Anti-CD20 monoclonal antibody (rituximab) for refractory autoimmune thrombocytopenia in a girl with systemic lupus erythematosus

Rituximab alleviates pediatric systemic lupus erythematosus associated refractory immune thrombocytopenia: a case-based review

A complication of pediatric systemic lupus erythematosus (pSLE) is immune thrombocytopenia (ITP). Although corticosteroids and immunoglobulins are frequently used as preliminary treatments, some patients do not respond to them. Rituximab has been reported to be safe and effective in the treatment of pSLE complicated with refractory ITP. Research is currently underway to determine the optimal rituximab dose for these individuals. We report a case of a child with SLE-associated ITP (SLE-ITP) who was successfully treated with rituximab. Rituximab is likely the most viable therapeutic option for refractory SLE-ITP. Furthermore, a comprehensive review of the relevant literature was performed and a concise overview of the pathogenesis and available treatment modalities for pediatric patients diagnosed with SLE and concurrent ITP was provided.

Theory, targets and therapy in systemic lupus erythematosus

The treatment of systemic lupus erythematosus (SLE) has been refined over the years, with the recognition that a fine balance lies between aggressive and prompt therapy and attendant complications brought upon by immunosuppressive therapy itself. However, there has been limited change to the repertoire of drugs available to treat this challenging disease. The current standard therapy for severe manifestations of SLE includes the use of high-dose corticosteroids and cytotoxic agents such as cyclophosphamide (CYC), which have been associated with an increased risk of serious and opportunistic infections. The need for safer, more targeted therapies has been recognized and now, with the exponential increase in the understanding of immunopathogenic mechanisms in SLE, the way has been paved for the development of biologic or targeted therapies in SLE. Although the potential immunosuppression, long-term safety issues and cost-effectiveness remain unclear. These targeted therapies may range from small molecules that specifically inhibit inflammatory processes at an intracellular, cell-cell or cell-matrix level to monoclonal antibodies, soluble receptors or natural antagonists that interfere with cytokine function, cellular activation and inflammatory gene transcription.

Rituximab therapy has a rapid and durable response for refractory cytopenia in childhood-onset systemic lupus erythematosus

Objectives

Autoimmune thrombocytopenia (AITP) and hemolytic anemia (AIHA) are common in childhood-onset systemic lupus erythematosus (cSLE) and may be refractory to conventional therapies. Our objectives were to: (a) examine our experience; (b) determine the rate and durability of response to rituximab; and (c) evaluate its safety in our cSLE population with refractory cytopenias.

Methods

We performed a single-center retrospective cohort study of cSLE patients with refractory AITP or AIHA treated with rituximab between 2003 and 2012. Outcomes included the time to complete clinical response, time to B-cell depletion, duration of response and time to flare. Adverse events were also analyzed.

Results

Twenty-four (6%) of 394 cSLE patients received rituximab for refractory cytopenia. The indication was AITP in 16 (67%), AIHA in five (21%) and both in three (13%) patients. The median (interquartile range (IQR)) time from cytopenia onset to rituximab therapy was 16 (7–27) months for AITP and 10 (2–29) months for AIHA. Complete response following the first course of rituximab occurred at a median (IQR) of 48 (14–103) days, only one patient failed to respond. Five (21%) patients had one or more flare episodes at 22 (15–27) months. Infusion reactions were rare and one infection with herpes zoster required hospitalization in the first 12 months. Three of four patients with low IgG levels prior to the first rituximab course developed persistent hypogammaglobulinemia, and three patients have required intravenous immunoglobulin replacement.

Conclusion

Rituximab appears to be a well-tolerated, safe and long-lasting therapy for cSLE patients with refractory AITP and/or AIHA. Caution should be exercised when considering rituximab for patients with preexisting hypogammaglobulinemia.

Indications for use and safety of rituximab in childhood renal diseases

Rituximab was initially developed for the treatment of patients with B cell lymphoma but has during the last decade proven to be quite effective in treating a range of kidney diseases including lupus nephritis, nephrotic syndrome, and also in different situations before and after a renal transplant. We will here review the scientific basis for the use of rituximab in children with renal diseases and give recommendations both regarding its clinical use and need for further research.

Rituximab: beyond simple B cell depletion

Rituximab, a chimeric anti-CD20 monoclonal antibody, has a proven track record for over a decade in the treatment of lymphomas, where it has been used to eradicate malignant lymphocytes. In appreciation of the putative role of B cells, especially with respect to autoantibody production, in the pathogenesis of autoimmune diseases, successful trials of B-cell depletion therapy in RA, SLE, and other autoimmune diseases have been carried out. In these trials, clinical benefit has generally correlated with the extent and duration of B-cell depletion, but at times imperfectly, and autoantibody reduction only selectively. Additional mechanisms whereby rituximab may assert its clinical benefit in autoimmune diseases have been examined including a look at B-cell functions as T-cell modulator and antigen-presenting cell, T-regulatory cell behavior, NK cell activity, and macrophage activities in immune inflammation. The available data on rituximab's action in autoimmune diseases is reviewed.

B-cell depletion for autoimmune thrombocytopenia and autoimmune hemolytic anemia in pediatric systemic lupus erythematosus

OBJECTIVES

Our goal was to determine long-term efficacy and safety of B-cell-depletion therapy for children with autoimmune thrombocytopenia and autoimmune hemolytic anemia in pediatric systemic lupus erythematosus.

PATIENTS AND METHODS

A retrospective, single-center cohort study was conducted including all patients with pediatric systemic lupus erythematosus who were diagnosed with autoimmune thrombocytopenia and/or autoimmune hemolytic anemia and treated with rituximab. Treatment efficacy and safety parameters were monitored and recorded.

RESULTS

Nine patients with pediatric systemic lupus erythematosus were included in the study: 5 had autoimmune thrombocytopenia, 3 had autoimmune hemolytic anemia, and 1 had both. There were 5 female and 4 male patients; median age at diagnosis of pediatric systemic lupus erythematosus was 14 years (range: 8-16 years); and median pediatric systemic lupus erythematosus disease duration to time of rituximab treatment was 6 months (range: 2-30 months). Complete response was achieved in all 6 children with autoimmune thrombocytopenia (median time to complete response: 2 weeks [range: 1-12 weeks]). Two patients' conditions flared at 48 and 68 weeks, respectively, and were re-treated. The remaining 4 patients continued to be in remission at 24, 32, 36, and 88 weeks, respectively. All 4 children with autoimmune hemolytic anemia achieved complete response at a median time of 4 weeks (range: 4-32 weeks). All patients remained in complete response at 24, 44, 84, and 100 weeks of follow-up. Complete B-cell depletion was seen in all children after rituximab treatment. No serious infections occurred, but 1 patient had an infusion reaction.

CONCLUSIONS

Preliminary evidence suggests that B-cell-depletion therapy with rituximab is an efficacious and safe treatment for autoimmune thrombocytopenia and autoimmune hemolytic anemia in pediatric systemic lupus erythematosus. Despite the prolonged effect on B-cell numbers and function, no serious infections were observed.

Rituximab treatment for chronic refractory idiopathic thrombocytopenic purpura

Idiopathic thrombocytopenic purpura (ITP) is characterized by mucocutaneous bleeding and a low platelet count caused by increased autoantibodies against self-antigens and T-cell mediated cytotoxicity. About 10-30% patients with ITP will become refractory ITP. Most of them will become refractory to corticosteroids and splenectomy, as well as other available agents such as intravenous immunoglobulins, danazol, or chemotherapy. B cells not only are the passive producers of immunoglobulins, but also play an important immunoregulatory role in pathophysiology of ITP. Rituximab, a chimeric anti-CD20 monoclonal antibody that specifically targets the CD20 molecule on the B-cell surface, is useful in the treatment of ITP through B cells depletion. Rituximab has multiple mechanisms of inducing cytotoxicity in vivo, including antibody-dependent cell-mediated cytotoxicity (ADCC), complement-dependent cytotoxicity (CDC), direct apoptosis signaling, and possible vaccine effects. In most clinical reports, rituximab was given as an intravenous infusion at a dose of 375 mg/m(2) weekly for four doses. A total complete response (CR) of 33.2% and a total response of 52.9% were reported. Most results found that no clinical or laboratory parameters could predict treatment outcome. Though the infusion-related side effects of rituximab were common in ITP, it was well tolerated with rare severe side effects. In general, rituximab appears to be a promising immunotherapeutic agent for the treatment of refractory ITP. More controlled clinical trials are necessary to evaluate both the efficacy and long-term safety of the drug.

Update on therapeutic monoclonal antibodies

Monoclonal antibodies are among the most important class of drugs introduced into the therapeutic armamentarium since the introduction of antimicrobials in the 1930s. The first therapeutic monoclonal antibody, the anti T-cell monoclonal antibody OKT4, was licensed in 1986. Since then, 18 additional antibodies have been licensed in the US, with many more in the pipeline. Before 1986, many monoclonal antibodies were available for laboratory studies, notably to identify specific cells in the blood and tissues. This is best illustrated by the cluster designation (CD) system for antigens present on hematopoietic cells, now numbering over 200.

Histopathologic and clinical outcome of rituximab treatment in patients with cyclophosphamide-resistant proliferative lupus nephritis

OBJECTIVE

Rituximab is a monoclonal antibody directed against the CD20 marker of B cells. Because of its ability to deplete B lymphocytes, it has been suggested that the drug could be of benefit in B cell-dependent diseases, including systemic lupus erythematosus (SLE). The purpose of this study was to investigate the histopathologic and clinical effects of combination treatment with rituximab and cyclophosphamide (CYC) in patients with CYC-resistant proliferative lupus nephritis.

METHODS

Seven female patients with proliferative lupus nephritis were treated with rituximab in combination with CYC. Renal biopsies were performed before treatment and during followup. SLE activity was evaluated by the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) and the British Isles Lupus Assessment Group index. In 6 of the 7 patients, immunostaining of lymphocyte subpopulations in the renal tissue was performed before treatment and during followup.

RESULTS

At 6 months of followup, significant clinical improvement was noted, with a reduction in SLEDAI scores (from a mean of 15 to 3), anti-double-stranded DNA antibody levels (from a mean of 174 IU/ml to 56 IU/ml), and anti-C1q antibody levels (from a mean of 35 units/ml to 22 units/ml). On repeat renal biopsy, improvement in the histopathologic class of nephritis occurred in a majority of patients, and a decrease in the renal activity index was noted (from 6 to 3). A reduction in the number of CD3, CD4, and CD20 cells in the renal interstitium was noted in 50% of the patients on repeat biopsy.

CONCLUSION

At 6 months of followup, all patients had responded both clinically and histopathologically to combination therapy. For patients with proliferative lupus nephritis who fail to respond to conventional immunosuppressive therapy including CYC, combined treatment with rituximab and CYC may constitute a new treatment option.

Beneficial effects of rituximab therapy for systemic lupus erythematosus

We report an 11-yr-old girl with systemic lupus erythematosus (SLE) with recurrent flares of skin and systemic manifestations, which were poorly controlled with conventional therapy. Treatment with rituximab, a monoclonal antibody against CD20, was associated with remission of symptoms and a steroid sparing effect that persisted for more than 9 months. Therapy with rituximab appears promising in subjects with SLE.

Update on the treatment of lupus nephritis

Lupus nephritis (LN) is a major cause of morbidity and mortality in patients with systemic lupus erythematosus. Although the use of aggressive immunosuppression has improved both patient and renal survival over the past several decades, the optimal treatment of LN remains challenging. Improved outcomes have come at the expense of significant adverse effects owing to therapy. Moreover with long-term survival, the chronic adverse effects of effective therapies including risk of malignancy, atherosclerosis, infertility, and bone disease all become more important. Finally, some patients fail to achieve remission with standard cytotoxic therapy and others relapse when therapy is reduced. For these reasons, recent clinical trials have attempted to define alternate treatment protocols that appear to be efficacious in achieving and maintaining remission, but with less toxicity than standard regimens. This paper discusses established and newer treatment options for patients with proliferative and membranous LN, with an emphasis on the results of these recent clinical trials. We also review the experimental and human data regarding some of the novel targeted forms of therapy that are under investigation and in different phases of clinical trials.

Rituximab therapy for childhood-onset systemic lupus erythematosus

OBJECTIVE

To describe the safety and efficacy of rituximab in the treatment of childhood-onset systemic lupus erythematosus (SLE).

STUDY DESIGN

We conducted a French multicenter retrospective study of childhood-onset SLE treated with rituximab.

RESULTS

Eleven girls with severe SLE, including 8 girls with class IV or V lupus nephritis, 2 girls with severe autoimmune cytopenia, and 1 girl with antiprothrombin antibody with severe hemorrhage, were treated with rituximab. The mean age at onset of rituximab treatment was 13.9 years. Patients received 2 to 12 intravenous infusions of rituximab (350-450 mg/m2/infusion), with corticosteroids. Six patients also received different standard immunosuppressive agents, including Cyclophosphamide (2 patients). Remission was achieved in 6 of 8 patients with lupus nephritis and in the 2 patients with autoimmune cytopenia. Steroid therapy was tapered in 5 patients who responded to treatment, and low-dose prednisone treatment was maintained in 1 patient. The mean follow-up period was 13.2 months (range, 6-26 months), and remission lasted in all who patients who responded to treatment, except 1 patient who was successfully retreated with a second course of rituximab. Anti-double-stranded DNA antibody levels decreased in 6 of 11 patients, and anticardiolipin antibody levels decreased in 3 of 4 patients. Severe adverse events developed in 5 patients. Effective depletion of peripheral blood B cells was observed in 7 of 8 patients who were examined, and this paralleled the remission.

CONCLUSION

Rituximab may be an effective co-therapy; however, further investigations are required because severe adverse events occurred in 45% of the patients in this study.

Emergence of targeted immune therapies for systemic lupus

Systemic lupus erythematosus (SLE) is a prototypical autoimmune disease, characterised by flares of rampant inflammation that can threaten, in an unpredictable manner, almost any organ in the body. Current standard of care is largely empiric, involving the use of corticosteroids and toxic immune suppressive agents that are widely acknowledged to have unacceptable side effects for long-term use. Recently, there have been significant advances in understanding the nature of some fundamental immune imbalances underlying the complicated clinical manifestations of SLE. Nevertheless attempts to develop and test more targeted, and potentially safer immune-modulating drugs for lupus have encountered significant obstacles, due to the lack of validated biological markers for disease flare and remission, and difficulties in the clinical assessment of the heterogeneous patients. In support of renewed interest in drug development for lupus, large collaborative groups have formed, and efforts are underway to develop objective biomarkers for SLE as well as to improve the standardisation and reproducibility of clinical outcome measures in multi-centre trials.

Rituximab: A promising therapy in systemic lupus erythematosus

Several trials of new immunologic agents in systemic lupus erythematosus (SLE) have recently been undertaken. Rituximab, a chimeric antibody directed against CD20 on B lymphocytes, has emerged as a promising therapy. Based upon preliminary data, clinical efficacy of rituximab has been documented in both pediatric and adult-onset SLE patients. The specific manifestations reported to be beneficially affected include lupus nephritis, arthralgia/arthritis, serositis, cutaneous vasculitis, mucositis, rashes, fatigue and neurologic symptoms. Although rituximab's mechanisms of action are incompletely understood, the effects of rituximab are likely mediated by antibody-dependent cell-mediated cytotoxicity and the induction of apoptosis. The resultant repopulation of B cells, alteration of abnormal B cell homeostasis and down-regulation of co-stimulatory molecules on both B and T cells all likely contribute to clinical efficacy. Good tolerability of rituximab is reported with rare serious side effects. The positive response to rituximab verifies a central role for B cells in SLE. This article highlights the clinical experience of rituximab therapy in both pediatric and adult-onset SLE. These data suggest a promising role for rituximab in the treatment of SLE. Further controlled trials and long-term outcome studies are imperative to further define its clinical application and to improve the care of patients.

Rituximab anti-B-cell therapy in systemic lupus erythematosus: pointing to the future

PURPOSE OF REVIEW

To discuss the clinical effects and the immunologic consequences of transient B-cell depletion using the anti-CD20 monoclonal antibody rituximab in systemic lupus erythematosus.

RECENT FINDINGS

A total of 100 rituximab-treated patients with severe disease, refractory to major immunosuppressive treatment, have been reported so far. Within a median follow-up period of 12 months rituximab was well tolerated, which is compatible with the experience accumulated from its use in more than 500 000 lymphoma patients. About 80% of patients achieved marked and rapid reductions in global disease activity. Because of the clinical heterogeneity, dosing differences, and concomitant treatments, including cyclophosphamide in 35% of patients, a proper evaluation of the clinical efficacy or rituximab is difficult. Variable degrees of clinical benefit have been reported for all clinical systemic lupus erythematosus manifestations, including active proliferative nephritis. Whereas 4-weekly infusions of 375 mg/m of rituximab result in complete B-cell depletion lasting most often from 3 to 8 months, a prolonged depletion does not always correlate with a more favorable clinical response. Total immunoglobulin levels and protective antibodies are preserved, but anti-dsDNA antibody titers decrease, often independently of the clinical response.

SUMMARY

The findings reviewed point to a growing optimism for targeting B cells in the treatment of systemic lupus erythematosus; therefore double-blind studies comparing rituximab with existing immunosuppressive therapies are needed. Moreover, careful assessments of the effects of transient B-cell depletion on distinct autoimmune pathogenetic processes will enable optimization of therapeutic single or combined therapeutic schemes.

The management of pediatric systemic lupus erythematosus

Most children and adolescents with systemic lupus erythematosus (SLE) now survive into adulthood, leading the pediatric rheumatology community to focus on preventing long-term complications of SLE, including atherosclerosis, obesity, and osteoporosis, and their treatment. Unfortunately, because of the paucity of data in pediatric SLE, little is known about epidemiology, long-term outcome, and optimal treatment. Most research focuses on adults with SLE, but pediatric SLE differs significantly from adult SLE in many aspects, including disease expression, approaches to pharmacologic intervention, management of treatment toxicity, and psychosocial issues. Children and adolescents with SLE require specialized, multidisciplinary care. Treatment can be optimized by early recognition of disease flares and complications, minimizing medication toxicity, educating families about prevention, promoting school performance, addressing concerns about reproductive health, and negotiating the transition to adult-centered medical care. Developmentally appropriate concerns about pain, appearance, and peers often affect treatment adherence and must be addressed by the health-care team. Research in pediatric SLE is desperately needed and provides a unique opportunity to understand how developmental immunology and the hormonal changes associated with puberty affect the pathophysiology of SLE.

Autoimmune mechanisms in children with systemic lupus erythematosus

Although the pathogenesis of SLE remains poorly understood, there is consensus that it involves a combination of genetic, hormonal, and environmental factors. New technologies applied to genomic and gene expression studies have revealed novel gene mutations and cytokine alterations in this disease. Recently, advances in monoclonal antibodies and recombinant DNA technology have resulted in the development of new drugs to arrest disease progression and restore physiologic immune responses without major side effects. Clinical trials to test several of these novel therapies are currently underway.

Systemic lupus erythematosus

Systemic lupus erythematosus in children and adolescents is a multisystem autoimmune disease with a great variability in disease presentation and course. This article summarizes available epidemiologic data, clinical patterns, approaches to investigation and treatment, and recent outcome data.

B lymphocyte depletion therapy in children with refractory systemic lupus erythematosus

OBJECTIVE

To determine the safety and efficacy of B lymphocyte depletion therapy in patients with refractory childhood-onset systemic lupus erythematosus (SLE).

METHODS

Seven patients (4 of whom were female), ages 7.7-16.1 years (median 14.8 years) with active SLE that was resistant to standard immunosuppressive agents were treated with B cell depletion. During a 2-week period, patients received two 750-mg/m2 intravenous infusions of rituximab, with intravenous cyclophosphamide (if they had not previously received this treatment) and high-dose oral corticosteroids.

RESULTS

Patients were followed up for a median of 1.0 years, and no serious adverse effects were noted. In all patients, the clinical symptoms and signs for which rituximab therapy was initiated were improved. There was significant improvement in the British Isles Lupus Assessment Group global scores, from a median score of 22 (range 14-37) at baseline to a median score of 6 (range 4-11) at followup (P = 0.002). In 2 patients with severe multisystem and life-threatening disease unresponsive to standard therapy (including plasma exchange), renal replacement therapy was successfully withdrawn following B cell depletion therapy. These 2 patients have subsequently shown further significant improvement in renal function and proteinuria.

CONCLUSION

This open-label study demonstrates that targeted B cell depletion therapy can be a safe and efficacious addition to therapy with standard immunosuppressive agents in patients with refractory childhood SLE. The drugs used for treatment of childhood SLE need to be the most effective, least toxic agents, allowing normal growth and development.

Challenges in bringing the bench to bedside in drug development for sle

It is now widely accepted that the current standard of care for systemic lupus erythematosus (SLE) patients is inadequate. There has not been a new medication approved for this disease in thirty years. Attempts to develop and test new drugs have been ongoing since the mid-1990s, but have encountered formidable obstacles. Current models for lupus pathogenesis have provided a theoretical framework for understanding how heterogeneous genetic defects might combine in various ways to increase susceptibility to SLE in different individuals, and could have important implications for new drug development. With the current burst of drug discovery and increased public awareness of SLE, the impetus to overcome these obstacles has never been greater.

Tolerance and short term efficacy of rituximab in 43 patients with systemic autoimmune diseases

OBJECTIVE

To assess the tolerance and efficacy of rituximab in patients with various autoimmune diseases seen in daily rheumatological practice.

METHODS

866 rheumatology and internal medicine practitioners were contacted by e-mail to obtain the files of patients treated with rituximab for systemic autoimmune diseases. Patients with lymphoma were analysed if the evolution of the autoimmune disease could be evaluated.

RESULTS

In all, 43 of 49 cases could be analysed, including 14 with rheumatoid arthritis (RA), 13 with systemic lupus erythematosus (SLE), six with primary Sjogren's syndrome (pSS), five with systemic vasculitis, and five with other autoimmune diseases. Rituximab was prescribed for lymphoma in two patients with RA and two with pSS. In the 39 other cases, rituximab was given because of the refractory character of the autoimmune disease. The mean follow up period was 8.3 months (range 2 to 26). There were 11 adverse events in 10 patients and treatment had to be discontinued in six. Efficacy was observed in 30 patients (70%): RA 11, SLE 9, pSS 5, vasculitis 2, antisynthetase syndromes 2, sarcoidosis 1. The mean decrease in corticosteroid intake was 9.5 mg/d (range 0 to 50) in responders. Seven patients experienced relapse after mean 8.1 months (5 to 15). Three patients died because of refractory autoimmune disease.

CONCLUSIONS

Despite absence of marketing authorisation, rituximab is used to treat various refractory autoimmune diseases in daily rheumatological practice. This study showed good tolerance and short term clinical efficacy, with marked corticosteroid reduction in patients with SLE, pSS, vasculitis, and polymyositis.

Update on pediatric systemic lupus erythematosus

PURPOSE OF REVIEW

The purpose of this review is to provide an update on the clinical manifestations of SLE in children. Emerging clues on the pathogenesis of the disease based on recent human studies conducted both in children and adults, will also be summarized.

RECENT FINDINGS

Pediatric Rheumatologists caring for children with SLE face many challenges. As the life expectancy of these patients improves, new recognized complications such as accelerated atherosclerosis and hypertension emerge as major causes of morbidity. However, few longitudinal studies describing the long term outcome of these children, including the impact of disease and treatment on their physical and psychological development are available. Few prospective interventional studies have been carried out to assess the efficacy of established and novel treatments in the pediatric population. Recently, basic studies aimed at understanding the immune alterations underlying this disease have been performed in children. These studies indicate an important role for interferon-alpha (IFN-alpha) in the pathogenesis of this disease and reveal an overall striking homogeneity of leukocyte gene expression profiles in children and adults with SLE. The contribution of novel gene polymorphisms to disease susceptibility and the sequential breakdown of tolerance to nuclear antigens that precedes clinical manifestations in patients with SLE are among the recent studies that are helping us understand the complex SLE puzzle.

SUMMARY

SLE continues to cause significant morbidity in the pediatric age group. A better recognition of the age-specific manifestations and long-term complications of this disease is required to improve its outcome. Understanding its unique pathogenesis will hopefully lead to the development of better, more targeted and less toxic therapies.