Efficacy and safety of lumasiran for infants and young children with primary hyperoxaluria type 1: 30-month analysis of the phase 3 ILLUMINATE-B trial.

Background: Primary hyperoxaluria type 1 (PH1) is a genetic disorder resulting in overproduction of hepatic oxalate, potentially leading to recurrent kidney stones, nephrocalcinosis, chronic kidney disease, and kidney failure. Lumasiran, the first RNA interference therapeutic approved for infants and young children, is a liver-directed treatment that reduces hepatic oxalate production. Lumasiran demonstrated sustained efficacy with an acceptable safety profile over 12 months in infants and young children (age <6 years) with PH1 in ILLUMINATE-B (clinicaltrials.gov: NCT03905694), an ongoing, Phase 3, multinational, open-label, single-arm study. Methods: Here, we report interim efficacy and safety findings from ILLUMINATE-B following 30 months of lumasiran treatment. Eligible patients had an estimated glomerular filtration rate (eGFR) >45 ml/min/1.73 m2 if ≥12 months old or normal serum creatinine if <12 months old, and a urinary oxalate to creatinine ratio (UOx:Cr) greater than the upper limit of normal. All 18 patients enrolled in ILLUMINATE-B completed the 6-month primary analysis period, entered an extension period of up to 54 months, and continue to participate in the study. Results: At Month 30, mean percent change from baseline in spot UOx:Cr was -76%, and mean percent change in plasma oxalate was -42%. eGFR remained stable through Month 30. In 14 patients (86%) with nephrocalcinosis at baseline, nephrocalcinosis grade improved at Month 24 in 12; no patient worsened. In the 4 patients without baseline nephrocalcinosis, nephrocalcinosis was absent at Month 24. Kidney stone event rates were ≤0.25 per person-year through Month 30. Mild, transient injection site reactions were the most common lumasiran-related adverse events (17% of patients). Conclusion: In infants and young children with PH1, long-term lumasiran treatment resulted in sustained reductions in urinary and plasma oxalate that were sustained for 30 months, with an acceptable safety profile. Kidney function remained stable, low kidney stone event rates were observed through Month 30, and nephrocalcinosis grade improvements were observed through Month 24. Clinical Trial Registration: https://clinicaltrials.gov, identifier NCT03905694.

Functional Characterization of Anti-C3bBb Autoantibodies and C3 Glomerulopathy Phenotype.

BACKGROUND: C3 nephritic factors, i.e. autoantibodies that stabilize the C3 convertase of the alternative pathway are the most frequent acquired abnormality in C3 glomerulopathy and primary immunoglobulin-mediated membranoproliferative GN (Ig-MPGN). METHODS: Our study included 27 patients with C3 glomerulopathy (n=21) or Ig-MPGN (n=6), of whom 78% were children at disease onset. At the time of sampling, 13/19 (68%) patients with low C3 levels and 8/8 (100%) patients with normal C3 levels were positive for C3 nephritic factors by haemolytic assay. Using novel Luminex assays, we performed a screening for IgG that recognize and affect the formation and/or the stabilization of the alternative pathway C3 convertase (C3bBb). RESULTS: Using Luminex assays, an increase in C3bBb formation and/or stabilization was observed in the presence of IgG from 18/27 patients, including 9 with a double-function, 6 only enhancing the C3bBb formation, and 3 that exclusively stabilized C3bBb. All patients presenting a formation and stabilization function had a low C3 level, versus 55% without this double-function. The level of C3bBb formation correlated to the plasmatic C3 but not sC5b-9 levels. The stabilization of C3bBb did not correlate with C3 or sC5b-9 levels. At the last follow-up, 5/27 patients (19%) reached kidney failure after a median delay of 87 [52,119] months. The patients positive for double-function anti-C3bBb antibodies had a 5-year kidney survival of 70% compared to 100% in those negative (P=0.02). CONCLUSIONS: Our findings highlight the association of the dual function of C3bBb formation and stabilization with severe C3 consumption and poor kidney survival in C3 glomerulopathy and Ig-MPGN.

Kidney transplantation in children and adolescents with C3 glomerulopathy or immune complex membranoproliferative glomerulonephritis: a real-world study within the CERTAIN research network.

BACKGROUND: Complement 3 glomerulopathy (C3G) and immune complex membranoproliferative glomerulonephritis (IC-MPGN) are ultra-rare chronic kidney diseases with an overall poor prognosis, with approximately 40-50% of patients progressing to kidney failure within 10 years of diagnosis. C3G is characterized by a high rate of disease recurrence in the transplanted kidney. However, there is a lack of published data on clinical outcomes in the pediatric population following transplantation. METHODS: In this multicenter longitudinal cohort study of the Cooperative European Paediatric Renal Transplant Initiative (CERTAIN) registry, we compared the post-transplant outcomes of pediatric patients with C3G (n = 17) or IC-MPGN (n = 3) with a matched case-control group (n = 20). RESULTS: Eleven of 20 children (55%) with C3G or IC-MPGN experienced a recurrence within 5 years post-transplant. Patients with C3G or IC-MPGN had a 5-year graft survival of 61.4%, which was significantly (P = 0.029) lower than the 5-year graft survival of 90% in controls; five patients with C3G or IC-MPGN lost their graft due to recurrence during this observation period. Both the 1-year (20%) and the 5-year (42%) rates of biopsy-proven acute rejection episodes were comparable between patients and controls. Complement-targeted therapy with eculizumab, either as prophylaxis or treatment, did not appear to be effective. CONCLUSIONS: These data in pediatric patients with C3G or IC-MPGN show a high risk of post-transplant disease recurrence (55%) and a significantly lower 5-year graft survival compared to matched controls with other primary kidney diseases. These data underscore the need for post-transplant patients for effective and specific therapies that target the underlying disease mechanism.

Unveiling atypical diagnoses: when whole-genome analysis performed for refractory infantile hypomagnesemia reveals primary hyperoxaluria.

BACKGROUND: Genetic testing is increasingly recognized as crucial in inherited nephropathies. Here, we report on an atypical presentation of a complex tubulopathy that led to an unexpected diagnosis of primary hyperoxaluria type 1 (PH1). CASE DIAGNOSIS: At 2 weeks of age, a premature boy with stunted growth was diagnosed with complex tubulopathy associating hyponatremia, hypokalemia, hypomagnesemia, hypophosphatemia, metabolic acidosis, and acute kidney injury. Despite electrolyte replacement, severe hypomagnesemia persisted while massive parallel sequencing of genes involved in hypomagnesemia yielded negative results, including HNF1ß. At 3 years of age, despite satisfactory growth, hypomagnesemia persisted and nephrocalcinosis appeared and progressed rapidly thereafter. Whole-genome analysis then revealed compound heterozygous mutations in the AGXT gene, thus leading to the diagnosis of PH1. CONCLUSION: Given the emergence of new targeted therapies, thorough genetic analysis including whole-genome analysis should be pursued, especially in case of atypical clinical presentation.

Efficacy and Safety of Lumasiran in Patients With Primary Hyperoxaluria Type 1: Results from a Phase III Clinical Trial.

Introduction: Patients with primary hyperoxaluria type 1 (PH1), a genetic disorder associated with hepatic oxalate overproduction, frequently experience recurrent kidney stones and worsening kidney function. Lumasiran is indicated for the treatment of PH1 to lower urinary and plasma oxalate (POx). Methods: ILLUMINATE-A (NCT03681184) is a phase III trial in patients aged ≥6 years with PH1 and estimated glomerular filtration rate (eGFR) ≥30 ml/min per 1.73 m2. A 6-month double-blind placebo-controlled period is followed by an extension period (≤54 months; all patients receive lumasiran). We report interim data through month 36. Results: Of 39 patients enrolled, 24 of 26 (lumasiran/lumasiran group) and 13 of 13 (placebo/lumasiran group) entered and continue in the extension period. At month 36, in the lumasiran/lumasiran group (36 months of lumasiran treatment) and placebo/lumasiran group (30 months of lumasiran treatment), mean 24-hour urinary oxalate (UOx) reductions from baseline were 63% and 58%, respectively; 76% and 92% of patients reached a 24-hour UOx excretion ≤1.5× the upper limit of normal (ULN). eGFR remained stable. Kidney stone event rates decreased from 2.31 (95% confidence interval: 1.88-2.84) per person-year (PY) during the 12 months before consent to 0.60 (0.46-0.77) per PY during lumasiran treatment. Medullary nephrocalcinosis generally remained stable or improved; approximately one-third of patients (both groups) improved to complete resolution. The most common lumasiran-related adverse events (AEs) were mild, transient injection-site reactions. Conclusion: In patients with PH1, longer-term lumasiran treatment led to sustained reduction in UOx excretion, with an acceptable safety profile and encouraging clinical outcomes.See for Video Abstract.

Creatinine-based formulas are not ideal to estimate glomerular filtration rate in selected pediatric patients: data from a tertiary pediatric nephrology center.

BACKGROUND: Evaluating glomerular filtration rate (GFR) remains challenging in pediatrics; new formulas were developed to increase performance of GFR estimation (eGFR). We aimed to evaluate the recently published formulas as applied to another pediatric population. METHODS: A retrospective study was conducted in a cohort of 307 patients with a "kidney risk" (mean age 12.1 ± 4.5 years, sex ratio 1/1) assessed in a tertiary pediatric nephrology center and a mean measured GFR (mGFR) using plasma iohexol clearance of 85.5 ± 25.3 mL/min/1.73 m2; creatinine levels were measured by IDMS-standardized enzymatic method and cystatin C by immunonephelometry. The following eGFRs were calculated: Schwartz2009, Schwartz-Lyon, CKiDU25creat, and EKFC for eGFR using creatinine (eGFR-creat), CKiDU25cys and FAScys for eGFR using cystatin (eGFR-cys) as well as combined SchwartzCreat-Cys, average (CKiDU25creat-CKiDU25cys), and average (EKFC-FAScys) for eGFR using both biomarkers. The performance of the different formulas was evaluated compared to mGFR by absolute bias measurement and accuracy (p10%, p30%). Results are expressed as mean ± SD. RESULTS: Creatinine-based formulas and especially the new CKiDU25 and EKFC overestimate GFR, even in children with normal kidney function. However, the bias is constant with these two formulas whatever the age group or gender, contrary to the previously published formulas. In contrast, cystatin C-based equations and combined formulas showed good performance in all age groups and all medical conditions with an acceptable bias and p30%. CONCLUSIONS: In our pediatric population, the performance of all creatinine-based formulas is inadequate with significant GFR overestimation, mainly in subjects with mGFR > 75 mL/min/1.73 m2. Conversely, cystatin C-based or combined formulas have acceptable performance in patients followed in a tertiary pediatric nephrology unit.

Metabolic Acidosis Is Associated With an Accelerated Decline of Allograft Function in Pediatric Kidney Transplantation.

Introduction: We investigated the relationship between metabolic acidosis over time and allograft outcome in pediatric kidney transplantation (KTx). Methods: This registry study collected data up to 10 years posttransplant. Survival analysis for a composite end point of graft loss or estimated glomerular filtration rate (eGFR) ≤ 30 ml/min per 1.73 m2 or ≥50% decline from eGFR at month 3 posttransplant was performed. The association of serum bicarbonate concentration (HCO3 -) < 22 mmol/l (metabolic acidosis) and HCO3 - < 18 mmol/l (severe metabolic acidosis) with allograft outcome was investigated using stratified Cox models and marginal structural models. Secondary analyses included the identification of risk factors for metabolic acidosis and the relationship between alkali supplementation and allograft outcome. Results: We report on 1911 patients, of whom 347 reached the composite end point. The prevalence of metabolic acidosis over time ranged from 20.4% to 38.9%. In the adjusted Cox models, metabolic acidosis (hazard ratio [HR], 2.00; 95% confidence interval [CI], 1.54-2.60) and severe metabolic acidosis (HR, 2.49; 95% CI, 1.56-3.99) were associated with allograft dysfunction. Marginal structural models showed similar results (HR, 1.75; 95% CI, 1.32-2.31 and HR, 2.09; 95% CI, 1.23-3.55, respectively). Older age was associated with a lower risk of metabolic acidosis (odds ratio [OR] 0.93/yr older; 95% CI, 0.91-0.96) and severe metabolic acidosis (OR, 0.89; 95% CI, 0.84-0.95). Patients with uncontrolled metabolic acidosis had the worst outcome compared to those without metabolic acidosis and without alkali (HR, 3.70; 95% CI, 2.54-5.40). Conclusion: The degree of metabolic acidosis is associated with allograft dysfunction.

Nedosiran Safety and Efficacy in PH1: Interim Analysis of PHYOX3.

Introduction: Primary hyperoxaluria (PH) is a rare genetic disorder of hepatic glyoxylate metabolism. Nedosiran is an RNA interference (RNAi) therapeutic that the US Food and Drug Administration has approved for treatment of PH1. PHYOX3 is a trial evaluating monthly nedosiran in patients with PH. Methods: In this PHYOX3 interim analysis, participants with PH1 who continued from a single-dose nedosiran trial (PHYOX1), with no previous kidney or liver transplantation, dialysis, or evidence of systemic oxalosis were eligible. The safety and efficacy of once-monthly nedosiran was assessed over 30 months. Results: Thirteen participants completed PHYOX1 and continued into PHYOX3. At baseline, the mean (SD) and median (range) age was 24.2 (6.6) years and 23.0 (14-39) years, respectively; 53.8% were female and 61.5% were White. Mean estimated glomerular filtration rate (eGFR) remained stable (62-84.2 mL/min per 1.73 m2) to month 30. Mean 24-hour urinary oxalate (Uox) excretion showed a sustained reduction from baseline of ≥60% at every visit (months 2-30). From month 2, at least 10 of 13 (76.9%) participants achieved normal (<0.46 mmol/24h; upper limit of assay-normal [ULN]) or near-normal (≥0.46 to <0.60 mmol/24h; ≥ULN to <1.3 × ULN) 24-hour Uox excretion. All participants experienced ≥1 adverse event (AE), mostly mild or moderate in severity (primarily, injection site events). Three serious, not treatment-related AEs were reported; there were no deaths or study discontinuations due to AEs. Conclusion: Nedosiran was well-tolerated in patients with PH1, and treatment resulted in a sustained, substantial reduction in Uox excretion for at least 30 months in this long-term study. No safety signals have been identified to date. The PHYOX3 study is ongoing.

Anti-CFH-associated hemolytic uremic syndrome: do we still need plasma exchange?

BACKGROUND: Between 5 and 50% of atypical hemolytic uremic syndrome (aHUS) cases in children are caused by autoantibodies against complement factor H (CFH). Given the acquired autoimmune nature of the disease, plasma exchange (PE) and various immunosuppressive treatments have been used. More recently, eculizumab has been proposed. METHODS: In this multicenter, retrospective study, we report outcomes of 12 children with anti-FH antibody-associated HUS treated with eculizumab associated with various immunosuppressive regimens. RESULTS: Patients were treated with eculizumab for 15.5 [9.5;23.0] months and 3 received PE or IgG adsorption. Three patients received mycophenolate mofetil (MMF) alone, 1 patient received MMF and steroids, 1 patient received MMF and rituximab, 3 patients received MMF/steroids and rituximab, and 4 patients did not receive any immunosuppression. Anti-FH antibody levels significantly decreased but no difference was observed based on the immunosuppressive regimen. Eculizumab was discontinued in 7/10 patients after 11 [7.5;15.5] months and MMF in 6/8 patients after 36 [35;40] months. Anti-FH titers at MMF discontinuation ranged from 257 to 3425 UI/L. None of these patients relapsed and eGFR at last follow-up was above 70 mL/min/1.73 m2 in all patients. CONCLUSIONS: Eculizumab is effective and safe in inducing and maintaining remission in aHUS secondary to anti-FH antibodies and renders reduction of anti-FH titers less urgent. Anti-FH antibody titers decreased in most patients irrespective of the immunosuppressive treatment chosen, so that a strategy consisting of combining eculizumab with MMF monotherapy seems sufficient at least in non-Indian or less severe forms of anti-FH antibody-associated HUS.

Favorable Outcome After Single-kidney Transplantation From Small Donors in Children: A Match-controlled CERTAIN Registry Study.

BACKGROUND: Kidney transplantation (KTx) from small donors is associated with inferior graft survival in registry studies, whereas single-center studies show favorable results. METHODS: We compared 175 pediatric KTx from small donors ≤20 kg (SDKTx) with 170 age-matched recipients from adult donors (ADKTx) from 20 centers within the Cooperative European Paediatric Renal Transplant Initiative registry. Graft survival and estimated glomerular filtration rate (eGFR) were analyzed by Cox regression and mixed models. Detailed data on surgical and medical management were tested for association with graft survival. RESULTS: One-year graft survival was lower after SDKTx compared with ADKTx (90.9% versus 96.5%; odds ratio of graft loss, 2.92; 95% confidence interval [CI], 1.10-7.80; P  = 0.032), but 5-y graft survival was comparable (90.9% versus 92.7%; adjusted hazard ratio of graft loss 1.9; 95% CI, 0.85-4.25; P  = 0.119). SDKTx recipients had an annual eGFR increase of 8.7 ±â€…6.2 mL/min/1.73 m² compared with a decrease of 6.9 ±â€…5.7 mL/min/1.73 m² in ADKTx recipients resulting in a superior 5-y eGFR (80.5 ±â€…25.5 in SDKTx versus 65.7 ±â€…23.1 mL/min/1.73 m² in ADKTx; P  = 0.008). At 3 y posttransplant, eGFR after single SDKTx was lower than after en bloc SDKTx (86.6 ±â€…20.4 versus 104.6 ±â€…35.9; P  = 0.043) but superior to ADKTx (68.1 ±â€…23.9 mL/min/1.73 m²). Single-kidney SDKTx recipients had a lower rate of hypertension at 3 y than ADKTx recipients (40.0% versus 64.7%; P  = 0.008). CONCLUSIONS: Compared with ADKTx, 5-y graft function is superior in SDKTx and graft survival is similar, even when performed as single KTx. Utilizing small donor organs, preferably as single kidneys in experienced centers, is a viable option to increase the donor pool for pediatric recipients.

Nephrocalcinosis can disappear in infants receiving early lumasiran therapy.

BACKGROUND: Lumasiran is the first RNA interference (RNAi) therapy of primary hyperoxaluria type 1 (PH1). Here, we report on the rapid improvement and even disappearance of nephrocalcinosis after early lumasiran therapy. CASE-DIAGNOSIS/TREATMENT: In patient 1, PH1 was suspected due to incidental discovery of nephrocalcinosis stage 3 in a 4-month-old boy. Bilateral nephrocalcinosis stage 3 was diagnosed in patient 2 at 22 months concomitantly to acute pyelonephritis. Urinary oxalate (UOx) and glycolate (UGly) were increased in both patients allowing to start lumasiran therapy before genetic confirmation. Nephrocalcinosis started to improve and disappeared after 27 months and 1 year of treatment in patients 1 and 2, respectively. CONCLUSION: These cases illustrate the efficacy of early lumasiran therapy in infants to improve and even normalize nephrocalcinosis. As proposed in the 2023 European guidelines, the interest of starting treatment quickly without waiting for genetic confirmation may have an impact on long-term outcomes.

Is shrunken pore syndrome also a reality in children?

BACKGROUND: Shrunken pore syndrome (SPS) is defined as cystatin C-based-eGFR (eGFRcys)/creatinine-based-eGFR (eGFRcreat) <0.6 or 0.7 and is associated with an increased cardiovascular risk. SPS has been described in children, but no link to increased morbi-mortality was demonstrated. OBJECTIVES: Study the prevalence of SPS in a pediatric population using several glomerular filtration rate (GFR) estimating formulas and measured GFR and evaluate the potential link with cardiovascular risk. METHODS: In 307 renal risk pediatric patients, we studied prevalence of SPS either with CKiDU25creat and cyst or with FAScreat and cyst and EKFCcreat. The characteristics of patients with SPS (defined with Full-age spectrum equation (FAS) and/or European Kidney Function Consortium equation (EKFC)) were compared. RESULTS AND CONCLUSION: The prevalence of SPS varies widely depending on the threshold and the formulas used. Higher C-reactive protein (CRP) and phosphate levels and smaller size are observed in children with SPS defined with FAS and/or EKFC and might be associated with long-term increased cardiovascular risk. Further studies in wider general pediatric populations are warranted.

Integrated clinical pharmacy activities into the pediatric kidney graft pathway / Activités de pharmacie clinique intégrées dans le parcours du patient de greffe rénale pédiatrique

The pediatric renal graft pathway is at risk of care discontinuation, even though therapeutic adherence is essential. The objective is to evaluate the integration of clinical pharmacy activities into this care pathway. This feasibility study is divided into three stages: structuring, implementing and evaluation. In pre-transplant, immediate and remote post-transplant, interviews were proposed as well as the pharmaceutical analysis of medication prescriptions. In 8 months duration, 32 patients were included. All patients included in pre-transplant and immediate post-transplant benefited from the activities. At M0, all the prescriptions analyzed resulted in at least one problem detected. Half of the transplanted patients benefited from M1 maintenance, one patient from M3 maintenance and no M6 follow-up could be carried out. This work concludes with the good feasibility and integration of clinical pharmacy activities within the care pathway.

Le parcours de greffe rénale pédiatrique est à risque de rupture de soins car les patients sont polymédiqués alors même que l'adhésion thérapeutique est essentielle. L'objectif est d'évaluer l'intégration d'activités de pharmacie clinique dans ce parcours de soins. Cette étude de faisabilité se décline en trois étapes : structuration, mise en œuvre et évaluation. En pré-greffe, post-greffe immédiate et post-greffe à distance, des entretiens ont été proposés ainsi que l'analyse pharmaceutique des prescriptions médicamenteuses. En huit mois, 32 patients ont été inclus. Tous les patients inclus en pré-greffe et en post-greffe immédiate ont bénéficié des activités. À M0, toutes les prescriptions analysées ont abouti à au moins un problème détecté. La moitié des patients greffés ont bénéficié de l'entretien à M1, un patient de l'entretien à M3 et aucun suivi à M6 n'a pu être réalisé. Ce travail conclut à la bonne faisabilité et intégration des activités de pharmacie clinique au sein du parcours de soins.

Validation of a prediction system for risk of kidney allograft failure in pediatric kidney transplant recipients: An international observational study.

Predicting long-term kidney allograft failure is an unmet need for clinical care and clinical trial optimization in children. We aimed to validate a kidney allograft failure risk prediction system in a large international cohort of pediatric kidney transplant recipients. Patients from 20 centers in Europe and the United States, transplanted between 2004 and 2017, were included. Allograft assessment included estimated glomerular filtration rate, urine protein-to-creatinine ratio, circulating antihuman leukocyte antigen donor-specific antibody, and kidney allograft histology. Individual predictions of allograft failure were calculated using the integrative box (iBox) system. Prediction performances were assessed using discrimination and calibration. The allograft evaluations were performed in 706 kidney transplant recipients at a median time of 9.1 (interquartile range, 3.3-19.2) months posttransplant; mean estimated glomerular filtration rate was 68.7 ± 28.1 mL/min/1.73 m2, and median urine protein-to-creatinine ratio was 0.1 (0.0-0.4) g/g, and 134 (19.0%) patients had antihuman leukocyte antigen donor-specific antibodies. The iBox exhibited accurate calibration and discrimination for predicting the outcomes up to 10 years after evaluation, with a C-index of 0.81 (95% confidence interval, 0.75-0.87). This study confirms the generalizability of the iBox to predict long-term kidney allograft failure in children, with performances similar to those reported in adults. These results support the use of the iBox to improve patient monitoring and facilitate clinical trials in children.

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 ).

Lumasiran for Advanced Primary Hyperoxaluria Type 1: Phase 3 ILLUMINATE-C Trial.

RATIONALE & OBJECTIVE: Lumasiran reduces urinary and plasma oxalate (POx) in patients with primary hyperoxaluria type 1 (PH1) and relatively preserved kidney function. ILLUMINATE-C evaluates the efficacy, safety, pharmacokinetics, and pharmacodynamics of lumasiran in patients with PH1 and advanced kidney disease. STUDY DESIGN: Phase 3, open-label, single-arm trial. SETTING & PARTICIPANTS: Multinational study; enrolled patients with PH1 of all ages, estimated glomerular filtration rate ≤45 mL/min/1.73 m2 (if age ≥12 months) or increased serum creatinine level (if age <12 months), and POx ≥20 µmol/L at screening, including patients with or without systemic oxalosis. INTERVENTION: Lumasiran administered subcutaneously; 3 monthly doses followed by monthly or quarterly weight-based dosing. OUTCOME: Primary end point: percent change in POx from baseline to month 6 (cohort A; not receiving hemodialysis at enrollment) and percent change in predialysis POx from baseline to month 6 (cohort B; receiving hemodialysis at enrollment). Pharmacodynamic secondary end points: percent change in POx area under the curve between dialysis sessions (cohort B only); absolute change in POx; percent and absolute change in spot urinary oxalate-creatinine ratio; and 24-hour urinary oxalate adjusted for body surface area. RESULTS: All patients (N = 21; 43% female; 76% White) completed the 6-month primary analysis period. Median age at consent was 8 (range, 0-59) years. For the primary end point, least-squares mean reductions in POx were 33.3% (95% CI, -15.2% to 81.8%) in cohort A (n = 6) and 42.4% (95% CI, 34.2%-50.7%) in cohort B (n = 15). Improvements were also observed in all pharmacodynamic secondary end points. Most adverse events were mild or moderate. No patient discontinued treatment or withdrew from the study. The most commonly reported lumasiran-related adverse events were injection-site reactions, all of which were mild and transient. LIMITATIONS: Single-arm study without placebo control. CONCLUSIONS: Lumasiran resulted in substantial reductions in POx with acceptable safety in patients with PH1 who have advanced kidney disease, supporting its efficacy and safety in this patient population. FUNDING: Alnylam Pharmaceuticals. TRIAL REGISTRATION: Registered at ClinicalTrials.gov with study number NCT04152200 and at EudraCT with study number 2019-001346-17. PLAIN-LANGUAGE SUMMARY: Primary hyperoxaluria type 1 (PH1) is a rare genetic disease characterized by excessive hepatic oxalate production that frequently causes kidney failure. Lumasiran is an RNA interference therapeutic that is administered subcutaneously for the treatment of PH1. Lumasiran has been shown to reduce oxalate levels in the urine and plasma of patients with PH1 who have relatively preserved kidney function. In the ILLUMINATE-C study, the efficacy and safety of lumasiran were evaluated in patients with PH1 and advanced kidney disease, including a cohort of patients undergoing hemodialysis. During the 6-month primary analysis period, lumasiran resulted in substantial reductions in plasma oxalate with acceptable safety in patients with PH1 complicated by advanced kidney disease.

Efficacy and safety of lumasiran for infants and young children with primary hyperoxaluria type 1: 12-month analysis of the phase 3 ILLUMINATE-B trial.

BACKGROUND: Primary hyperoxaluria type 1 (PH1) is a rare genetic disease that causes progressive kidney damage and systemic oxalosis due to hepatic overproduction of oxalate. Lumasiran demonstrated efficacy and safety in the 6-month primary analysis period of the phase 3, multinational, open-label, single-arm ILLUMINATE-B study of infants and children < 6 years old with PH1 (ClinicalTrials.gov: NCT03905694 (4/1/2019); EudraCT: 2018-004,014-17 (10/12/2018)). Outcomes in the ILLUMINATE-B extension period (EP) for patients who completed ≥ 12 months on study are reported here. METHODS: Of the 18 patients enrolled in the 6-month primary analysis period, all entered the EP and completed ≥ 6 additional months of lumasiran treatment (median (range) duration of total exposure, 17.8 (12.7-20.5) months). RESULTS: Lumasiran treatment was previously reported to reduce spot urinary oxalate:creatinine ratio by 72% at month 6, which was maintained at 72% at month 12; mean month 12 reductions in prespecified weight subgroups were 89%, 68%, and 71% for patients weighing < 10 kg, 10 to < 20 kg, and ≥ 20 kg, respectively. The mean reduction from baseline in plasma oxalate level was reported to be 32% at month 6, and this improved to 47% at month 12. Additional improvements were also seen in nephrocalcinosis grade, and kidney stone event rates remained low. The most common lumasiran-related adverse events were mild, transient injection-site reactions (3 patients (17%)). CONCLUSIONS: Lumasiran treatment provided sustained reductions in urinary and plasma oxalate through month 12 across all weight subgroups, with an acceptable safety profile, in infants and young children with PH1. A higher resolution version of the Graphical abstract is available as Supplementary information.

Idiopathic nephrotic syndrome relapse following COVID-19 vaccination: a series of 25 cases.

Background: Several cases of idiopathic nephrotic syndrome (INS) relapse following the administration of coronavirus disease 2019 (COVID-19) vaccines have recently been reported, raising questions about the potential relationship between the immune response to COVID-19 vaccination and INS pathogenesis. Methods: We performed a retrospective multicentre survey describing the clinical and biological characteristics of patients presenting a relapse of INS after COVID-19 vaccination, with an assessment of outcome under treatment. Results: We identified 25 patients (16 men and 9 women) presenting a relapse within 1 month of a COVID-19 vaccine injection. The glomerular disease was of childhood onset in half of the patients and most patients (21/25) had received at least one immunosuppressive drug in addition to steroids for frequently relapsing or steroid-dependent nephrotic syndrome (NS). All patients were in a stable condition at the time of injection and 11 had no specific treatment. In five patients, the last relapse was reported >5 years before vaccine injection. The Pfizer-BioNTech (BNT162b2) vaccine was used in 80% of the patients. In 18 cases, INS relapse occurred after the first injection, a mean of 17.5 days after vaccination. A second injection was nevertheless administered in 14 of these patients. Five relapses occurred after administration of the second dose and two relapses after the administration of the third dose. All but one of the patients received steroids as first-line treatment, with an additional immunosuppressive agent in nine cases. During follow-up, complete remission was achieved in 21 patients, within 1 month in 17 cases. Only one patient had not achieved at least partial remission after 3 months of follow-up. Conclusions: This case series suggests that, in rare patients, COVID-19 vaccination may trigger INS relapse that is generally easy to control. These findings should encourage physicians to persuade their patients to complete the COVID-19 vaccination schedule.