The efficacy and safety of rituximab in refractory pemphigus: a review of case reports

Rituximab is a chimeric murine-human monoclonal antibody that targets the CD20 antigen found on B cells and results in rapid depletion of this cell population. It is indicated for patients with relapsed or refractory, low-grade or follicular, CD20-positive, B cell non-Hodgkin's lymphoma. In addition, rituximab has been used for many other diseases, including refractory pemphigus. In this study, 42 case reports of patients with refractory pemphigus vulgaris, pemphigus foliaceus, and paraneoplastic pemphigus treated with rituximab were reviewed for clinical efficacy and safety. Forty-one of the 42 patients had at least some improvement following the rituximab therapy, while 6 suffered infectious adverse events. Though rituximab appears to be effective in the treatment of refractory pemphigus diseases, further studies are warranted to clarify its overall safety, especially concerning the risk of infectious adverse events in this patient population.     

A review of the current use of rituximab in autoimmune diseases

Rituximab is a human/murine chimeric monoclonal antibody primarily used for treating non-Hodgkin's B-cell lymphoma. Recently it has also been used in the treatment of several autoimmune diseases. A literature review was conducted to determine the efficacy of rituximab in the treatment of some of these autoimmune diseases. Multiple mechanisms proposed for the rituximab mediated B cell depletion are also discussed. The efficacy of rituximab is well-established and it is FDA approved for treatment of Rheumatoid arthritis. In this review, data on the use of rituximab is presented from 92 studies involving 1197 patients with the following diseases: systemic lupus erythematosus, idiopathic thrombocytopenic purpura, anti-neutrophil cytoplasmic antibody associated vasculitis, Grave's disease, autoimmune hemolytic anemia, pemphigus vulgaris, hemophilia A, cold agglutinin disease, Sjogren's syndrome, graft vs. host disease, thrombotic thrombocytopenic purpura, cryoglobulinemia, IgM mediated neuropathy, multiple sclerosis, neuromyelitis optica, idiopathic membranous nephropathy, dermatomyositis, and opsoclonus myoclonus. The efficacy varies among different autoimmune diseases. The cumulative data would suggest that in the vast majority of studies in this review, RTX has a beneficial role in their treatment. While rituximab is very effective in the depletion of B cells, current research suggests it may also influence other cells of the immune system by re-establishing immune homeostasis and tolerance. The safety profile of RTX reveals that most reactions are infusion related. In patients with autoimmune diseases the incidence of serious and severe side effects is low. Systemic infection still remains a major concern and may result in death.     

Rituximab in B-cell disorders other than non-Hodgkin's lymphoma

Rituximab is a human/mouse chimeric monoclonal antibody that binds to the CD20 antigen and is expressed at all stages of B-cell development. Rituximab has demonstrated efficacy as monotherapy and in combination with chemotherapy in the treatment of both indolent and aggressive non-Hodgkin's lymphoma (NHL). Rituximab treatment results in rapid depletion of B-cells and this has led to the consideration of other B-cell disorders as candidates for rituximab therapy. Recent studies have demonstrated the efficacy of rituximab in a variety of such disorders, including chronic lymphocytic leukemia (CLL), post-transplant lymphoproliferative disorder (PTLD), Waldenstr?m's macroglobulinemia (WM), multiple myeloma (MM), idiopathic thrombocytopenic purpura (ITP), hairy-cell leukemia (HCL) and cold agglutinin disease (CAD). In patients with CLL, increasing the dose and/or frequency of rituximab treatment has given improved response rates compared with the standard dose schedule used in NHL, and combination immunochemotherapy has yielded an overall response rate of 92% (with a 60% complete response rate). Clinical trials have also demonstrated evidence of efficacy for rituximab in PTLD, WM and relapsed or refractory ITP. Efficacy of rituximab in CAD and relapsed or refractory HCL has also been demonstrated in small studies and case reports. Available data thus indicate that rituximab can be an effective therapy in a wide range of CD20+ lymphoid disorders.     

Treatment of systemic lupus erythematosus with epratuzumab

Systemic lupus erythematosus is a prototypic autoimmune disease characterized by abnormalities in the activity of B-cells and T-cells. A novel specific treatment for autoimmune diseases is B-cell depletion with monoclonal antibodies. Epratuzumab is a monoclonal antibody that targets CD22 antigen on B-cells. Initial phase II and two terminated early phase III studies suggest that treatment of systemic lupus erythematosus with this immunomodulatory agent is effective, well tolerated and significantly improves the patient's quality of life. In vitro studies and clinical trials with non-Hodgkin lymphoma patients indicate epratuzumab can potentially serve as a complementary drug in combination therapy with another inhibitor of B-cell activity, rituximab, which is a monoclonal anti-CD20 antibody.     

Using rituximab (anti-CD20 antibody) in a patient with paraneoplastic pemphigus

Paraneoplastic pemphaigus (PNP) is a rare autoimmune mucocutaneous blistering disease that is commonly associated with underlying B-cell neoplasms. There is no standard therapy for PNP. Potent immunosuppression has been the only potentially effective treatment in the setting of malignancy because there is no correlation between tumor burden and activity of disease. Two recent case reports have noted the resolution of lesions of PNP after treatment of the underlying CD20+ B-cell lymphomas with rituximab. Rituximab is an anti-CD20 antibody that has had some success in treating proliferative B-cell disorders. We report a case of PNP in the setting of B-cell lymphoma that did not respond to this novel therapy, and discuss rituximab's putative mechanism of action along with the clinical settings in which this novel therapy may prove useful in the treatment of PNP.     

Targeted B-cell depletion therapy in childhood-onset systemic lupus erythematosus: progress to date

Childhood-onset systemic lupus erythematosus (SLE) is a multisystemic autoimmune disease associated with significant morbidity and mortality with lupus nephritis being a major prognostic factor. Children with SLE tend to have more severe hematologic and renal involvement compared with adults. Although the morbidity and mortality have greatly improved over the last 20 years, recent studies show that there are still associated major risks from under treatment (with resultant severe flares of disease activity) and over treatment (with additional medication adverse effects including risks of severe infection; many of these patients have inherent abnormal complement pathways).Therapies used to treat children with SLE need to be individualized based on multiorgan involvement, severity of disease, history of disease flares, and knowledge of recent relevant clinical, hematologic, and immunologic parameters. These medications need to be the most effective treatments, allowing normal growth, development, fertility, and the avoidance of severe toxicity and future malignancies. Many toxic effects of current medications range from the well described Cushingoid features of corticosteroids to the gastrointestinal adverse effects of mycophenolate mofetil.In vitro studies have shown that rituximab causes B-cell depletion by mechanisms involving antibody-dependent cell-mediated cytotoxicity, complement-dependent cytotoxicity, and direct signaling leading to apoptosis. As the adverse effect profile of B-cell depletion with rituximab has been well described in adults and children with oncologic and other autoimmune diseases, initial pilot studies using rituximab in patients with refractory SLE have been carried out according to different protocols. Evidence to date in open studies demonstrates that targeted B-cell depletion therapy can be safe and efficacious as an addition to standard immunosuppressant agents in refractory childhood-onset and adult-onset disease. Although there are positive outcomes in using this therapy, caution is necessary with respect to minimizing the number of doses and treatments given to reduce the incidence of developing human anti-chimeric antibodies.The next phase for the clinical and research community are multicenter randomized controlled trials of rituximab in severe childhood SLE, such as a comparative trial of rituximab versus intravenous cyclophosphamide in patients both at presentation and with exacerbations of disease activity.     

Targeting B cells in SLE: the experience with rituximab treatment (anti-CD20)

B cells play a central role in the pathogenesis of SLE. Not only do they make autoantibodies, but they can provide immunoregulatory controls of T cells, dendritic cells, and other B cells, in part through cytokine production. The availability of a chimeric monoclonal antibody that targets B cells has made it possible to treat SLE by B-cell depletion. Rituximab binds to the B-cell specific antigen CD20, and depletes B cells from the peripheral blood and lymphoid tissues. A growing number of anecdotal series and case reports suggest that rituximab may provide clinical benefit in SLE with acceptable toxicity, although the variability in responses of individual patients is not yet fully understood. Two large ongoing randomized controlled trials will determine the efficacy of rituximab in SLE, both renal and extra-renal, and will inform us better about the biology of the B cell in this disease and the effects of B-cell depletion.     

Rituximab

Rituximab is a chimeric monoclonal antibody that targets the CD20 molecule on the B-cell surface. It is the first antibody of its kind to be licensed for the treatment of non-Hodgkin's lymphoma. Rituximab was found to be effective, well-tolerated and has a good safety profile, though its precise cellular effects are still not well understood. Rituximab has been shown to be of therapeutic benefit in various autoimmune diseases in which B lymphocytes play a role. This article summarizes the current literature regarding the use of rituximab in lymphoma, rheumatoid arthritis, systemic lupus erythematosus and other selected autoimmune diseases.     

Rituximab: novel B-cell depletion therapy for the treatment of rheumatoid arthritis

Significant numbers of patients with rheumatoid arthritis (RA) suffer from disease that is refractory to both conventional therapy and newer biological agents such as TNF-alpha inhibitors. These patients may respond insufficiently, lose an effective response, develop toxicity or carry contraindications to such agents. Rituximab, a chimeric monoclonal antibody against CD20 that effectively depletes B cells in peripheral blood, has been licensed for the treatment of certain haematological malignancies for almost 10 years. B cells are now known to have multiple key roles in the pathogenesis of RA. Data is now available that indicates efficacy and safety of B-cell depletion with rituximab in the treatment of RA in a variety of patient groups. The clinical outcomes from these studies, together with its safety profile, have led to rituximab being licensed for the treatment of patients with RA who have failed to obtain benefit from anti-TNF-alpha agents.     

Rituximab: novel B-cell depletion therapy for the treatment of rheumatoid arthritis

Significant numbers of patients with rheumatoid arthritis (RA) suffer from disease that is refractory to both conventional therapy and newer biological agents such as TNF-α inhibitors. These patients may respond insufficiently, lose an effective response, develop toxicity or carry contraindications to such agents. Rituximab, a chimeric monoclonal antibody against CD20 that effectively depletes B cells in peripheral blood, has been licensed for the treatment of certain haematological malignancies for almost 10 years. B cells are now known to have multiple key roles in the pathogenesis of RA. Data is now available that indicates efficacy and safety of B-cell depletion with rituximab in the treatment of RA in a variety of patient groups. The clinical outcomes from these studies, together with its safety profile, have led to rituximab being licensed for the treatment of patients with RA who have failed to obtain benefit from anti-TNF-α agents.     

Rituximab therapy for indolent non-Hodgkin's lymphoma

Indolent non-Hodgkin's lymphomas (NHLs) are essentially incurable with current treatments. Rituximab is a specific anti-CD20 chimeric monoclonal antibody against the CD20 antigen, which is stably expressed on most B-cells (from the pre-B-cell stage). Compared with chemotherapy, rituximab has an excellent tolerability profile, making it a good therapeutic option for patients with indolent NHL. In the pivotal study for rituximab, patients with relapsed or refractory indolent or follicular lymphoma (FL) had an overall response rate of 50%. There is evidence that first-line rituximab therapy may be associated with better response rates; in previously untreated FL with a low tumor burden, rituximab monotherapy has produced an overall response rate of 73%. Attempts to improve response rates to rituximab by increasing the dose or frequency of dosing showed that the addition of four extra infusions of rituximab (in addition to the standard treatment schedule) resulted in an overall response rate of 76% in patients with FL. Augmenting rituximab with cytokines is also an option for increasing response rates in patients with indolent NHL. In a trial by the Nordic Lymphoma Study Group in patients with previously untreated or first-relapse indolent NHL, who had stable disease or a partial response after four doses of rituximab, 48% of the patients treated with rituximab plus interferon-alpha2a achieved a complete response. A further option is to combine rituximab with chemotherapy. Interim analyses from the East German Study Group have shown that rituximab plus mitoxantrone, chlorambucil and prednisolone (MCP) resulted in overall response rates of 89% in patients with untreated indolent lymphoma. Rituximab is therefore an excellent treatment option both as first-line and as salvage therapy for patients with indolent NHL.     

Rituximab in the treatment of autoimmune haemolytic anaemia

Rituximab is a B-cell depleting monoclonal antibody that is gaining popularity as an effective therapy for many autoimmune cytopenias. This article systematically evaluates its therapeutic efficacy in the treatment of different types of autoimmune haemolytic anaemia. We conclude that there is sufficient evidence to recommend it as a second line therapy for warm autoimmune haemolytic anaemia (wAIHA) either as monotherapy or combined therapy. Evidence from a single randomized controlled trial suggests that it may also be more efficacious as first line therapy in combination with steroids than steroids alone. A fewer number of studies have assessed its role in cold autoimmune haemolytic anaemia (cAIHA) and cold agglutinin disease (CAD) with success rates varying from 45–66%. In the absence of alternative definitive therapy, rituximab should be considered for patients with symptomatic CAD and significant haemolysis. Case reports of its efficacy in mixed autoimmune haemolytic anaemias are available but evidence from case series or larger cohorts are nonexistent.     

Seeking approval: present and future therapies for pemphigus vulgaris

Pemphigus vulgaris is an autoimmune blistering disease of the skin and mucous membranes. Despite the potentially fatal prognosis, there are currently no FDA-approved treatments specifically for pemphigus. In 2006, the FDA designated orphan drug status to mycophenolate mofetil for the treatment of pemphigus vulgaris, indicating both federal and commercial interest in developing therapies for this devastating disease. This review focuses on pemphigus therapies that are currently in preclinical or clinical trials, as well as potential novel therapies based on recent advances in the understanding of the pathophysiology of this disease.     

Mechanism of action of rituximab

The CD20 antigen is strongly and stably expressed on cells of the B-cell lineage, but not on stem cells, and is thus an ideal target antigen for antibody therapy of B-cell malignancies. Rituximab is a human-mouse chimeric monoclonal antibody to the CD20 antigen that kills B-cells by a number of different effector mechanisms. The human IgG component of the antibody is able to bind human complement and also interact with effector cells to kill cells by antibody-dependent cell-mediated cytotoxicity. Some investigators have also shown direct effects of the antibody on human tumor cell lines expressing CD20. These effects include inhibition of proliferation, induction of apoptosis and increased sensitivity to chemotherapeutic agents, although the extent to which each of these mechanisms may contribute to the anti-tumor action of rituximab remains to be determined. Rituximab thus acts by additional mechanisms compared to conventional chemotherapeutic agents. The chimeric nature of the antibody results in minimal immunogenicity and allows repeat use. The antibody may be combined with conventional chemotherapy, with potential for increased efficacy with minimal added toxicity.     

Treatment options for refractory Wegener's granulomatosis: a role for rituximab?

Wegener's granulomatosis (WG) is a small-vessel vasculitis of unknown etiology, involving mainly the upper airways, lungs and kidneys. Organ inflammatory damage is mediated by anti-neutrophil cytoplasm antibodies, and their detection is a component of the diagnostic work-up as well as clinical signs and symptoms, and histopathological biopsy abnormalities. Conventional therapeutic regimens, such as cyclophosphamide and corticosteroids, can be used to induce and maintain disease remission. Alternatively, other cytotoxic agents (eg, methotrexate or mycophenolate mofetil), anti-TNFalpha agents (eg, infliximab or etanercept) or anti-lymphocyte antibodies (eg, rituximab) can be used. Rituximab, a mAb which targets CD20+ B-cells, is currently used in the treatment non-Hodgkin's lymphoma and rheumatoid arthritis, and is being investigated for refractory WG therapy and other autoimmune diseases.     

利妥昔单抗在血液系统临床应用研究新进展

利妥昔单抗为人鼠嵌合型单克隆抗体,已被FDA批准用于复发或难治性的CD20阳性的B细胞低度恶性或滤泡型非霍奇金淋巴瘤(NHL)的治疗.它能特异性结合B淋巴细胞表面CD20抗原,杀伤体内的B淋巴细胞.临床主要用于治疗各种一线或二线B细胞NHL,可以单独应用,亦可与化疗药物联合应用,目前还尝试用于慢性淋巴细胞白血病、多发性骨髓瘤、特发行血小板减少性紫癜等的治疗.     

Ten years of rituximab in NHL

Background: Rituximab, a chimeric mouse/human monoclonal antibody targeting the pan-B-cell antigenic marker CD20, was the first monoclonal antibody licensed for use in the treatment of cancer. Objective: This review focuses on the impact of rituximab in the treatment of patients with B-cell non-Hodgkin lymphoma (NHL). Methods: Three key areas related to the use of rituximab in B-cell NHL are discussed: mechanism of action, clinical efficacy in both indolent and aggressive disease, and safety of its use as both monotherapy and in combination with chemotherapy. Results/conclusions: Rituximab has demonstrated significant clinical efficacy in the treatment of NHL, particularly in combination with chemotherapy, and its use has revolutionized the treatment of both indolent and aggressive B-cell NHL over the past decade. Furthermore, consistent toxicity data have been obtained with a safe and tolerable profile in most patients.     

利妥昔单抗治疗类风湿关节炎的临床研究进展

利妥昔单抗是一种特异性针对CD20分子的基因工程抗体,能与B淋巴细胞表面的CD20结合,并通过补体介导的细胞毒作用等机制对B淋巴细胞进行特异性清除,从而达到治疗作用.利妥昔单抗最初作为抗淋巴瘤药物首先获得美国FDA认证,近年来被应用于类风湿关节炎等自身免疫病的治疗,取得了较好的疗效.现对其治疗类风湿关节炎的作用机制、临床应用和研究进展做一综述.     

利妥昔单抗治疗恶性淋巴瘤的进展

利妥昔单抗（人源化CD20单克隆抗体，商品名美罗华）是首个批准用于治疗表达CD20恶性淋巴省的单克隆抗体，广泛应用于低度恶性非雷奇金琳巴瘤（NHL）、侵袭性NHL，亦试用于霍奇金淋巴瘤（HL）及其他B细胞性恶性肿瘤。刊蚤昔单抗联合细胞毒性药物的疗效已在B细胞NHL的有关临床试验中得到证实。目前该药已被批准用于侵袭性淋巴瘤和惰性淋巴瘤的一线治疗，其维持治疗滤泡性淋巴瘤亦得出鼓舞人心的结果．利妥昔单抗已成为治疗B细胞性恶性淋巴瘤的重要手段之一。     

Rituximab: an innovative therapy for non-Hodgkin's lymphoma.

The epidemiology, etiology, classification, and treatment of non-Hodgkin's lymphoma (NHL) are reviewed, and rituximab, a newly available therapy, is discussed. NHL comprises a group of lymphoproliferative disorders the frequency of which continues to rise. Although many classification systems exist for identifying specific histological subtypes, NHL is generally divided into indolent (low-grade) and aggressive (intermediate- and high-grade) forms. Low-grade NHL is characterized by a slowly progressive, continually relapsing course, with eventual transformation to a more rapidly progressive form that is usually fatal. Several options are available for the management of indolent NHL; none is curative. Rituximab, a human-mouse monoclonal antibody that targets the CD20 antigen expressed in over 90% of B-cell NHLs, provides an alternative to conventional chemotherapy that is relatively safe and effective. In a Phase III trial involving 166 patients with relapsed or refractory low-grade B-cell NHL, rituximab produced an overall response of 48%, with 20 of 80 responders still in remission more than 36 months after treatment. Study results in patients with bulky disease and those requiring retreatment have also been encouraging. Most adverse effects associated with rituximab are mild to moderate. Infusion-related reactions occur more commonly during initial infusions and in patients with evidence of increased tumor burden but can be effectively managed with premedication, supportive care, and adjusted infusion rates. Hematologic effects are generally mild and transient, and adverse immune responses are rare. Rituximab is an alternative to conventional chemotherapy for the treatment of relapsed or refractory low-grade or follicular CD20-positive B-cell NHL.