assess the effectiveness of one such drug, Rituximab, a biological, in treating pemphigus vulgaris and to identify common adverse events.

MATERIALS AND METHODS

It was an open label prospective interventional study, conducted from September 2013 to May 2015, in the Department of Dermatology, Stanley Medical College, Chennai, Tamil Nadu, India. Twenty patients with pemphigus were included in the study. Ten were refractory to conventional therapy and 10, new cases. Patients who satisfied inclusion and exclusion criteria were included in the study after informed, written consent. Rituximab was administered according to Rheumatoid arthritis protocol. The patients were followed up as out patients after discharge, end points and adverse events were noted.

RESULTS

There were 14 females (70%) and six males (30%). The mean age of the study group was 41.35 years. The mean disease duration was 11.7 months. The mean duration of follow up being 14.25 months. After rituximab, 13 patients remained in remission for varying periods of 3-22 months. The mean duration of complete remission off- treatment with Dexamethasone Cyclophosphamide Pulse (DCP) was 3.6 months; with rituximab it was 8.8 months. Seven (35%) patients relapsed during the study of whom six had received rituximab after being refractory to conventional treatment. Patients who relapsed had higher mean disease duration (21 months) than the remission group (6.384 months). Two patients (10%) developed immediate adverse events. Six patients (30%) developed late adverse events the commonest being reactivation of herpes labialis.

CONCLUSION

Rituximab was effective in treating pemphigus vulgaris, was significantly better than conventional treatment, decreased the need for additional steroids and other immunosuppressants and induced prolonged remission. Rituximab was more effective when given early in the disease process. Further studies may highlight the need for additional cycles of rituximab to maintain sustained remission.

The emerging role of rituximab in autoimmune blistering diseases

Rituximab is a chimeric monoclonal antibody that selectively binds to the CD20 molecule on B cells, resulting in their lysis. In autoimmune blistering diseases, the auto-antibody-producing B cells are destroyed and auto-antibody levels are reduced or eliminated. In the majority of patients, rituximab produces rapid clinical response and early resolution. In part, this accounts for the increased use of rituximab. Rituximab does not distinguish normal from pathologic B cells. Hence, shortly after its use, B-cell levels are zero and remain so for several months. In most patients, the use of systemic corticosteroids and immunosuppressive agents are continued after rituximab therapy, while their dosages are significantly decreased. In the majority of patients rituximab is used according to the protocol used in treating lymphoma patients or patients with rheumatoid arthritis. Approximately 50% of patients experience a relapse, requiring additional therapy. Serious adverse events and fatal outcomes have been reported, although their incidence is less than that observed with conventional therapy. Nonetheless, the causes, i.e. infections and septicemia, are similar. Several gaps exist in our understanding of how to optimally benefit from the use of this valuable biological agent. Future studies need to be targeted in designing and implanting protocols that maximize the benefit of rituximab and result in producing sustained prolonged remissions with minimal adverse events and a high quality of life.

Severe multi-resistant pemphigus vulgaris: prolonged remission with a single cycle of rituximab

Pemphigus vulgaris is an autoimmune bullous disease whose therapy is based on systemic corticosteroids, with or without immunosuppressants. Rituximab is a chimeric monoclonal antibody of the IgG class, directed at a specific CD20 B cell surface antigen, used in pemphigus vulgaris empirically since 2002, with success in 90% of the cases and long periods of remission. Male patient, 33 years old, diagnosed with pemphigus vulgaris, confirmed by histopathology and direct immunofluorescence. He was treated for seven months with numerous treatments, including immunosuppressive drugs, with an unsatisfactory response, until he had complete remission with the use of rituximab. During a 34-month follow-up period, the patient presented a slight clinical relapse, which was successfully controlled with prednisone in a daily dose of 120mg, soon reduced to 20mg.

Refractory pemphigus foliaceus and Behçet's disease successfully treated with tocilizumab

Pemphigus foliaceus (PF) and Behçet's disease (BD) are immune-mediated conditions which are usually treated with corticosteroids, immunosuppressants, and, when refractory, with biologic agents. In both diseases, interleukin (IL)-6 serum levels are increased driving the immune-mediated inflammatory process. Tocilizumab is a humanized monoclonal antibody, targeting IL6-receptor, used in the treatment of rheumatoid arthritis. Besides the current indication, it has been recently administered to patients with refractory immune inflammatory diseases as an off-label treatment. Here, we report the case of a woman affected with PF and BD, who did not respond to corticosteroids, immunosuppressants, and biologic agents including adalimumab, anakinra, and infliximab. A complete, long-lasting, clinical, and serological remission was achieved only with tocilizumab. To the best of our knowledge, the association between PF and BD has never been reported. Moreover, only two cases of BD and no cases of PF treated with tocilizumab have been described to date. A literature review on the use of biologic agents on patients with PF and BD was also carried out.

Rituximab in the treatment of pemphigus vulgaris

INTRODUCTION

Rituximab is increasingly used in patients with pemphigus vulgaris (PV) who are nonresponders to conventional therapy.

METHODS

A PubMed search was conducted using the words pemphigus vulgaris and rituximab therapy from papers published between 2000 and 2012. Two protocols were used. In the lymphoma protocol, patients received four weekly infusions of rituximab (dose 375 mg/m(2)). The rheumatoid arthritis (RA) protocol consisted of two infusions of 1,000 mg each 15 days apart. The variables recorded from each study included clinical remission off or on therapy, relapse rate, incidence of serious adverse events, concomitant therapies, duration of follow-up, and when available, levels of B cells and autoantibodies.

RESULTS

Forty-two studies were found, which reported 272 patients; 180 were treated by the lymphoma protocol and 92 by the RA protocol. Both protocols were effective in treating recalcitrant PV. The lymphoma protocol had a lower response rate, relapse rate and serious infections, but higher mortality, and there were nonresponders. The RA protocol produced a higher response rate, relapse rate, number of infections, but lower mortality rate, and lacked nonresponders. The cumulative follow-up for patients treated with the lymphoma protocol was 15.44 months (range 1-41) and 21.04 months (range 8.35-29) for the RA protocol. A major concern in both protocols was the high infection rates, some of which were fatal. A different protocol using a combination of rituximab with intravenous immunoglobulin in a defined manner with a definitive endpoint, used in a limited cohort of patients, showed promising results.

CONCLUSION

Neither protocol produced a sustained clinical remission and both required continued systemic therapy. Before initiation of treatment, physicians should have a specific goal and endpoint and be aware of its potential side effects and lack of information on its long-term effects. Patients should be carefully monitored during and after therapy.