Event-free survival of maralixibat-treated patients with Alagille syndrome compared to a real-world cohort from GALA.

BACKGROUND AND AIMS: Alagille syndrome (ALGS) is characterized by chronic cholestasis with associated pruritus and extrahepatic anomalies. Maralixibat, an ileal bile acid transporter inhibitor, is an approved pharmacologic therapy for cholestatic pruritus in ALGS. Since long-term placebo-controlled studies are not feasible or ethical in children with rare diseases, a novel approach was taken comparing 6-year outcomes from maralixibat trials with an aligned and harmonized natural history cohort from the G lobal AL agille A lliance (GALA) study. APPROACH AND RESULTS: Maralixibat trials comprise 84 patients with ALGS with up to 6 years of treatment. GALA contains retrospective data from 1438 participants. GALA was filtered to align with key maralixibat eligibility criteria, yielding 469 participants. Serum bile acids could not be included in the GALA filtering criteria as these are not routinely performed in clinical practice. Index time was determined through maximum likelihood estimation in an effort to align the disease severity between the two cohorts with the initiation of maralixibat. Event-free survival, defined as the time to first event of manifestations of portal hypertension (variceal bleeding, ascites requiring therapy), surgical biliary diversion, liver transplant, or death, was analyzed by Cox proportional hazards methods. Sensitivity analyses and adjustments for covariates were applied. Age, total bilirubin, gamma-glutamyl transferase, and alanine aminotransferase were balanced between groups with no statistical differences. Event-free survival in the maralixibat cohort was significantly better than the GALA cohort (HR, 0.305; 95% CI, 0.189-0.491; p <0.0001). Multiple sensitivity and subgroup analyses (including serum bile acid availability) showed similar findings. CONCLUSIONS: This study demonstrates a novel application of a robust statistical method to evaluate outcomes in long-term intervention studies where placebo comparisons are not feasible, providing wide application for rare diseases. This comparison with real-world natural history data suggests that maralixibat improves event-free survival in patients with ALGS.

Natural history of liver disease in a large international cohort of children with Alagille syndrome: Results from the GALA study.

BACKGROUND AND AIMS: Alagille syndrome (ALGS) is a multisystem disorder, characterized by cholestasis. Existing outcome data are largely derived from tertiary centers, and real-world data are lacking. This study aimed to elucidate the natural history of liver disease in a contemporary, international cohort of children with ALGS. APPROACH AND RESULTS: This was a multicenter retrospective study of children with a clinically and/or genetically confirmed ALGS diagnosis, born between January 1997 and August 2019. Native liver survival (NLS) and event-free survival rates were assessed. Cox models were constructed to identify early biochemical predictors of clinically evident portal hypertension (CEPH) and NLS. In total, 1433 children (57% male) from 67 centers in 29 countries were included. The 10 and 18-year NLS rates were 54.4% and 40.3%. By 10 and 18 years, 51.5% and 66.0% of children with ALGS experienced ≥1 adverse liver-related event (CEPH, transplant, or death). Children (>6 and ≤12 months) with median total bilirubin (TB) levels between ≥5.0 and <10.0 mg/dl had a 4.1-fold (95% confidence interval [CI], 1.6-10.8), and those ≥10.0 mg/dl had an 8.0-fold (95% CI, 3.4-18.4) increased risk of developing CEPH compared with those <5.0 mg/dl. Median TB levels between ≥5.0 and <10.0 mg/dl and >10.0 mg/dl were associated with a 4.8 (95% CI, 2.4-9.7) and 15.6 (95% CI, 8.7-28.2) increased risk of transplantation relative to <5.0 mg/dl. Median TB <5.0 mg/dl were associated with higher NLS rates relative to ≥5.0 mg/dl, with 79% reaching adulthood with native liver ( p < 0.001). CONCLUSIONS: In this large international cohort of ALGS, only 40.3% of children reach adulthood with their native liver. A TB <5.0 mg/dl between 6 and 12 months of age is associated with better hepatic outcomes. These thresholds provide clinicians with an objective tool to assist with clinical decision-making and in the evaluation of therapies.

Maralixibat for the treatment of PFIC: Long-term, IBAT inhibition in an open-label, Phase 2 study.

Children with progressive familial intrahepatic cholestasis, including bile salt export pump (BSEP) and familial intrahepatic cholestasis-associated protein 1 (FIC1) deficiencies, suffer debilitating cholestatic pruritus that adversely affects growth and quality of life (QoL). Reliance on surgical interventions, including liver transplantation, highlights the unmet therapeutic need. INDIGO was an open-label, Phase 2, international, long-term study to assess the efficacy and safety of maralixibat in children with FIC1 or BSEP deficiencies. Thirty-three patients, ranging from 12 months to 18 years of age, were enrolled. Eight had FIC1 deficiency and 25 had BSEP deficiency. Of the latter, 6 had biallelic, protein truncating mutations (t)-BSEP, and 19 had ≥ 1 nontruncating mutation (nt)-BSEP. Patients received maralixibat 266 µg/kg orally, once daily, from baseline to Week 72, with twice-daily dosing permitted from Week 72. Long-term efficacy was determined at Week 240. Serum bile acid (sBA) response (reduction in sBAs of > 75% from baseline or concentrations <102.0 µmol/L) was achieved in 7 patients with nt-BSEP, 6 during once-daily dosing, and 1 after switching to twice-daily dosing. sBA responders also demonstrated marked reductions in sBAs and pruritus, and increases in height, weight, and QoL. All sBA responders remained liver transplant-free after > 5 years. No patients with FIC1 deficiency or t-BSEP deficiency met the sBA responder criteria during the study. Maralixibat was generally well-tolerated throughout the study. Conclusion: Response to maralixibat was dependent on progressive familial intrahepatic cholestasis subtype, and 6 of 19 patients with nt-BSEP experienced rapid and sustained reductions in sBA levels. The 7 responders survived with native liver and experienced clinically significant reductions in pruritus and meaningful improvements in growth and QoL. Maralixibat may represent a well-tolerated alternative to surgical intervention.

Evolution of Acute Kidney Injury and Its Association With Systemic Hemodynamics in Children With Fluid-Refractory Septic Shock.

OBJECTIVES: There are no studies in pediatrics evaluating the progression of acute kidney injury in septic shock. We investigated the evolution of sepsis-associated acute kidney injury and its association with systemic hemodynamics in children with fluid-refractory septic shock. DESIGN: Prospective cohort study. SETTING: PICU of a tertiary care hospital. PATIENTS: All patients with fluid-refractory septic shock (n = 61) between September 2010 and February 2014. INTERVENTIONS: Hemodynamic variables using noninvasive ultrasound cardiac output monitor were measured at admission and 6 hourly thereafter till 48 hours. We used the Kidney Disease: Improving Global Outcomes criteria to define and stage acute kidney injury. Associations between various hemodynamic variables and development of acute kidney injury were evaluated. Severe acute kidney injury was defined as stage 2 or 3 acute kidney injury and was compared with no acute kidney injury or stage 1 acute kidney injury. MEASUREMENTS AND MAIN RESULTS: Severe acute kidney injury developed in 29.5% (n = 18) of the 61 children with fluid-refractory septic shock, whereas 43 patients (70.49%) had either no or stage 1 acute kidney injury. Most patients who developed acute kidney injury did so within the first 48 hours of PICU admission. Severe acute kidney injury conferred a three-fold increased risk of death by day 28 (hazard ratio, 3.23; 95% CI, 1.52-6.67; p = 0.002), longer ICU stay, and increased duration of mechanical ventilation. Central venous pressure at presentation was higher in severe acute kidney injury by 5 cm H2O. Highest lactate in the first 24 hours of PICU admission, low diastolic blood pressure, low systemic vascular resistance index at admission were associated with severe acute kidney injury. This model reliably predicted stage 2/3 acute kidney injury by day 3 with area under the curve equals to 94%; 95% CI, 88.3-99.99. None of the other hemodynamic variables showed any association with severe acute kidney injury. CONCLUSIONS: Manifestations of sepsis-associated acute kidney injury often occur early after PICU admission and is associated with increased morbidity and mortality. There is a need to develop a predictive model in septic shock which could facilitate early detection of acute kidney injury.

King's Variceal Prediction Score: A Novel Noninvasive Marker of Portal Hypertension in Pediatric Chronic Liver Disease.

BACKGROUND AND AIMS: Variceal haemorrhage can be a life-threatening complication of chronic liver disease in children. There is limited evidence about the optimal prophylactic management and selection criteria of children who will benefit from upper gastrointestinal endoscopy. METHODS: Children presenting in our centre with suspected portal hypertension or gastrointestinal bleeding and undergoing their first oesophagogastroduodenoscopy between 2005 and 2012 were included. Clinical, biochemical, and radiological data were collected. A separate validation cohort from May 2013 to October 2014 was obtained. RESULTS: Data on 124 treatment-naïve patients were collected; 50% had biliary atresia. Thirty-five (28%) children presented with gastrointestinal bleeding and overall 79 (64%) had clinically significant (grade II-III) varices. Clinical prediction rule, aspartate aminotransferase-platelet ratio index, and varices prediction rule had at optimal cut-off sensitivity and specificity of 76% and 59%, 60% and 55%, and 80% and 59%, respectively. Logistic regression yielded a new prediction rule of (3 × albumin ([g/dL]) -  (2 - equivalent adult spleen size [cm]). This King's variceal prediction score had a favourable areas under the curve of 0.772 (0.677-0.867) compared to clinical prediction rule 0.732 (0.632-0.832). At the optimal cut-off of 76 this yielded a sensitivity and specificity of 72% and 73% and a positive and negative predictive value of 82% and 60%, respectively. In the validation cohort areas under the curve was 0.818 (0.654-0.995) with sensitivity and specificity of 78% and 73%, respectively. CONCLUSIONS: Our new prediction score may be a useful tool in the selection of children with clinically significant varices eligible for a screening endoscopy.