Rituximab-associated neutropenia

Immune effector cell-associated haematotoxicity after CAR T-cell therapy: from mechanism to management

Genetically engineered chimeric antigen receptor (CAR) T cells have become an effective treatment option for several advanced B-cell malignancies. Haematological side-effects, classified in 2023 as immune effector cell-associated haematotoxicity (ICAHT), are very common and can predispose for clinically relevant infections. As haematopoietic reconstitution after CAR T-cell therapy differs from chemotherapy-associated myelosuppression, a novel classification system for early and late ICAHT has been introduced. Furthermore, a risk stratification score named CAR-HEMATOTOX has been developed to identify candidates at high risk of ICAHT, thereby enabling risk-based interventional strategies. Therapeutically, growth factor support with granulocyte colony-stimulating factor (G-CSF) is the mainstay of treatment, with haematopoietic stem cell (HSC) boosts available for patients who are refractory to G-CSF (if available). Although the underlying pathophysiology remains poorly understood, translational studies from the past 3 years suggest that CAR T-cell-induced inflammation and baseline haematopoietic function are key contributors to prolonged cytopenia. In this Review, we provide an overview of the spectrum of haematological toxicities after CAR T-cell therapy and offer perspectives on future translational and clinical developments.

Bispecific antibody therapies

Management of hematological malignancies is rapidly evolving from chemotherapy-based regimens toward targeted agents and immunotherapies, including bispecific antibodies (BsAbs). These novel and highly active treatments come with new side effect profiles. The hematological toxicities are common and potentially harmful, and the side effects have hitherto not been reviewed. With many BsAbs recently approved and entering routine clinical use, we have reviewed the rather limited published data and propose recommendations on the management of these toxicities. Our review of the available data confirms that hematological toxicities are among the most common toxicities, with potentially harmful consequences for the patients. Fortunately, hemophagocytic lymphohystiocytosis and disseminated intravascular coagulation are rare. Severe neutropenia and hypogammaglobulinemia are manageable, and their timely treatment and prevention may reduce morbidity and mortality.

Case report: Use of granulocyte-colony stimulating factor as an immunomodulatory therapy in a patient with neuromyelitis optica spectrum disorder and comorbid immunodeficiency

Background

Autoimmune diseases can coexist with immunodeficiency. We describe a treatment approach in which granulocyte-colony stimulating factor (G-CSF) is used to restore immune competence without worsening autoimmunity. G-CSF is a polyfunctional cytokine that influences survival, proliferation, and differentiation of hematopoietic stem cells, and has immunomodulatory effects on the innate and adaptive immune systems.

Objective

To report a case of neuromyelitis optica spectrum disorder (NMOSD) with comorbid immunodeficiency and frequent infections.

Methods

Case report and review of literature.

Results

A 23 years-old man presented with a focal onset seizure with impaired awareness at age 12. At age 18, he developed headaches, recurrent multifocal seizures, and non-convulsive status epilepticus. Brain magnetic resonance imaging (MRI) showed extensive T2 hyperintense and gadolinium-enhancing periventricular and corpus callosum lesions. Serum aquaporin 4 antibody was positive 1:10,000 (normal value <1.5 titer), hence he was diagnosed with NMOSD. As a complication, patient developed mucormycotic pneumonia with cavitation, requiring thoracotomy precluding use of immunosuppressants. Gene testing demonstrated a mutation in MT-ND4 gene encoding for NADH dehydrogenase 4 in mitochondrial complex 1. Eventually, he began a treatment with filgrastim, a G-CSF analog, in addition to intravenous immunoglobulins and prednisone. Patient's NMOSD has been in remission without relapses, or coexistent infections ever since.

Conclusion

G-CSF is a polyfunctional cytokine with important immunomodulatory effects, which makes it an interesting therapeutic option when autoimmunity coexists with immunodeficiency and was used successfully in this case.

A review of prophylactic regimens to prevent invasive fungal infections in hematology patients undergoing chemotherapy or stem cell transplantation

INTRODUCTION

The recent introduction of targeted therapies, including monoclonal antibodies, tyrosine-kinase inhibitors, and immunotherapies has improved the cure rate of hematologic patients. The implication of personalized treatment on primary antifungal prophylaxis will be discussed.

AREAS COVERED

We reviewed the literature for clinical trials reporting the rate of invasive fungal infections during targeted and cellular therapies and stem cell transplant, and the most recent international guidelines for primary antifungal prophylaxis.

EXPERT OPINION

As the use of personalized therapies is growing, the risk of invasive fungal infection has emerged in various clinical settings. Therefore, it is possible that the use of mold-active antifungal prophylaxis would spread in the next years and the risk of breakthrough infections would increase. The introduction of new antifungal agents in the clinical armamentarium is expected to reduce clinical unmet needs concerning the management of primary antifungal prophylaxis and improve outcome of patients.

Hypogammaglobulinemia, late-onset neutropenia, and infections following rituximab

Rituximab is a chimeric anti-CD20 monoclonal antibody that targets CD20-expressing B lymphocytes, has a well-defined efficacy and safety profile, and is broadly used to treat a wide array of diseases. In this review, we cover the mechanism of action of rituximab and focus on hypogammaglobulinemia and late-onset neutropenia-2 immune effects secondary to rituximab-and subsequent infection. We review risk factors and highlight key considerations for immunologic monitoring and clinical management of rituximab-induced secondary immune deficiencies. In patients treated with rituximab, monitoring for hypogammaglobulinemia and infections may help to identify the subset of patients at high risk for developing poor B cell reconstitution, subsequent infections, and adverse complications. These patients may benefit from early interventions such as vaccination, antibacterial prophylaxis, and immunoglobulin replacement therapy. Systematic evaluation of immunoglobulin levels and peripheral B cell counts by flow cytometry, both at baseline and periodically after therapy, is recommended for monitoring. In addition, in those patients with prolonged hypogammaglobulinemia and increased infections after rituximab use, immunologic evaluation for inborn errors of immunity may be warranted to further risk stratification, increase monitoring, and assist in therapeutic decision-making. As the immunologic effects of rituximab are further elucidated, personalized approaches to minimize the risk of adverse reactions while maximizing benefit will allow for improved care of patients with decreased morbidity and mortality.

Review of an Anti-CD20 Monoclonal Antibody for the Treatment of Autoimmune Diseases of the Skin

Biologic therapies targeting B-cells are emerging as an effective strategy to treat a variety of immune-mediated diseases. One of the most studied B-cell-targeted therapies is rituximab, an anti-CD20 monoclonal antibody that exemplifies B-cell depletion therapy and has served as the prototype for other anti-CD20 monoclonal antibodies and the development of biosimilars. While there are multiple studies on the use of rituximab in dermatology, a comprehensive review of rituximab therapy in autoimmune skin conditions is lacking. In this literature review, we summarize indications, treatment efficacy, and safety of rituximab among common autoimmune diseases of the skin: pemphigus vulgaris, cutaneous lupus erythematous, dermatomyositis, systemic sclerosis, thyroid dermopathy, autoimmune pemphigoid diseases, and cutaneous vasculitis diseases. Existing data on rituximab support the approach of rituximab, biosimilars, and newer B-cell-targeting therapies in immune-mediated cutaneous diseases. Overall, rituximab, which targets CD20, provides an effective alternative or concomitant option to traditional immunosuppressants in the management of various autoimmune diseases of the skin. Further studies are necessary to expand the understanding and possible utility of B-cell-targeted therapies among autoimmune skin diseases.

Late-onset toxicities of monoclonal antibodies in cancer patients

Cancer therapy duration is variable and may take years, adding a new challenge of maintaining the best life quality for cancer survivors. In cancer patients, late-onset toxicities have been reported with monoclonal antibodies and may involve several body organs or systems. They are defined as an autoimmune illnesses that can happen months to years after treatment discontinuation. Late-onset toxicities have become a focus of clinical care and related research. After cancer therapy is completed, the patient should receive longitudinal follow-up to detect these late effects as early as possible. The current review summarizes the recently reported late-onset toxicities of four classes of monoclonal antibodies (anti-CD52, anti-CTLA-4, anti-PD-1 and anti-CD20) with guidance for the diagnostic tools, appropriate management and treatment.

Practical guidance for the diagnosis and management of secondary hypogammaglobulinemia: A Work Group Report of the AAAAI Primary Immunodeficiency and Altered Immune Response Committees

Secondary hypogammaglobulinemia (SHG) is characterized by reduced immunoglobulin levels due to acquired causes of decreased antibody production or increased antibody loss. Clarification regarding whether the hypogammaglobulinemia is secondary or primary is important because this has implications for evaluation and management. Prior receipt of immunosuppressive medications and/or presence of conditions associated with SHG development, including protein loss syndromes, are histories that raise suspicion for SHG. In patients with these histories, a thorough investigation of potential etiologies of SHG reviewed in this report is needed to devise an effective treatment plan focused on removal of iatrogenic causes (eg, discontinuation of an offending drug) or treatment of the underlying condition (eg, management of nephrotic syndrome). When iatrogenic causes cannot be removed or underlying conditions cannot be reversed, therapeutic options are not clearly delineated but include heightened monitoring for clinical infections, supportive antimicrobials, and in some cases, immunoglobulin replacement therapy. This report serves to summarize the existing literature regarding immunosuppressive medications and populations (autoimmune, neurologic, hematologic/oncologic, pulmonary, posttransplant, protein-losing) associated with SHG and highlights key areas for future investigation.

Therapies for Membranous Nephropathy: A Tale From the Old and New Millennia

Primary Membranous Nephropathy (PMN) is the most frequent cause of nephrotic syndrome in adults. If untreated, PMN can lead to end-stage renal disease; moreover, affected patients are at increased risk of complications typical of nephrotic syndrome such as fluid overload, deep vein thrombosis and infection. The association of PMN with HLA-DQA1 and the identification in around 70% of cases of circulating autoantibodies, mainly directed towards the phospholipase A2 receptor, supports the autoimmune nature of the disease. In patients not achieving spontaneous remission or in the ones with deteriorating kidney function and severe nephrotic syndrome, immunosuppression is required to increase the chances of achieving remission. The aim of this review is to discuss the evidence base for the different immunosuppressive regimens used for PMN in studies published so far; the manuscript also includes a section where the authors propose, based upon current evidence, their recommendations regarding immunosuppression in the disease, while highlighting the still significant knowledge gaps and uncertainties.

Immune- and Non-Immune-Mediated Adverse Effects of Monoclonal Antibody Therapy: A Survey of 110 Approved Antibodies

Identification of new disease-associated biomarkers; specific targeting of such markers by monoclonal antibodies (mAbs); and application of advances in recombinant technology, including the production of humanized and fully human antibodies, has enabled many improved treatment outcomes and successful new biological treatments of some diseases previously neglected or with poor prognoses. Of the 110 mAbs preparations currently approved by the FDA and/or EMA, 46 (including 13 antibody–drug conjugates) recognizing 29 different targets are indicated for the treatment of cancers, and 66, recognizing 48 different targets, are indicated for non-cancer disorders. Despite their specific targeting with the expected accompanying reduced collateral damage for normal healthy non-involved cells, mAbs, may cause types I (anaphylaxis, urticaria), II (e.g., hemolytic anemia, possibly early-onset neutropenia), III (serum sickness, pneumonitis), and IV (Stevens–Johnson syndrome, toxic epidermal necrolysis) hypersensitivities as well as other cutaneous, pulmonary, cardiac, and liver adverse events. MAbs can provoke severe infusion reactions that resemble anaphylaxis and induce a number of systemic, potentially life-threatening syndromes with low frequency. A common feature of most of these syndromes is the release of a cascade of cytokines associated with inflammatory and immunological processes. Epidermal growth factor receptor-targeted antibodies may provoke papulopustular and mucocutaneous eruptions that are not immune-mediated.

Invasive Fungal Infections and Targeted Therapies in Hematological Malignancies

The use of targeted biologic therapies for hematological malignancies has greatly expanded in recent years. These agents act upon specific molecular pathways in order to target malignant cells but frequently have broader effects involving both innate and adaptive immunity. Patients with hematological malignancies have unique risk factors for infection, including immune dysregulation related to their underlying disease and sequelae of prior treatment regimens. Determining the individual risk of infection related to any novel agent is challenging in this setting. Invasive fungal infections (IFIs) represent one of the most morbid infectious complications observed in hematological malignancy. In recent years, growing evidence suggests that certain small molecule inhibitors, such as BTK inhibitors and PI3K inhibitors, may cause an increased risk of IFI in certain patients. It is imperative to better understand the impact that novel targeted therapies might have on the development of IFIs in this high-risk patient population.

Selective ABO immunoadsorption in hematopoietic stem cell transplantation with major ABO incompatibility

OBJECTIVE

ABO mismatch between donor and recipient occurs in 40% of allogeneic hematopoietic stem cell transplantations (HCT). Different strategies have been described to reduce isohemagglutinins (IHA) before HCT. We describe the effect of selective ABO immunoadsorption (ABO IA) on erythrocyte transfusion rate and the development of post-transplant pure red cell aplasia (ptPRCA).

METHODS

63 patients with major ABO incompatibility were retrospectively analyzed. Nine patients with major ABO incompatibility and high-IHA titer were treated by ABO IA before HCT. We analyzed the need for transfusion and the occurrence of ptPRCA. We compared the outcome with patients treated by other methods to reduce IHA.

RESULTS

In all nine patients treated by ABO IA, IHA decreased in a median four times. PtPRCA occurred in one patient. The median number of transfusions was 8 (range: 0-36) between d0 and d100. In 25 patients with high-IHA titer without treatment or treated by other methods to reduce IHA, the need for transfusions was comparable. No difference in the incidence of ptPRCA was observed.

CONCLUSIONS

Selective ABO IA is a feasible, safe, and effective method to reduce IHA before HCT in major ABO incompatibility. No effect on transfusion rate or ptPRCA compared to other strategies could be observed.

Risk of infection associated with targeted therapies for solid organ and hematological malignancies

Higher risks of infection are associated with some targeted drugs used to treat solid organ and hematological malignancies, and an individual patient’s risk of infection is strongly influenced by underlying diseases and concomitant or prior treatments. This review focuses on risk levels and specific suggestions for management, analyzing groups of agents associated with a significant effect on the risk of infection. Due to limited clinical experience and ongoing advances in these therapies, recommendations may be revised in the near future. Bruton tyrosine kinase (BTK) inhibitors are associated with a higher rate of infections, including invasive fungal infection, especially in the first months of treatment and in patients with advanced, pretreated disease. Phosphatidylinositol 3-kinase (PI3K) inhibitors are associated with an increased risk of Pneumocystis pneumonia and cytomegalovirus (CMV) reactivation. Venetoclax is associated with cytopenias, respiratory infections, and fever and neutropenia. Janus kinase (JAK) inhibitors may predispose patients to opportunistic and fungal infections; need for prophylaxis should be assessed on an individual basis. Mammalian target of rapamycin (mTOR) inhibitors have been linked to a higher risk of general and opportunistic infections. Breakpoint cluster region-Abelson (BCR-ABL) inhibitors are associated with neutropenia, especially over the first months of treatment. Anti-CD20 agents may cause defects in the adaptative immune response, hypogammaglobulinemia, neutropenia, and hepatitis B reactivation. Alemtuzumab is associated with profound and long-lasting immunosuppression; screening is recommended for latent infections and prevention strategies against CMV, herpesvirus, and Pneumocystis infections. Checkpoint inhibitors (CIs) may cause immune-related adverse events for which prolonged treatment with corticosteroids is needed: prophylaxis against Pneumocystis is recommended.

Management of immune thrombocytopenia in elderly patients

Despite the improvement in understanding its pathogenesis and the introduction of novel treatment options, the management of primary immune thrombocytopenia (ITP) still remains challenging. Considering its increased incidence with aging and prolonged life-expectancy, ITP is often diagnosed in elderly patients, a subset that deserves some special precautions. Ensure the diagnosis is a crucial step, and carefully attention must be given in excluding other causes of thrombocytopenia, especially among older people that frequently suffer from many comorbidities. When it comes to treatment decision, it is worth keeping into account that the elderly have an increased risk of bleeding, thrombosis and infections, that they often require many concomitant therapies, including antiplatelet or anticoagulant agents, and that treatment-related toxicities are often increased and sometimes more dangerous that the disease itself. There are not dedicated guidelines, and only few specific studies. Steroids with or without IVIG remain the first-line treatment. Splenectomy is less effective than in youngers and burdened by an increased thrombotic and infectious risk. Rituximab is a good option in non-immunocompromised patients, but long-term remissions are few. Eltrombopag and romiplostim have a good safety and efficacy profile, and have become a prominent drug in this subset, even if they are associated with a possible increased risk of thrombosis, and long-term toxicity is unknown. Other drugs, such as dapsone and danazol, have a well-known efficacy and safety profile, and still represent a valid option among elderly patients.

Incidence of neutropenia and use of granulocyte colony-stimulating factors in multiple myeloma: is current clinical practice adequate?

Although immunomodulatory drugs, alkylating agents, corticosteroids, protease inhibitors, and therapeutic monoclonal antibodies improve multiple myeloma outcomes, treatment burden is still an issue. Neutropenia is a known complication of cytotoxic cancer therapy and is often associated with infections; it is an important consideration in myeloma given the fact that patients often have a weakened immune system. The risk of febrile neutropenia increases with severe and persisting neutropenia. Recombinant granulocyte colony-stimulating factors (G-CSFs) are commonly used to reduce the incidence, duration, and severity of febrile neutropenia. Here, we review the risk and management of neutropenia associated with new and commonly used anti-myeloma agents. Few papers report the use of G-CSF in patients with multiple myeloma receiving anti-cancer treatments, and fewer describe whether G-CSF was beneficial. None of the identified studies reported G-CSF primary prophylaxis. Further studies are warranted to evaluate the need for G-CSF prophylaxis in multiple myeloma. Prophylaxis may be particularly useful in patients at high risk of prolonged severe neutropenia.

ESCMID Study Group for Infections in Compromised Hosts (ESGICH) Consensus Document on the safety of targeted and biological therapies: an infectious diseases perspective (Agents targeting lymphoid cells surface antigens [I]: CD19, CD20 and CD52)

BACKGROUND

The present review is part of the ESCMID Study Group for Infections in Compromised Hosts (ESGICH) Consensus Document on the safety of targeted and biological therapies.

AIMS

To review, from an Infectious Diseases perspective, the safety profile of agents targeting CD19, CD20 and CD52 and to suggest preventive recommendations.

SOURCES

Computer-based MEDLINE searches with MeSH terms pertaining to each agent or therapeutic family.

CONTENT

Although CD19-targeted agents (blinatumomab or inebilizumab) are not associated with an increased risk of infection, they may cause IgG hypogammaglobulinaemia and neutropenia. The requirement for prolonged intravenous infusion of blinatumomab may increase the risk of catheter-associated bloodstream infections. Infection remains the most common non-haematological adverse effect of anti-CD20 monoclonal antibodies, including severe respiratory tract infection, hepatitis B virus (HBV) reactivation and varicella-zoster virus infection. Screening for chronic or resolved HBV infection is recommended for patients receiving anti-CD20 monoclonal antibodies. Antiviral prophylaxis should be offered for 12-18 months to hepatitis B surface antigen (HBsAg)-positive and HBsAg-negative/anti-hepatitis B core antibody (HBc)-positive patients. Anti-Pneumocystis prophylaxis should be considered in patients receiving concomitant chemotherapy, particularly steroids. Alemtuzumab (anti-CD52) increases the risk of infections, in particular among leukaemia and solid organ transplant patients. These populations benefit from anti-Pneumocystis prophylaxis, prevention strategies for cytomegalovirus infection, and screening for HBV, hepatitis C virus and tuberculosis. Antiviral prophylaxis for at least 6-12 months should be provided for HBsAg-positive patients.

IMPLICATIONS

As there are limited clinical data for many of the reviewed agents, special attention must be given to promptly detect and report emerging infectious complications.

Impact of obinutuzumab alone and in combination for follicular lymphoma

Although rituximab-based chemoimmunotherapy prolongs the survival of patients with follicular lymphoma (FL), this disease is considered incurable in most patients. Thus, new therapies are needed not only for those in the relapsed/refractory setting, but also for initial treatment. Obinutuzumab (G, GA101) is a third-generation, fully humanized type II glycoengineered, anti-CD20 monoclonal antibody that results in increased direct cell death and antibody-dependent, cell-mediated cytotoxicity/phagocytosis compared to rituximab. Obinutuzumab has significant antitumor activity when used alone or in combinations in untreated or relapsed refractory FL patients. Studies have demonstrated its ability to prolong progression-free survival and, in some cases, overall survival, and to eliminate minimal residual disease. Several ongoing trials are investigating combinations with chemotherapy, immunomodulators, targeted drugs, and immunotherapy agents. G is generally well tolerated, with associated adverse effects including infusion-related reactions, neutropenia, thrombocytopenia, and reactivation of hepatitis B virus. Future studies with this antibody should focus on identifying predictive markers and developing chemotherapy-free combinations that will improve the outcome of patients with FL.

Description of late onset neutropenia in indolent lymphoma patients treated with bendamustine plus rituximab

Bendamustine (B) associated with rituximab (R) is widely described in literature for the management of patients with chronic lymphoid leukaemia (CLL) and indolent non-Hodgkin lymphoma. Safety data regarding late hematotoxicity such as late onset neutropenia (LON) are scarce. The aim of our study was to assess the incidence and to identify risk factors for LON in patients with indolent non-Hodgkin lymphoma and CLL treated with B and R (B-R). One hundred forty five patients were treated with B-R as first or second line. Patients with neutropenia prior induction treatment, treated beyond second line and relapsing within 3 months after the end of induction treatment, were excluded. Patients receiving at least 1 cycle of B-R and having LON during follow-up period were included and considered as eligible for toxicity assessment. A complete blood count was performed 4 weeks after the last cycle of induction treatment and thereafter every 3 months for 1 year. Thirty six patients were identified in our cohort (incidence of 25%), mostly affected by CLL (n = 11) and follicular lymphoma (FL) (n = 15). During follow-up, 84 events of LON were recorded, 61% and 39% were of grades 1/2 and 3/4, respectively. No episode of febrile neutropenia was documented. Amongst 13 of the 15 patients with FL undergoing R maintenance, 8 had treatment discontinuation because of LON. Median time for LON (grade > 2) and time to recovery (grade < 3) were of 11.2 and 17.3 weeks, respectively. One year after B-R induction, LON persisted in 4 patients. The risk of LON was increased both in patients with FL or CLL and performance status >1. The LON in B-R treated patients is clinically relevant. Close clinical and biological follow-up and treatment prophylaxis (eg, valaciclovir and cotrimoxazole) especially for FL patients undergoing maintenance with R monotherapy seems relevant.

Rituximab for immunologic renal disease: What the nephrologist needs to know

Rituximab (RTX), a chimeric, monoclonal anti-CD20 antibody, is increasingly used in immune-mediated renal diseases. While licensed in the induction treatment of ANCA-associated vasculitis, it represents one of the most commonly prescribed off-label drugs. Much of the information regarding its safety has been drawn from experience in hematology and rheumatology. Ample evidence illustrates the safety of RTX, however, rare but serious adverse events have emerged that include progressive multifocal leucoencephalopathy and hepatitis B reactivation. Moderate to severe hypogammaglobulinemia and late-onset neutropenia following RTX therapy confer an increased infectious risk and factors predicting these side effects (i.e. a genetic basis) need to be identified. Nephrologists initiating RTX need to bear in mind that long-term risks and optimal dosing for many renal indications remain unclear. Special considerations must be given when RTX is used in women of childbearing age. We summarize practical aspects concerning the use of RTX. This review will provide nephrologists with information to guide their use of RTX alerting them to safety risks and the need for patient counselling.

The clinical development of obinutuzumab for the treatment of follicular lymphoma

Impressive progress has been made in recent decades for advanced-stage follicular lymphoma with the availability of anti-CD20 monoclonal antibodies, initially rituximab and more recently obinutuzumab. Obinutuzumab is a unique, third-generation, fully humanized glycoengineered IgG1 type II anti-CD20 monoclonal antibody. It has been shown to have increased antitumor activity compared to rituximab in preclinical studies, including whole-blood B-cell depletion assays, xenograft models, and primate models. This has spurred on the development of obinutuzumab through Phase I/II trials as monotherapy and in combination with chemotherapeutic agents and other targeted therapies. Its efficacy compared to rituximab and in rituximab-refractory disease has led to its continued development and eventual approval for the treatment of follicular lymphoma. Here in this review, we highlight the design and development of obinutuzumab in the treatment of advanced stage grade 1-3A follicular lymphoma and its future directions.

Incidence of late onset neutropenia associated with rituximab use in B cell lymphoma patients undergoing autologous stem cell transplantation

Reversible late onset neutropenia associated with rituximab has been reported with incidence rates varying from 15 to 70% in B cell lymphoma patients receiving autologous stem cell transplantation. We conducted a retrospective descriptive study at one tertiary care center in adult B cell lymphoma patients treated with rituximab and autologous stem cell transplantation between 1 January 2004 and 30 June 2014. Late onset neutropenia was defined as an absolute neutrophil count <1.0 × 109 cells/L after neutrophil engraftment and less than six months post autologous stem cell transplantation. The primary objective was to determine the incidence of late onset neutropenia. The secondary objectives were to examine whether the use of rituximab with re-induction therapy, mobilization or high dose chemotherapy regimens increased the risk for late onset neutropenia, and to evaluate infectious complications. Of 315 subjects, 92 (29.2%) developed late onset neutropenia. Mobilization regimens containing rituximab (OR 2.90 95% CI: 1.31–6.40), high dose chemotherapy containing rituximab (OR 1.87 95% CI: 1.14–3.05), and exposure to rituximab in either or both regimens (OR 3.05 95% CI: 1.36–6.88) significantly increased the risk of late onset neutropenia. While neutropenic, 17.4% experienced an infection, 7.6% experienced febrile neutropenia, and 5.4% were hospitalized. In conclusion, rituximab with mobilization or high dose chemotherapy may increase the risk of late onset neutropenia post autologous stem cell transplantation.

Drug-Induced Neutropenia: A Focus on Rituximab-Induced Late-Onset Neutropenia

Rituximab can cause late-onset neutropenia that may result in serious life-threatening complications. The author describes the pathophysiology, incidence, and management of this adverse reaction and presents two case histories.

Treatment Emergent Agranulocytosis with Skin and Gingival Lesions in a Chronic Lymphocytic Leukemia Patient: A Case Report

Chronic Lymphocytic Leukaemia (CLL) is a monoclonal lymphoid malignancy characterized by progressive accumulation of small, mature but functionally incompetent neoplastic lymphocytes in the peripheral blood, bone marrow and lymphoid organs. Patients present a variable course and may not require early intervention unlike other malignancies. Patients with rapidly deteriorating blood counts, and organomegaly need treatment. Alkylating agent live Bendamustine combined with Rituximab, anti-CD 20 monoclonal antibody have shown promising results in such patients. Anaemia, neutropenia and thrombocytopenia have been reported as treatment emergent events with this combination therapy. Neutrophils are the major innate defense and their depletion can result in a wide range of opportunistic infections. This case report discusess the oral and dermal lesions which emerged with the Rituximab and Bendamustine combination therapy in a patient with CLL and their management.

Safety and tolerability of an anti-CD19 monoclonal antibody, MEDI-551, in subjects with systemic sclerosis: a phase I, randomized, placebo-controlled, escalating single-dose study

Background

Systemic sclerosis (SSc) is a clinically heterogeneous, life-threatening disease characterized by fibrosis, microvasculopathy, and autoimmunity. Extensive nonclinical and clinical data implicate B cells in the pathogenesis of SSc. MEDI-551 is an investigational humanized monoclonal antibody that targets the B cell surface antigen CD19 and mediates antibody-dependent, cell-mediated cytotoxicity of B cells. This clinical study evaluated the safety and tolerability, pharmacokinetics, and pharmacodynamics of MEDI-551 in subjects with SSc.

Methods

This phase I multicenter, randomized, double-blind, placebo-controlled, single escalating dose study enrolled adult subjects with either limited or diffuse cutaneous SSc. A single intravenous dose of MEDI-551 was administered, and safety and tolerability were evaluated. MEDI-551 pharmacokinetics (PK), pharmacodynamics, and immunogenicity were also assessed. Safety assessments included the incidence of adverse events and changes in clinical and laboratory results. MEDI-551 serum concentrations, effects on circulating and tissue B cells and plasma cells (PCs), and antidrug antibodies were analyzed. Modified Rodnan skin score (MRSS) and pulmonary function tests were used to explore the clinical effect of MEDI-551.

Results

The study enrolled 28 subjects with SSc (mean age, 47.3 years; 67.9 % female). Twenty-four received a single dose of MEDI-551 (0.1–10.0 mg/kg) and four received placebo. Treatment-emergent adverse events (TEAEs) occurred in 95.8 % of subjects in the MEDI-551 group and in 75.0 % of subjects in the placebo group; the majority of TEAEs were mild or moderate in severity. Two serious adverse events were considered possibly related to the study drug. One death, deemed not related to the study drug, occurred in a MEDI-551-treated subject. MEDI-551 exhibited linear PK in the dose range of 1.0 to 10.0 mg/kg, and more rapid clearance at lower doses. Dose-dependent depletion of circulating B cells and plasma cells was observed. MRSS assessments suggest a possible clinical effect of MEDI-551 on affected skin.

Conclusions

A single escalating dose of MEDI-551 was tolerable and safe in this subject population. B cell depletion was achieved and was dose dependent. A signal of clinical effect was observed. Based on these results, further investigation of MEDI-551 as a disease-modifying treatment for SSc is warranted.

Trial registration

www.clinicaltrials.gov identifier, NCT00946699; registered 23 July 2009.

Late-onset neutropenia after rituximab in ANCA-associated vasculitis

BACKGROUND

Rituximab (RTX) is being used increasingly in anti-neutrophil cytoplasmatic antibody (ANCA)-associated vasculitis (AAV). Late-onset neutropenia (LON) and risks of infections have been observed following RTX therapy in rheumatological diseases including granulomatosis with polyangiitis (GPA) but data on microscopic polyangiitis (MPA) are lacking.

METHOD

We studied the occurrence of LON in 59 AAV (47 GPA/12 MPA) patients treated with RTX. Patient charts were retrospectively reviewed for the occurrence of LON and clinical data were extracted and included in the analysis.

RESULTS

Seven of the total 59 patients (11.9%) developed LON after a median time of 86 days (range 56-168 days) since their latest RTX treatment. Of these seven LON patients, 5/47 (10.6%) had a diagnosis of GPA and 2/12 (16.7%) of MPA. Three of the patients developed LON after the first RTX treatment and four had received repeated courses. Five LON patients developed infectious symptoms. Six of the patients were hospitalized. Retreatment with RTX was given in three cases without further LON episodes.

CONCLUSIONS

LON is a potentially severe side-effect of RTX occurring in both GPA and MPA and may develop after both single and repeated treatment courses. As infections are commonly seen, the condition requires an increased awareness. No predisposing factors for LON were identified.

A phase II randomized trial comparing standard and low dose rituximab combined with alemtuzumab as initial treatment of progressive chronic lymphocytic leukemia in older patients: a trial of the ECOG-ACRIN cancer research group (E1908)

Chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL) patients requiring initial therapy are often older and frailer and unsuitable candidates for standard chemoimmunotherapy regimens. Shorter duration combination monoclonal antibody (mAb) therapy using alemtuzumab and rituximab has been shown to be effective and tolerable treatment for CLL. Standard dose anti-CD20 mAb therapy causes loss of CD20 expression by surviving CLL cells, which can be minimized by decreasing the mAb dose. We report a randomized phase II clinical trial enrolling older (≥ 65 years) patients (median age 76 years, n = 31) with treatment naïve progressive CLL. Patients received 8-12 weeks of standard subcutaneous alemtuzumab with either intravenous standard (375 mg/m(2) weekly)(n = 16) or low dose (20 mg/m(2) 3x week)(n = 15) rituximab. This study was closed before full accrual because the manufacturer withdrew alemtuzumab for treatment of CLL. The overall response rate was 90% with an 45% complete response rate, median progression-free survival of 17.9 months and no significant differences in outcome between the low and standard dose rituximab arms. The major toxicities were cytopenia and infection with one treatment fatality caused by progressive multifocal leukoencephalopathy but no other opportunistic infections. Combination mAb therapy was effective and tolerable treatment for older and frailer patients with progressive CLL, achieving a high rate of complete remissions. These data support the role of mAb in therapy for less fit CLL patients and the further study of low dose higher frequency anti-CD20 mAb therapy as a potentially more effective use of anti-CD20 mAb in the treatment of CLL.

Secondary autoimmune cytopenias in chronic lymphocytic leukemia

Secondary autoimmune cytopenias in chronic lymphocytic leukemia are distinct clinical entities that require specific management. These autoimmune disorders have a complex pathogenesis that involves both the leukemic cells and the immune environment in which they exist. The mechanism is not the same in all cases, and to varying degrees involves the chronic lymphocytic leukemia (CLL) cells in antibody production, antigen presentation, and stimulation of T cells and bystander polyclonal B cells. Diagnosis of autoimmune cytopenias can be challenging as it is difficult to differentiate between autoimmunity and bone marrow failure due to disease progression. There is a need to distinguish these causes, as prognosis and treatment are not the same. Evidence regarding treatment of secondary autoimmune cytopenias is limited, but many effective options exist and treatment can be selected with severity of disease and patient factors in mind. With new agents to treat CLL coming into widespread clinical use, it will be important to understand how these will change the natural history and treatment of autoimmune cytopenias.

Incidence and description of autoimmune cytopenias during treatment with ibrutinib for chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is frequently complicated by secondary autoimmune cytopenias (AICs). Ibrutinib is an irreversible inhibitor of Bruton's tyrosine kinase approved for the treatment of relapsed CLL and CLL with del(17p). The effect of ibrutinib treatment on the incidence of AIC is currently unknown. We reviewed medical records of 301 patients treated with ibrutinib, as participants in therapeutic clinical trials at The Ohio State University Comprehensive Cancer Center between July 2010 and July 2014. Subjects were reviewed with respect to past history of AIC, and treatment-emergent AIC cases were identified. Before starting ibrutinib treatment, 26% of patients had experienced AIC. Information was available for a total of 468 patient-years of ibrutinib exposure, during which there were six cases of treatment-emergent AIC. This corresponds to an estimated incidence rate of 13 episodes for every 1000 patient-years of ibrutinib treatment. We further identified 22 patients receiving therapy for AIC at the time ibrutinib was started. Of these 22 patients, 19 were able to discontinue AIC therapy. We found that ibrutinib treatment is associated with a low rate of treatment-emergent AIC. Patients with an existing AIC have been successfully treated with ibrutinib and subsequently discontinued AIC therapy.

Treatment Options for Primary Autoimmune Hemolytic Anemia: A Short Comprehensive Review

Until now, treatment of primary autoimmune hemolytic anemia of the warm type (wAIHA) is primarily based on immunosuppression. However, many patients do not respond adequately to treatment, and treated patients may develop severe side effects due to uncontrolled, mixed and/or long-lasting immunosuppression. Unfortunately, the newly used therapeutic monoclonal antibodies are unspecific and remain frequently ineffective. Thus, development of a specific therapy for AIHA is necessary. The ideal therapy would be the identification and elimination of the causative origin of autoimmunization and/or the correction or reprogramming of the dysregulated immune components. Blood transfusion is the most rapidly effective measure for patients who develop or may develop hypoxic anemia. Although some effort has been made to guide physicians on how to adequately treat patients with AIHA, a number of individual aspects should be considered prior to treatment. Based on my serological and clinical experience and the analysis of evidence-based studies, we remain far from any optimized therapeutic measures for all AIHA patients. Today, the old standard therapy using controlled steroid administration, with or without azathioprine or cyclophosphamide, is, when complemented with erythropoiesis-stimulating agents, still the most effective therapy in wAIHA. Rituximab or other monoclonal antibodies may be used instead of splenectomy in therapy-refractory patients.

Late-onset neutropenia after treatment with rituximab for rheumatoid arthritis and other autoimmune diseases: data from the AutoImmunity and Rituximab registry

Objectives

To evaluate the prevalence of late-onset neutropenia and its complications in patients treated with rituximab (RTX) for rheumatoid arthritis (RA) and other autoimmune diseases (AIDs) in a prospective registry.

Methods

The AutoImmunity and Rituximab registry is an independent 7-year prospective registry promoted by the French Society of Rheumatology. For each episode of neutropenia, data were validated by the clinician in charge of the patient.

Results

Among 2624 patients treated with RTX for refractory AIDs, and at least 1 follow-up visit (a total follow-up of 4179 patient-years in RA and 987 patient-years in AIDs), late-onset neutropenia was observed in 40 patients (25 RA (1.3% of patients with RA, 0.6/100 patient-years), and AIDs in 15 (2.3% of patients with AIDs, 1.5/100 patient-years)). 6 patients (15%) had neutrophils <500/mm³, 8 (20%) had neutrophils between 500 and 1000/mm³, and 26 (65%) had neutrophils between 1000 and 1500/mm³. Neutropenia occurred after a median period of 4.5 (3–6.5) months after the last RTX infusion in patients with RA, and 5 (3–6.5) months in patients with AIDs. 5 patients (12.5%), 4 of them with neutrophils lower than 500/mm³, developed a non-opportunistic serious infection and required antibiotics and granulocyte colony-stimulating factor injections, with a favourable outcome. After resolution of their RTX-related neutropenia, 19 patients (47.5%) were re-treated, and neutropenia reoccurred in 3 of them.

Conclusions

Late-onset neutropenia might occur after RTX and may result in serious infections. Thus, monitoring of white cell count should be performed after RTX. However, in this large registry of patients with AIDs, the frequency of RTX-induced neutropenia was much lower than that previously reported in patients treated for blood malignancies or AIDs.

Rituximab-related late-onset neutropenia in patients with rheumatic diseases: successful re-challenge of the treatment

BACKGROUND

We describe here 2 patients who developed late-onset neutropenia after Rituximab treatment. While this phenomenon is well described among patients suffering from hematological malignancies, such adverse effects are rare among patients with rheumatic diseases.

CASE REPORT

Two patients, the first with rheumatoid arthritis and the second with granulomatosis with polyangiitis, were treated by Rituximab after all previous treatments failed. The patients developed late-onset neutropenia after several courses of treatment. The first patient, with symptomatic neutropenia, recovered after a single dose of granulocyte macrophage stimulating factor, and the second patient's neutrophils increased spontaneously. Both patients were retreated by rituximab in their scheduled time without further complications.

CONCLUSIONS

Our case series is unique because the same phenomenon appeared in patients with different rheumatic diseases. This case series confirms the possibility of continuing the treatment without further adverse effects.

Anemia as a useful biomarker in patients with diffuse large B-cell lymphoma treated with R-CHOP immunochemotherapy

The aim of the current study is to evaluate the prognostic value of anemia, an easily estimable parameter in patients with diffuse large B-cell lymphoma treated with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP) immunochemotherapy. A total of 157 patients with newly diagnosed diffuse large B-cell lymphoma treated with ≥1 cycle of R-CHOP were included. Hemoglobin level without red cell transfusion within 7 days of initiation of treatment was chosen as a parameter of baseline cancer-induced anemia. To investigate the clinical significance of chemotherapy-induced anemia and its recovery after completion of treatment, 87 patients in complete remission for ≥6 months from the time of the last cycle of R-CHOP were grouped and analyzed separately. Patients with a cancer-induced anemia of hemoglobin <10 g/dL showed inferior event-free and disease-free survival compared to those with hemoglobin ≥10 g/dL. This finding was observed irrespective of the status of pre-treatment bone marrow involvement. In multivariate analysis, hemoglobin <10 g/dL was found to be an international prognostic index-independent prognostic factor. Risk of relapse was significantly higher for patients who were still anemic at 6 months after R-CHOP, compared to those who achieved complete recovery from chemotherapy-induced anemia within 6 months.

Autoimmune cytopenias in chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is frequently complicated by secondary autoimmune cytopenias (AIC) represented by autoimmune hemolytic anemia (AIHA), immune thrombocytopenia (ITP), pure red cell aplasia, and autoimmune granulocytopenia. The distinction of immune cytopenias from cytopenias due to bone marrow infiltration, usually associated with a worse outcome and often requiring a different treatment, is mandatory. AIHA and ITP are more frequently found in patients with unfavorable biological risk factors for CLL. AIC secondary to CLL respond less favorably to standard treatments than their primary forms, and treating the underlying CLL with chemotherapy or monoclonal antibodies may ultimately be necessary.

Safety and efficacy of rituximab in adult immune thrombocytopenia: results from a prospective registry including 248 patients

We conducted a prospective multicenter registry of 248 adult patients with immune thrombocytopenia (ITP) treated with rituximab to assess safety. We also assessed response and predictive factors of sustained response. In total, 173 patients received 4 infusions of 375 mg/m(2) and 72 received 2 fixed 1-g infusions 2 weeks apart. The choice of the rituximab regimen was based on the physician's preference and not patient characteristics. Overall, 38 patients showed minor intolerance to rituximab infusions; infusions had to be stopped for only 3 patients. Seven showed infection (n = 11 cases), with an incidence of 2.3 infections/100 patient-years. Three patients died of infection 12 to 14 months after rituximab infusions, but the role of rituximab was questionable. In total, 152 patients (61%) showed an overall initial response (platelet count ≥30 × 10(9)/L and ≥2 baseline value). At a median follow-up of 24 months, 96 patients (39%) showed a lasting response. On multivariate analysis, the probability of sustained response at 1 year was significantly associated with ITP duration <1 year (P = .02) and previous transient complete response to corticosteroids (P = .05). The pattern of response was similar with the 2 rituximab regimens. With its benefit/risk ratio, rituximab used off-label may remain a valid option for treating persistent or chronic ITP in adults. This trial was registered at www.clinicaltrials.gov as #NC1101295.

Obinutuzumab (GA101) in relapsed/refractory chronic lymphocytic leukemia: final data from the phase 1/2 GAUGUIN study

GAUGUIN evaluated the safety and efficacy of obinutuzumab (GA101) monotherapy in patients with relapsed/refractory chronic lymphocytic leukemia (CLL). In phase 1 (dose escalation), 13 patients received obinutuzumab 400 to 1200 mg (days 1 and 8 of cycle 1; day 1 of cycles 2-8). In phase 2, 20 patients received a fixed dose of 1000 mg (days 1, 8, and 15 of cycle 1; day 1 of cycles 2-8). Infusion-related reactions occurred in nearly all patients, but few were grade 3/4. Grade 3/4 neutropenia occurred in 7 patients in phase 1 (but was not dose-related) and in 4 patients in phase 2. Overall end-of-treatment response (all partial responses) was 62% (phase 1) and 15% (phase 2); best overall response was 62% and 30%, respectively. Phase 2 median progression-free survival was 10.7 months and median duration of response was 8.9 months. In summary, obinutuzumab monotherapy is active in patients with heavily pretreated relapsed/refractory CLL.

Rituximab use in pediatric central demyelinating disease

BACKGROUND

Rituximab is a B-cell therapy used off-label to reduce relapses in adult demyelinating diseases. There is limited knowledge of its clinical use in pediatric neuromyelitis optica and multiple sclerosis. Demyelinating diseases in children can have high morbidity, and B-cell therapies hold promise for those with a severe course. Our study investigates the clinical experience of safety and efficacy with rituximab in children with demyelinating diseases of the central nervous system.

METHODS

This is a retrospective case series of 11 patients with pediatric neuromyelitis optica and multiple sclerosis who received at least one rituximab infusion at the Pediatric Multiple Sclerosis Clinic, University of California, San Francisco. Each patient was infused up to 1000 mg twice 2 weeks apart. Patients were monitored prospectively, and relapse events, laboratories, and adverse reactions were recorded.

RESULTS

Eight children with neuromyelitis optica, two with relapsing-remitting multiple sclerosis and one with secondary-progressive multiple sclerosis received rituximab treatment. The median number of cycles was 3. Most patients (82%, n = 9) experienced reduction of relapses after initiating rituximab. There were no serious infections. Infusion reactions were reported in three patients and managed successfully in subsequent infusions with increased pretreatment (dexamethasone and diphenhydramine) and use of slower infusion rates. Rituximab was not discontinued in any child because of side effects; two switched treatment therapy after 4.5 and 11 months because of relapses.

CONCLUSIONS

The use of rituximab in our pediatric neuromyelitis optica and multiple sclerosis cohort was overall safe and effective. Larger studies should confirm our observations.

B-cell depletion in immune thrombocytopenia

B cells play an important role in the immune response and can lead to the development of autoimmune diseases and particularly immune thrombocytopenia (ITP). A rational approach to ITP treatment could involve B-cell depletion such as with rituximab. Rituximab is a chimeric monoclonal antibody directed against CD20 molecule. It has direct effects on antibody production and indirect effects on cellular immunity. Rituximab demonstrated an overall response rate of 62.5% that lasted from 2-48 months. The ability of rituximab as an effective splenectomy-avoiding option was recently confirmed in a meta-analysis of randomized clinical trials and observational studies including 368 patients with an overall response rate of 57%. However, the estimated 5- year response is only 21% in adults. Rituximab appears to be well tolerated, but we lack studies of long-term tolerance. The optimal time to administer rituximab for ITP remains unclear. There is consensus to administer corticosteroids or intravenous immunoglobulin (IVIg) as first-line therapy in ITP. A panel of experts was unable to formulate a clear strategy for the respective place of splenectomy, thrombopoietin-receptor agonists, and rituximab as second-line treatment. Among new-generation CD20-targeted therapy, only veltuzumab has been tested for ITP. Preliminary study suggests that it could have similar efficacy to rituximab. Options other than anti-CD20 treatment may modulate and/or inhibit the B-cell compartment. Several monoclonal antibodies (MoAbs) directed against different B-lymphocyte receptors or structures implicated in the cooperation between B and T lymphocytes have been successfully tested in various autoimmune diseases. Testing these options in ITP will be an exciting challenge.

Adverse events to monoclonal antibodies used for cancer therapy: Focus on hypersensitivity responses

Fifteen monoclonal antibodies (mAbs) are currently registered and approved for the treatment of a range of different cancers. These mAbs are specific for a limited number of targets (9 in all). Four of these molecules are indeed directed against the B-lymphocyte antigen CD20; 3 against human epidermal growth factor receptor 2 (HER2 or ErbB2), 2 against the epidermal growth factor receptor (EGFR), and 1 each against epithelial cell adhesion molecule (EpCAM), CD30, CD52, vascular endothelial growth factor (VEGF), tumor necrosis factor (ligand) superfamily, member 11 (TNFSF11, best known as RANKL), and cytotoxic T lymphocyte-associated protein 4 (CTLA4). Collectively, the mAbs provoke a wide variety of systemic and cutaneous adverse events including the full range of true hypersensitivities: Type I immediate reactions (anaphylaxis, urticaria); Type II reactions (immune thrombocytopenia, neutopenia, hemolytic anemia); Type III responses (vasculitis, serum sickness; some pulmonary adverse events); and Type IV delayed mucocutaneous reactions as well as infusion reactions/cytokine release syndrome (IRs/CRS), tumor lysis syndrome (TLS), progressive multifocal leukoencephalopathy (PML) and cardiac events. Although the term "hypersensitivity" is widely used, no common definition has been adopted within and between disciplines and the requirement of an immunological basis for a true hypersensitivity reaction is sometimes overlooked. Consequently, some drug-induced adverse events are sometimes incorrectly described as "hypersensitivities" while others that should be described are not.

Rituximab biosimilars

INTRODUCTION

Rituximab is a monoclonal antibody targeting CD20, used to treat B cell malignancies and B cell-mediated autoimmune diseases. Rituximab has the largest market of any monoclonal antibody therapeutic. Its patent will expire within the next few years and several manufacturers have already produced or are developing rituximab biosimilars that aim to match the innovator rituximab as closely as possible.

AREAS COVERED

In this review, we discuss key factors that determine the efficacy of rituximab therapy, potential technical challenges in the manufacture and evaluation of biosimilars, regulatory considerations regarding the review and approval of biosimilars, and the current status of biosimilar rituximab development by various manufacturers. Due to the nature of the topic, literature searches included conference abstracts, regulatory and industry websites as well as peer reviewed literature.

EXPERT OPINION

Cost is a key limitation of current biologics usage and there is a political impetus to the licensing of biosimilars. Concerns regarding potential dissimilarities of biosimilars are legitimate, but surmountable with techniques for in vitro, in vivo and clinical testing and more clearly defined regulatory requirements. These should provide reassurance to prescribers. However, the cost of manufacturing and licensing a biosimilar remains high and the reduction in cost may be more limited than for a non-biologic small molecule drug and its generic version. This cost reduction will be critical to the impact and use of rituximab biosimilars.

Rituximab for remission induction and maintenance in refractory granulomatosis with polyangiitis (Wegener's): ten-year experience at a single center

OBJECTIVE

This study was conducted to evaluate the efficacy and safety of repeated and prolonged B cell depletion with rituximab (RTX) for the maintenance of long-term remission in patients with chronic relapsing granulomatosis with polyangiitis (Wegener's) (GPA).

METHODS

We conducted a single-center observational study of all patients with chronic relapsing GPA treated with at least 2 courses of RTX between January 1, 2000 and May 31, 2010. Participants in the Rituximab in ANCA-Associated Vasculitis (RAVE) trial were excluded from this analysis. Data were abstracted from electronic medical records.

RESULTS

Fifty-three patients with refractory GPA (median age 46 years [interquartile range (IQR) 30-61 years]; 53% women) received at least 2 courses of RTX to treat GPA relapses or to maintain remission. All but 1 patient had antineutrophil cytoplasmic antibodies (ANCA) against proteinase 3 (PR3). These patients received a median of 4 courses of RTX (IQR 3-5); all had depletion of B cells, and the median time to return of B cells was 8.5 months (IQR 6-11 months). All observed relapses occurred after reconstitution of B cells and were accompanied or preceded by an increase in ANCA levels, except for the 1 ANCA-negative patient. Infusion-related adverse events occurred in 16 patients. During the period of B cell depletion, 30 infections requiring antimicrobial therapy were recorded.

CONCLUSION

RTX appeared to be effective and safe for the induction and maintenance of remission in patients with chronic relapsing GPA. Repeated depletion of B lymphocytes seems to be associated with a low risk of infections. Preemptive re-treatment decisions can be individualized based on serial B lymphocyte and PR3 ANCA monitoring. The use of RTX for the maintenance of long-term remission merits further formal investigation.

Characteristics of late onset neutropenia in rheumatologic patients treated with rituximab: a case review analysis from a single center

BACKGROUND

Late onset neutropenia (LON) secondary to rituximab has been reported as an adverse event in the treatment of hematological malignancies but reports on autoimmune diseases are scarce.

AIM

To review the characteristics of LON in rheumatologic patients from a single center.

DESIGN

Retrospective case record study.

METHODS

Clinical and laboratory data since the introduction of rituximab in our clinic in 2006 were collected and analyzed retrospectively. LON was defined as an absolute neutrophil count <1.0 × 10(9)/l occurring 4 weeks after the last rituximab infusion.

RESULTS

LON was identified in eight patients (6% of all patients receiving rituximab). All patients had complicated and refractory disease and had been treated with a median of 4.5 different immunosuppressive drugs prior to rituximab. LON appeared after a median interval of 23 weeks with recovery of LON after a median of 6.5 days. Four patients had concomitant infection at the onset of neutropenia, when six patients had both low immunoglobulin M and immunoglobulin G. Six patients were rechallenged with rituximab without recurrence of LON.

CONCLUSION

The characteristics of LON after rituximab treatment in patients with autoimmune disease are comparable with experiences from hematological malignancies. LON seems to precede B-cell recovery implying a perturbation of the granulocyte homeostasis. LON with its rapid recovery does not seem to increase the risk for serious infection in contrast to the sustained hypogammaglobulinemia that may follow rituximab. The risk of LON recurrence after rechallenge is low.