Assessment of epidemiology and outcomes of adult patients with kidney-limited thrombotic microangiopathies.

Thrombotic microangiopathies (TMA) are usually associated with hematological features (RH-TMA). The epidemiology of TMA limited to kidneys (RL-TMA) is unclear Therefore, patients with TMA and native kidney biopsies were identified during 2009-2022 in 20 French hospitals and results evaluated. RL-TMA was present in 341/757 (45%) patients and associated with lower creatinine levels (median 184 vs 346 µmol/L) than RH-TMA. RL-TMA resulted from virtually all identified causes, more frequently from anti-VEGF treatment and hematological malignancies but less frequently from shigatoxin-associated hemolytic uremic syndrome (HUS), systemic sclerosis, gemcitabine and bacterial infection, and even less frequently when three or more causes/triggers were combined (RL-TMA: 5%; RH-TMA: 12%). RL-TMA was associated with significantly lower major cardiovascular events (10% vs 20%), kidney replacement therapy (23% vs 43%) and death (12% vs 20%) than RH-TMA during follow-up (median 28 months). Atypical HUS (aHUS) was found in 326 patients (RL-TMA: 43%, RH-TMA: 44%). Among the 69 patients with proven complement-mediated aHUS, eculizumab (anti-C5 therapy) was used in 43 (62%) (RL-TMA: 35%; RH-TMA: 71%). Among the 257 other patients with aHUS, including 51% with RL-TMA, eculizumab was used in 29 but with unclear effects of this treatment. Thus, RL-TMA represents a very high proportion of patients with TMA and results from virtually all known causes of TMA and includes 25% of patients with complement-mediated aHUS. Adverse outcomes of RL-TMA are lower compared to RH-TMA but remain significant. Anti-C5 therapy was rarely used in RL-TMA, even in proven complement-mediated aHUS, and its effects remain to be assessed.

Eculizumab dose tapering should take into account the nonlinearity of its pharmacokinetics.

AIMS: Eculizumab is a monoclonal antibody targeting complement protein C5 used in renal diseases. As recommended dosing regimen leads to unnecessarily high concentrations in some patients, tailored dosing therapeutic drug monitoring was proposed to reduce treatment cost. The objectives of the present work were (i) to investigate the target-mediated elimination of eculizumab and (ii) whether a pharmacokinetic model integrating a nonlinear elimination allows a better prediction of eculizumab concentrations than a linear model. METHODS: We analysed 377 eculizumab serum concentrations from 44 patients treated for atypical haemolytic uraemic syndrome and C3 glomerulopathy with a population pharmacokinetic approach. Critical concentrations (below which a non-log-linear decline of concentration over time is evidenced) were computed to estimate the relevance of the target-mediated elimination. Simulations of dosing regimens were then performed to predict probabilities of target attainment (i.e. trough >100 mg/L). RESULTS: Pharmacokinetics of eculizumab was nonlinear and followed a mixture of first-order (CL = 1.318 mL/day/kg) and Michaelis-Menten elimination (Vmax = 26.07 mg/day, Km = 24.06 mg/L). Volume of distribution (72.39 mL/kg) and clearance were weight-dependent. Critical concentrations (Vmax/CL) ranged from 144.7 to 759.7 mg/L and were inversely related to body weight (P = .013). Nonlinearity was thus noticeable at therapeutic concentrations. Simulations predicted that 1200 mg of eculizumab every 21 days would allow 85% and 76% of patients to maintain a therapeutic exposure, for 50 or 90 kg body weight, respectively. CONCLUSIONS: Our study investigates the nonlinear elimination of eculizumab and discusses the importance of accounting for eculizumab target-mediated elimination in therapeutic drug monitoring.

Pharmacokinetics of eculizumab in adult and pediatric patients with atypical hemolytic uremic syndrome and C3 glomerulopathy. / Farmacocinética de eculizumab en pacientes adultos y pediátricos con síndrome hemolítico urémico atípico y glomerulopatía C3.

OBJECTIVE: The objective of the study was to analyze and describe the concentrations of eculizumab and the complement blockade in patients with atypical hemolytic uremic syndrome (aHUS) and C3 glomerulopathy, and to define a therapeutic margin where there is a high probability of achieving therapeutic efficacy. METHODS: Observational, ambispective and multicenter study that included adult and pediatric patients diagnosed with aHUS and C3 glomerulopathy from September 2020 to October 2022 in five hospitals in Spain. Eculizumab was administered at the doses recommended by the data sheet according to the European Medicines Agency (EMA). Pre-dose and post-dose concentrations of eculizumab were determined, as well as blockade of the classical complement pathway (CH50). Sociodemographic and clinical data were collected, and pharmacokinetic parameters were calculated. To establish the cut-off point for eculizumab concentrations that predicted complement blockade, Receiver Operating Characteristic (ROC) curve analysis was performed. Lastly, the Kruskal-Wallis test was used to contrast the differences in different parameters according to eculizumab concentrations. RESULTS: Twenty-five patients were included, 19 adults (76.0%) and 6 pediatrics (24.0%), with median ages of 43.4 (IQR 35.7-48.8) and 10.1 (IQR 9.6-11.3) years, respectively. Of these, 22 (88.0%) patients were diagnosed with aHUS and 3 (12.0%) with C3 glomerulopathy. A total of 111 eculizumab concentrations were determined. Mean pre-dose and post-dose concentration values detected during the maintenance phase were 243.8 (SD 240.6) µg/mL and 747.4 (SD 444.3) µg/mL, respectively. Increased complement blockade was observed at higher pre-dose concentrations (p=0.002) and decreased serum creatinine at both higher pre- and post-dose concentrations (p=0.001 and p=0.017, respectively). Using ROC curves, it was determined that a pre-dose concentration >149.0 µg/mL was optimal to achieve complement blockade, with an AUC of 0.87 (0.78-0.95). Finally, high inter-individual (48.9% CV) with low intra-individual variabilities (11.9% CV) in eculizumab clearance were observed. CONCLUSIONS: The present study reports supratherapeutic concentrations of eculizumab in patients with aHUS, and defines higher concentrations than those described in the data sheet to achieve blockade, thus encouraging the personalization of treatment with eculizumab.

[Translated article] Pharmacokinetics of eculizumab in adult and pediatric patients with atypical hemolytic uremic syndrome and C3 glomerulopathy.

OBJECTIVE: The objective of the study was to analyze and describe the concentrations of eculizumab and the complement blockade in patients with atypical hemolytic uremic syndrome (aHUS) and C3 glomerulopathy, and to define a therapeutic margin where there is a high probability of achieving therapeutic efficacy. METHODS: Observational, ambispective, and multicenter study that included adult and pediatric patients diagnosed with aHUS and C3 glomerulopathy from September 2020 to October 2022 in 5 hospitals in Spain. Eculizumab was administered at the doses recommended by the data sheet according to the European Medicines Agency (EMA). Pre- and post-dose concentrations of eculizumab were determined, as well as blockade of the classical complement pathway (CH50). Sociodemographic and clinical data were collected, and pharmacokinetic parameters were calculated. To establish the cut-off point for eculizumab concentrations that predicted complement blockade, Receiver Operating Characteristic (ROC) curve analysis was performed. Lastly, the Kruskal-Wallis test was used to contrast the differences in different parameters according to eculizumab concentrations. RESULTS: Twenty-five patients were included, 19 adults (76.0%) and 6 pediatrics (24.0%), with median ages of 43.4 (interquartile range (IQR) 35.7-48.8) and 10.1 (IQR 9.6-11.3) years, respectively. Of these, 22 (88.0%) patients were diagnosed with aHUS and 3 (12.0%) with C3 glomerulopathy. A total of 111 eculizumab concentrations were determined. Mean pre- and post-dose concentration values detected during the maintenance phase were 243.8 (SD 240.6) µg/mL and 747.4 (standard deviation (SD) 444.3) µg/mL, respectively. Increased complement blockade was observed at higher pre-dose concentrations (P = .002) and decreased serum creatinine at both higher pre- and post-dose concentrations (P = .001 and P = .017, respectively). Using ROC curves, it was determined that a pre-dose concentration >149.0 µg/mL was optimal to achieve complement blockade, with an AUC of 0.87 (0.78-0.95). Finally, high inter-individual (48.9% variation coefficient (CV)) with low intra-individual variabilities (11.9% CV) in eculizumab clearance were observed. CONCLUSIONS: The present study reports supratherapeutic concentrations of eculizumab in patients with aHUS, and defines higher concentrations than those described in the data sheet to achieve blockade, thus encouraging the personalization of treatment with eculizumab.

Complement inhibitors in pediatric kidney diseases: new therapeutic opportunities.

Historically, the complement system (classical, lectin, alternative, and terminal pathways) is known to play a crucial role in the etiopathogenesis of many kidney diseases. Direct or indirect activation in these settings is revealed by consumption of complement proteins at the serum level and kidney tissue deposition seen by immunofluorescence and electron microscopy. The advent of eculizumab has shown that complement inhibitors may improve the natural history of certain kidney diseases. Since then, the number of available therapeutic molecules and experimental studies on complement inhibition has increased exponentially. In our narrative review, we give a summary of the main complement inhibitors that have completed phase II and phase III studies or are currently used in adult and pediatric nephrology. The relevant full-text works, abstracts, and ongoing trials (clinicaltrials.gov site) are discussed. Data and key clinical features are reported for eculizumab, ravulizumab, crovalimab, avacopan, danicopan, iptacopan, pegcetacoplan, and narsoplimab. Many of these molecules have been shown to be effective in reducing proteinuria and stabilizing kidney function in different complement-mediated kidney diseases. Thanks to their efficacy and target specificity, these novel drugs may radically improve the outcome of complement-mediated kidney diseases, contributing to an improvement in our understanding of their underlying pathophysiology.

Complement-mediated thrombotic microangiopathy treated with anticomplement protein 5 therapy, a retrospective study.

BACKGROUND: Complement-mediated thrombotic microangiopathy (CM-TMA), also called atypical hemolytic uremic syndrome (aHUS), is a difficult-to-diagnose rare disease that carries severe morbidity and mortality. Anti-C5 monoclonal antibodies (aC5-mab) are standard treatments, but large studies and long-term data are scarce. Here, we report our single institution experience to augment the knowledge of CM-TMA treated with aC5-mab therapy. METHODS: We aimed to assess the short and long-term effects of aC5-mab in patients diagnosed with CM-TMA treated outside of a clinical trial. This was a retrospective study. We included all patients diagnosed with CM-TMA and treated with aC5-mab at our institution. There were no exclusion criteria. Endpoints included complete TMA response (CR) defined as normalization of hematological parameters and ≥25% improvement in serum creatinine (Cr) from baseline in patients with renal disease, relapse defined as losing the previously achieved CR, morbidity, adverse events, and survival. RESULTS: We found 28 patients with CM-TMA treated with aC5-mab. The median age was 50 years. Baseline laboratories: platelet counts 93 × 109 /L, hemoglobin 8.6 g/dL, lactate dehydrogenase 1326 U/L, serum Cr 4.7 mg/dL, and estimated glomerular filtration rate 19 mL/min. One individual was on renal replacement therapy (RRT) and 10 initiated RRT within 5 days of the first dose of aC5-mab. Genetic variants associated with CM-TMA included mutations in C3, CFB, CFH, CFHR1/3, CFI, and MCP. The mean duration of hospitalization was 24 days. The median time to initiation of aC5-mab was 10 days. Sixteen subjects received RRT. At the time of hospital discharge, 27 were alive, 14 remained on RRT, and 4 had a CR. At 6 months, 23 patients were alive, 18 continued aC5-mab, 8 remained on RRT, and 9 had a CR. At the last follow-up visit past 6 months, 20 were alive, 14 continued aC5-mab, 5 remained on RRT, 12 had a CR, and 1 was lost to follow-up. CONCLUSIONS: Our study provides real-world experience and insight into the long-term outcomes of CM-TMA treated with aC5-mab. Our findings validate that CM-TMA is an aggressive disease with significant morbidity and mortality, and confirm that aC5-mab is a relatively effective therapy for CM-TMA. Our study adds practical, real-world experience to the literature, but future research remains imperative.

Atypical hemolytic and uremic syndrome in Algeria: diagnostic difficulties and therapeutic constraints / Syndrome hémolytique et urémique atypique en Algérie : difficultés diagnostiques et contraintes thérapeutiques

Atypical Hemolytic Uremic Syndrome (aHUS) is a systemic disease due to dysregulation of the alternate complement pathway, mortality is estimated at 10% and more than 50% of patients progress to end-stage renal disease. The aim of this study was to summarize the clinical data and biological results as well as the evolution and management of patients with aHUS seen over a period of four years in one specialized department in Algeria. Our study was observational and longitudinal. The inclusion criteria were: the clinical-biological triad of aHUS and age ≤ 16 years. The type of treatment, the presence of complement mutation or anti-complement factor autoantibodies were not eligibility conditions. On inclusion and every six months, demographic data, clinical and biological history and results after treatment were collected prospectively. Our workforce consisted of 21 children with aHUS. Thirteen patients benefited from a complement study; among them, 7 had complement abnormalities. Eleven children had familial HUS; among them 8 died and 6 were less than one year old. Plasma exchanges were performed in two children. Six patients received eculizumab, with an average age of 3.6 years. After the acute phase, 9 children recovered their kidney function, one child had developed a chronic kidney disease (CKD), and 11 died, among them 8 belong to aHUS families. Fifty percent of deaths occurred in the first 3 months. At 2 years of evolution, out of 7 children having reached this stage, five had renal sequelae and four of them had CKD. The severe prognosis of this disease makes early diagnosis and treatment essential.

Le syndrome hémolytique et urémique atypique (SHUa) est une maladie systémique due à une dérégulation de la voie alterne du complément. La mortalité est estimée à 10 % et plus de 50 % des patients évoluent vers l'insuffisance rénale terminale. Le but de la présente étude était de résumer les données cliniques et les résultats biologiques ainsi que l'évolution et la prise en charge des patients atteints de SHUa vus sur une durée de quatre ans dans un service spécialisé en Algérie. Notre étude était observationnelle et longitudinale. Les critères d'inclusion étaient : la triade clinico-biologique du SHUa et l'âge ≤ 16 ans. Le type de traitement, la présence de mutation du complément ou d'auto-anticorps anti-facteur du complément ne constituaient pas des conditions d'éligibilité. À l'inclusion et tous les six mois, les données démographiques, l'histoire clinique, biologique et les résultats après traitement étaient collectés prospectivement. Notre effectif était formé de 21 enfants avec SHUa. Treize patients ont bénéficié d'une étude du complément ; parmi eux sept avaient des anomalies du complément. Onze enfants avaient un SHU familial ; parmi eux huit sont décédés et six avaient moins d'un an. Des échanges plasmatiques ont été réalisés chez deux enfants. Six patients ont bénéficié d'éculizumab, avec un âge moyen de 3,6 ans. Après la phase aiguë, neuf enfants avaient récupéré leur fonction rénale, un enfant avait gardé une insuffisance rénale chronique (IRC), et 11 enfants étaient décédés dont huit appartenaient à des familles de SHUa. Cinquante pourcent des décès étaient survenus durant les trois premiers mois. À deux ans d'évolution, sur sept enfants ayant atteint ce stade, cinq avaient des séquelles rénales et quatre d'entre eux étaient en IRC. Le pronostic sévère de cette maladie rend la précocité du diagnostic et de la prise en charge primordiales.

Functional similarity of ABP 959 and eculizumab in simulated serum models of aHUS and NMOSD.

ABP 959 is being developed as a biosimilar to Soliris® (eculizumab) reference product (RP), which was approved under orphan designation for a group of rare diseases including paroxysmal nocturnal hemoglobinuria (PNH), atypical hemolytic uremic syndrome (aHUS), generalized myasthenia gravis (gMG), and neuromyelitis optica spectrum disorder (NMOSD). Development of biosimilars for therapeutics approved for rare disease indications must provide scientific rationale based on the totality of evidence (TOE). To support the TOE and the scientific justification for extrapolation to all approved indications for eculizumab RP, including but not limited to aHUS and NMOSD, we utilized simulated ex-vivo pharmacodynamic (PD) assessments to compare the complement component 5 (C5) inhibitory activity of ABP 959 and the RP. Hemolysis activity of CH50 and AH50, and Wieslab CP, AP, and LP endpoints represent the three complement activation pathways (classical, alternative, and lectin), all of which share the terminal pathway and require C5 for activity. These endpoints were evaluated in normal serum, simulated aHUS serum, and simulated NMOSD serum to provide a robust comparison. The results support the conclusion that ABP 959 and eculizumab RP exhibit highly similar inhibition of C5 function regardless of the type of serum used. This work presents a full comparison of the effect of C5 inhibition across five complement functional assays. Using this approach to confirm functional similarity of ABP 959 with eculizumab RP contributes to the TOE for biosimilarity and provides support for extrapolation based on inhibition of C5 function to other rare disease indications approved for eculizumab RP.

The Rationale of Complement Blockade of the MCPggaac Haplotype following Atypical Hemolytic Uremic Syndrome of Three Southeastern European Countries with a Literature Review.

We present eight cases of the homozygous MCPggaac haplotype, which is considered to increase the likelihood and severity of atypical hemolytic uremic syndrome (aHUS), especially in combination with additional risk aHUS mutations. Complement blockade (CBT) was applied at a median age of 92 months (IQR 36-252 months). The median number of relapses before CBT initiation (Eculizumab) was two. Relapses occurred within an average of 22.16 months (median 17.5, minimum 8 months, and maximum 48 months) from the first subsequent onset of the disease (6/8 patients). All cases were treated with PI/PEX, and rarely with renal replacement therapy (RRT). When complement blockade was applied, children had no further disease relapses. Children with MCPggaac haplotype with/without additional gene mutations can achieve remission through renal replacement therapy without an immediate need for complement blockade. If relapse of aHUS occurs soon after disease onset or relapses are repeated frequently, a permanent complement blockade is required. However, the duration of such a blockade remains uncertain. If complement inhibition is not applied within 4-5 relapses, proteinuria and chronic renal failure will eventually occur.

New findings in preventing recurrence and improving renal function in AHUS patients after renal transplantation treated with eculizumab: a systemic review and meta-analyses.

BACKGROUND: The long-term mortality of kidney transplantation patients with atypical hemolytic uremic syndrome remains high, and the efficacy of the main treatment eculizumab is still controversial. OBJECTIVE: A comprehensive systematic review and meta-analysis of clinical trials using eculizumab in renal transplant patients with atypical hemolytic uremic syndrome was conducted to evaluate the efficacy of this therapy and its impact on renal function. METHODS: A comprehensive systematic search was conducted across multiple reputable databases, including Ovid (MEDLINE, EMBASE), PubMed, and the Cochrane Library (since database inception), to identify relevant studies exploring the use of eculizumab in patients with atypical hemolytic uremic kidney transplantation. Various renal function parameters, such as dialysis, rejection, glomerular filtration rate, serum creatinine, lactate dehydrogenase, and platelet count, along with patient relapse rates, were extracted and summarized using a combination of robust statistical methods, including fixed effects, random effects, and general inverse variance methods. RESULT: Eighteen trials with 618 subjects were analyzed. Our analysis suggests that the use of eculizumab is associated with a reduced likelihood of AHUS recurrence (odds ratio (OR) = 0.05, 95% CI: 0.00-0.13), as well as a significant reduction in the need for dialysis (odds ratio (OR) = 0.13, 95% CI: 0.01-0.32). Additionally, eculizumab treatment led to lower serum creatinine levels (mean differences (MD) = 126.931µmoI/L, 95% CI: 115.572µmoI/L-138.290µmoI/L) and an improved glomerular filtration rate (mean differences (MD) = 59.571 ml/min, 95% CI: 57.876 ml/min-61.266 mL/min). Our results also indicate that the use of eculizumab reduces the likelihood of rejection (odds ratio (OR) = 0.09, 95% CI: 0.01-0.22). Furthermore, the drug was effective in improving platelet counts (×10∧9/L) (mean differences (MD) = 163.421, 95% CI: 46.998-279.844) and lactate dehydrogenase levels (mean differences (MD) = 336.608 U/L, 95% CI: 164.816 U/L-508.399 U/L). CONCLUSIONS: Based on the meta-analysis, treatment with eculizumab can reduce dialysis rates and improve patients' quality of life by enhancing renal function.

Complement Factor I Gene Variant in an Atypical Hemolytic Uremic Syndrome Triggered by Hypereosinophilia Syndrome.

Atypical hemolytic uremic syndrome (aHUS) is a condition characterized by acute kidney injury (AKI), thrombocytopenia, and microangiopathic hemolytic anemia secondary to complement pathway dysregulation. Several triggers have been identified as causing aHUS in genetically susceptible patients; however, hypereosinophilia syndrome (HES)-triggered aHUS has not been reported. In this article, we present a case of aHUS presented with generalized urticarial rashes and angioedema. The initial investigations revealed hypereosinophilia (maximal absolute eosinophil count of 6,840 cells/µL) with normal bone-marrow analyses; hence, idiopathic HES was diagnosed. During hospitalization, the patient developed convulsion, stuporous, and full-blown thrombotic microangiopathy (TMA), with AKI requiring temporary hemodialysis. A kidney biopsy confirmed the existence of renal TMA. Next-generation sequencing of the coding regions of aHUS-related genes was performed, revealing an underlying complement factor I (CFI) deficiency, a heterozygous variant p.P64L of CFI gene. The patient was successfully treated with high-dose steroids and extended duration of plasmapheresis.

Treatment preference and quality of life impact: ravulizumab vs eculizumab for atypical hemolytic uremic syndrome.

Aim: Ravulizumab and eculizumab are complement C5 inhibitors approved for the treatment of atypical hemolytic uremic syndrome (aHUS). Ravulizumab requires less frequent infusions than eculizumab, which may reduce treatment burden. This study investigated patients' treatment preferences and the impact of both treatments on patient and caregiver quality of life. Materials & methods: Two surveys were conducted (one for adult patients with aHUS and one for caregivers of pediatric patients with aHUS) to quantitatively assess treatment preference and the patient- and caregiver-reported impact of ravulizumab and eculizumab on quality of life. Patients were required to have a diagnosis of aHUS, to be currently receiving treatment with ravulizumab and to have received prior treatment with eculizumab. Participants were recruited via various sources: the Alexion OneSource™ patient support program, the Rare Patient Voice recruitment agency, the aHUS Foundation and directly via a clinician involved in the study. Results: In total, 50 adult patients (mean age: 46.5 years) and 16 caregivers of pediatric patients (mean age: 10.1 years) completed the surveys. Most adult patients (94.0%) and all caregivers reported an overall preference for ravulizumab over eculizumab; infusion frequency was one of the main factors for patients when selecting their preferred treatment. Fewer patients reported disruption to daily life and the ability to go to work/school due to ravulizumab infusion frequency (4.0% and 5.7%, respectively) than eculizumab infusion frequency (72.0% and 60.0%), with similar results for caregivers. Conclusion: Adult patients and caregivers of pediatric patients indicated an overall preference for ravulizumab than eculizumab for the treatment of aHUS, driven primarily by infusion frequency. This study contributes to the emerging real-world evidence on the treatment impact and preference in patients with aHUS.

Real-world safety profile of eculizumab in patients with paroxysmal nocturnal hemoglobinuria, atypical hemolytic uremic syndrome, or generalized myasthenia gravis: an integrated analysis of post-marketing surveillance in Japan.

Eculizumab is a C5 inhibitor approved for the treatment of paroxysmal nocturnal hemoglobinuria (PNH), atypical hemolytic uremic syndrome (aHUS), and anti-acetylcholine receptor antibody-positive generalized myasthenia gravis (AChR + gMG) in Japan. We report integrated safety data from post-marketing surveillance in these three indications, focusing on commonly occurring adverse events (AEs) and infection-related AEs. Of 1219 patients registered, 1055 (PNH: 780; aHUS: 192; AChR + gMG: 83) had available safety data. Total eculizumab exposure was 3977.361 patient-years. AEs were reported in 74.03% of patients. AEs with an incidence of  ≥ 1.0 per 100 patient-years included hemolysis, headache, nasopharyngitis, renal impairment, anemia, pneumonia, upper respiratory tract inflammation, influenza, condition aggravated, and infection. The incidence of infection-related AEs was 21.30 per 100 patient-years, the most frequent types (≥ 1.0 per 100 patient-years) being nasopharyngitis, pneumonia, influenza, and infection. Meningococcal infections were reported in four patients (0.10 per 100 patient-years). Two patients died from meningococcal sepsis, with a mortality rate of 0.05 per 100 patient-years. This is the largest safety dataset on eculizumab in Japan derived from more than 10 years of clinical experience. No new safety signals were observed and the safety profile of eculizumab was consistent with that in previous clinical trials and international real-world safety analyses.

Purtscher-Like Retinopathy Associated With Atypical Hemolytic Uremic Syndrome.

This case report discusses a diagnosis of atypical hemolytic uremic syndrome in a woman aged 38 years who presented with progressively blurry vision in both eyes over a period of 10 days.

Eculizumab use in patients with pneumococcal-associated hemolytic uremic syndrome and kidney outcomes.

BACKGROUND: Streptococcus pneumoniae-associated hemolytic uremic syndrome (P-HUS) is a rare and severe disease. Only a few reports have been published about eculizumab use in P-HUS. METHODS: We analyzed demographic, clinical, and laboratory data of patients with P-HUS from our center. RESULTS: The cohort consisted of 4 females and 3 males. All patients had pneumonia. Four were given eculizumab (days 1-3). The eculizumab group required a shorter duration of dialysis and mechanical ventilation (medians 20 vs. 28.5 and 30 vs 38.5 days, respectively) compared with the non-eculizumab group, but this was still much longer than normally reported; the thrombocytopenia resolution was similar in both groups (medians 10 vs. 8 days). Chronic kidney disease (CKD) was correlated with the duration of dialysis and mechanical ventilation duration at 1 year (r = 0.797, P = 0.032 and r = 0.765, P = 0.045) and last follow-up (r = 0.807, P = 0.028 and r = 0.814, P = 0.026, respectively); our scoring system showed even stronger correlations (r = 0.872, P = 0.011 and r = 0.901, P = 0.0057, respectively). The eculizumab group showed slightly better 1-year and last follow-up CKD stage (2.75 vs. 3, P = 0.879 and 2.5 vs. 3.67, P = 0.517). CONCLUSIONS: Despite the fact that the eculizumab group showed better outcomes, eculizumab does not seem to improve the course of P-HUS compared with previous reports. Kidney outcomes are strongly correlated with the duration of dialysis and mechanical ventilation duration. A higher resolution version of the Graphical abstract is available as Supplementary information.

Molecular pharmacology in complement-mediated hemolytic disorders.

In the last decade, a deeper understanding of the pathogenesis of complement mediated hemolytic disorders, such as paroxysmal nocturnal hemoglobinuria (PNH), cold agglutinin disease (CAD), warm type autoimmune hemolytic anemia (AIHA) with complement activation (wAIHA), and atypical hemolytic uremic syndrome (aHUS), paved the way to the therapeutic shift from purely supportive approaches to complement-targeted therapies. This resulted in a significant improvement in disease management, survival, and quality of life. In this review, we will provide a snapshot of novel therapies for complement-mediated hemolytic anemias with a focus on those ready to use in clinical practice. C5 inhibitors eculizumab and the long-acting ravulizumab, are the established gold standard for untreated PNH patients, whilst the C3 inhibitor pegcetacoplan should be considered for suboptimal responders to anti-C5 drugs. Several additional compounds targeting the complement cascade at different levels (other C5 inhibitors, factor B and D inhibitors) are under active investigation with promising results. In CAD, immunosuppression with rituximab remains the first-line. However, recently FDA and EMA approved the anti-C1s monoclonal antibody, sutimlimab, that showed dramatic responses and whose regulatory approval is soon awaited in many countries. Other drugs under investigation in AIHA include the C3 inhibitor pegcetacoplan, and the anti-C1q ANX005 for warm AIHA with complement activation. Finally, aHUS is an indication for complement inhibitors. Eculizumab and ravulizumab have been approved, whilst other C5 inhibitors, and novel lectin pathway inhibitors are under active investigation in this disease.

Efficacy and Safety of Eculizumab in Pediatric Patients Affected by Shiga Toxin-Related Hemolytic and Uremic Syndrome: A Randomized, Placebo-Controlled Trial.

SIGNIFICANCE STATEMENT: Shiga toxin-related hemolytic uremic syndrome (STEC-HUS) is a serious condition, characterized by multiorgan thrombotic microangiopathy, mainly affecting children. Renal involvement is severe, with approximately half of patients requiring dialysis. So far, no specific treatment has been proven efficient in STEC-HUS. The use of eculizumab, a monoclonal antibody inhibiting terminal complement complex, has demonstrated remarkable success in atypical hemolytic uremic syndrome, but its use in uncontrolled studies to treat STEC-HUS has yielded inconsistent results. In this Phase 3 randomized, placebo-controlled trial in 100 pediatric patients with STEC-HUS, the findings did not show efficacy of eculizumab during the acute phase of the disease. However, the results indicated a reduction of renal sequelae in eculizumab-treated patients at 1-year follow-up. Larger prospective studies would be needed to further explore eculizumab as a potential treatment. BACKGROUND: Shiga toxin-related hemolytic uremic syndrome (STEC-HUS) in children is a severe condition, resulting in approximately 50% of patients requiring RRT. Furthermore, at least 30% of survivors experience kidney sequelae. Recently, activation of the complement alternative pathway has been postulated as a factor in STEC-HUS pathophysiology, leading to compassionate use of eculizumab, a monoclonal antibody inhibiting the terminal complement complex, in affected patients. Given the lack of therapy for STEC-HUS, a controlled study of eculizumab efficacy in treating this condition is a priority. METHODS: We conducted a Phase 3 randomized trial of eculizumab in children with STEC-HUS. Patients were randomly assigned in a 1:1 ratio to receive either eculizumab or placebo during 4 weeks. Follow-up lasted for 1 year. The primary end point was RRT duration <48 hours after randomization. Secondary endpoints included hematologic and extrarenal involvement. RESULTS: Baseline characteristics were similar among the 100 patients who underwent randomization. The rate of RRT <48 hours did not differ significantly between the two groups (48% in the placebo versus 38% in the eculizumab group; P = 0.31) or in the course of ARF. The two groups also exhibited similar hematologic evolution and extrarenal manifestations of STEC-HUS. The proportion of patients experiencing renal sequelae at 1 year was lower in the eculizumab group than in the placebo group (43.48% and 64.44%, respectively, P = 0.04). No safety concern was reported. CONCLUSIONS: In pediatric patients with STEC-HUS, eculizumab treatment does not appear to be associated with improved renal outcome during acute phase of the disease but may reduce long-term kidney sequelae. CLINICAL TRIALS REGISTRATIONS: EUDRACT (2014-001169-28) ClinicalTrials.gov ( NCT02205541 ).

Atypical hemolytic uremic syndrome in the era of terminal complement inhibition: an observational cohort study.

Historically, the majority of patients with complement-mediated atypical hemolytic uremic syndrome (CaHUS) progress to end-stage kidney disease (ESKD). Single-arm trials of eculizumab with a short follow-up suggested efficacy. We prove, for the first time to our knowledge, in a genotype matched CaHUS cohort that the 5-year cumulative estimate of ESKD-free survival improved from 39.5% in a control cohort to 85.5% in the eculizumab-treated cohort (hazard ratio, 4.95; 95% confidence interval [CI], 2.75-8.90; P = .000; number needed to treat, 2.17 [95% CI, 1.81-2.73]). The outcome of eculizumab treatment is associated with the underlying genotype. Lower serum creatinine, lower platelet count, lower blood pressure, and younger age at presentation as well as shorter time between presentation and the first dose of eculizumab were associated with estimated glomerular filtration rate >60 ml/min at 6 months in multivariate analysis. The rate of meningococcal infection in the treated cohort was 550 times greater than the background rate in the general population. The relapse rate upon eculizumab withdrawal was 1 per 9.5 person years for patients with a pathogenic mutation and 1 per 10.8 person years for those with a variant of uncertain significance. No relapses were recorded in 67.3 person years off eculizumab in those with no rare genetic variants. Eculizumab was restarted in 6 individuals with functioning kidneys in whom it had been stopped, with no individual progressing to ESKD. We demonstrated that biallelic pathogenic mutations in RNA-processing genes, including EXOSC3, encoding an essential part of the RNA exosome, cause eculizumab nonresponsive aHUS. Recessive HSD11B2 mutations causing apparent mineralocorticoid excess may also present with thrombotic microangiopathy.