Efficacy and Safety of Rituximab for Refractory and Relapsing Thrombotic Thrombocytopenic Purpura: A Cohort of 10 Cases

Severe primary refractory thrombotic thrombocytopenic purpura (TTP) in the post plasma exchange (PEX) and rituximab era

Acute acquired thrombotic thrombocytopenic purpura (TTP) requires prompt recognition and initiation of plasma exchange (PEX) therapy and immunosuppression. When PEX fails, mortality nears 100%, making finding an effective treatment crucial. Primary refractory TTP occurs when initial therapies fail or if exacerbations occur during PEX therapy, both signifying the need for treatment intensification to achieve clinical remission. Rituximab helps treat most of the refractory TTP cases, except those that are severely refractory. A paucity of studies guiding severely refractory TTP makes management arbitrary and individualised, highlighting the value of isolated reports. We present an extremely rare case of primary refractory TTP with an insufficient platelet response to numerous types of treatments, including emerging therapies such as caplacizumab, on the background of repeated PEX and immunosuppressive therapies.

Efficacy and safety of rituximab in autoimmune and microangiopathic hemolytic anemia: a systematic review and meta-analysis

Background

The efficacy and safety of rituximab (RTX) on hemolytic anemia (HA) is unknown. Therefore we retrospectively analyze the efficacy and safety of RTX in autoimmune hemolytic anemia (AIHA) and microangiopathic hemolytic anemia (MAHA) from the previous literature.

Methods

Data in clinical trials and observational studies were collected from PubMed, Cochrane, Embase, and Google Scholar until Oct 15, 2018. The efficacy and safety of RTX in patients with AIHA or MAHA were assessed and overall response rates (ORRs), complete response rates (CRRs), adverse events (AEs) and relapse rates (RRs) were extracted if available. A meta-analysis was performed with a random-effects model, estimating mean proportions in all studies, and relative rates in comparative studies.

Results

After quality assessment, a total of 37 investigations encompassing 1057 patients eligible for meta-analysis were included. Pooled mean proportion of ORR was 0.84 (95% confidence interval [CI] 0.80–0.88), and that of CRR was 0.61 (95% CI 0.49–0.73). Mean AE rate was 0.14 (95% CI 0.10–0.17), and mean RR was 0.21 (95% CI 0.15–0.26). Relative ORR was 1.18 (95% CI 1.02–1.36), and relative CRR was 1.17 (95% CI 0.98–1.39) fold more than the respective non-RTX counter parts. Relative AE rate was 0.77 (95% CI 0.36–1.63), and relative RR was 0.93 (95% CI 0.56–1.55) fold less than the respective non-RTX counter parts.

Conclusion

RTX is more effective than the treatments without RTX for AIHA and MAHA and is well-tolerated.

Rituximab Twice Weekly for Refractory Thrombotic Thrombocytopenic Purpura in a Critically Ill Patient with Acute Respiratory Distress Syndrome

Thrombotic thrombocytopenic purpura (TTP) is a rare, serious, life-threatening disease characterized by microangiopathic hemolytic anemia, thrombocytopenia, and hypercoagulability. The etiology is a deficiency of ADAMTS13 which is usually caused by acquired antibodies. Plasma exchange and steroids is the standard of care in the treatment of TTP. However, there are refractory cases of TTP which require further management. Rituximab appears to be a safe and effective therapy for refractory and relapsing TTP. Here we report a challenging case of TTP that responded to treatment with rituximab twice weekly. According to our knowledge, rituximab twice weekly has never been used for TTP before.

Phase II clinical trial testing the safety of a humanised monoclonal antibody anti-CD20 in patients with heart failure with reduced ejection fraction, ICFEr-RITU2: study protocol

INTRODUCTION

Chronic heart failure with reduced ejection fraction (HFrEF) treatment targets neurohormonal inhibition; however, our experimental observations and the recent clinical evidence in myocardial infarction and heart transplant patients support the anti-inflammatory pathway as a potential novel therapeutic target. Therefore, we aimed to assess the safety of human monoclonal antibody-CD20 (rituximab) in patients with HFrEF.

METHODS AND ANALYSIS

We designed this protocol according to the Standard Protocol Items: Recommendations for Interventional Trials guidelines as a phase II, single-centred, single group and prospective clinical trial. We hypothesise that the use of a monoclonal antibody, rituximab, could be a potentially safe new agent in HFrEF management. We will include patients with EF≤40%, New York Heart Association functional class III/IV and unresponsive to standard treatment. We will use a dosing regimen (1000 mg) previously applied to post-transplant patients and patients with rheumatoid arthritis with favourable results, aiming to provide supplementary evidence of safety in patients with HFrEF. We designed strategies tailored to preserving the integrity of patient safety. The date of study initiation will be 29th of May 2019.

ETHICS AND DISSEMINATION

The following protocol was approved by IRB committees, and as a requirement, all patients need to sign an informed consent form before being subjected to any procedure prior to the initiation of the study. We are aware that the trial will be run in patients who due to their cardiovascular functional class, have reserved prognosis, with no known therapy that leads to improvement. Hence, this trial searches to establish the safety of an alternative strategy in ameliorating prognosis. Regardless of the study outcomes, whether favourable or not, they will be published. If a favourable outcome is evidenced, it will prompt performing a phase III, efficacy-based study.

TRIAL REGISTRATION NUMBER

The trial was approved by the IRB (CONBIOÉTICA-19-CEI-011-20161017 and COFEPRIS-17-CI-19-039-003), and registered at Clinicaltrials.gov (NCT03332888; Pre-Results).

Autoimmune Thrombotic Thrombocytopenic Purpura: Two Rare Cases Associated with Juvenile Idiopathic Arthritis and Multiple Sclerosis

Secondary thrombotic microangiopathies are associated with several underlying conditions, with most of them being resolved after the treatment of background disease. Thrombotic thrombocytopenic purpura (TTP) is a rare microangiopathy presenting with anemia, thrombocytopenia, and neurological deficits, occurring most often in various autoimmune diseases due to inhibition of ADAMTS13 by autoantibodies, as well as in pregnant women with or without an autoimmune substrate. In this article, we report two newly diagnosed TTP cases, who have not been published so far. The first is a 27-year-old woman with a history of polyarticular rheumatoid factor negative juvenile idiopathic arthritis, who presented with thrombocytopenia, anemia, schistocytes on blood smear, headache, and active arthritis. Originally she was treated successfully with plasma exchange, intravenous prednisone, and vincristine, and a few months after the TTP episode, she was commenced on rituximab, resulting in remission of primary disease and no relapse of TTP. The second case refers to a 29-year-old pregnant woman complaining of dizziness and fatigue with microangiopathic hemolytic anemia. She was treated with plasma exchanges, intravenous prednisolone, and INN human normal immunoglobulin with full remission of the TTP episode. Six and half years later, she was diagnosed with multiple sclerosis and was commenced on interferon beta-1 alpha, with no recurrent episode of TTP. These cases broaden the spectrum of autoimmune disorders manifested or complicated clinically by TTP. Furthermore, biological agents such as rituximab appear to be an effective treatment option for refractory cases of TTP related to systemic rheumatic disease, indicating an alternative therapeutic solution in persistent cases of this disorder.

Thrombotic Microangiopathy Care Pathway: A Consensus Statement for the Mayo Clinic Complement Alternative Pathway-Thrombotic Microangiopathy (CAP-TMA) Disease-Oriented Group

Thrombotic microangiopathies (TMAs) comprise a heterogeneous set of conditions linked by a common histopathologic finding of endothelial damage resulting in microvascular thromboses and potentially serious complications. The typical clinical presentation is microangiopathic hemolytic anemia accompanied by thrombocytopenia with varying degrees of organ ischemia. The differential diagnoses are generally broad, while the workup is frequently complex and can be confusing. This statement represents the joint recommendations from a multidisciplinary team of Mayo Clinic physicians specializing in the management of TMA. It comprises a series of evidence- and consensus-based clinical pathways developed to allow a uniform approach to the spectrum of care including when to suspect TMA, what differential diagnoses to consider, which diagnostic tests to order, and how to provide initial empiric therapy, as well as some guidance on subsequent management.

Clopidogrel-induced refractory thrombotic thrombocytopenic purpura successfully treated with rituximab

Thrombotic thrombocytopenic purpura (TTP) is a multisystem disorder characterized by microvascular aggregation of platelets and fibrin strands causing thrombocytopenia, microangiopathic hemolytic anemia, and organ dysfunction. TTP can develop as a result of a deficiency in ADAMTS13 enzyme activity due to either a genetic defect or, more commonly, the development of anti-ADAMTS13 autoantibodies. TTP can also be associated with pregnancy, organ transplant, lupus, infections, and drugs. Here, we present a case of TTP that developed shortly after the start of clopidogrel treatment for acute ischemic stroke and acute myocardial infarction, and describe the clinical presentation, refractory course of the disease, and successful induction of remission through the use of rituximab in a setting of pre-existing autoimmune diseases.