Giroctocogene fitelparvovec gene therapy for severe hemophilia A: 104-week analysis of the phase 1/2 Alta study.

ABSTRACT: Patients with hemophilia A require exogenous factor VIII (FVIII) or nonfactor hemostatic agents to prevent spontaneous bleeding events. Adeno-associated virus (AAV) vector-based gene therapy is under clinical investigation to enable endogenous FVIII production. Giroctocogene fitelparvovec is a recombinant AAV serotype 6 vector containing the coding sequence for the B-domain-deleted human F8 gene. In the ongoing phase 1/2, dose-ranging Alta study, 4 sequential cohorts of male participants with severe hemophilia A received a single IV dose of giroctocogene fitelparvovec. The primary end points are safety and changes in circulating FVIII activity. Interim results up to 214 weeks after treatment for all participants are presented. Eleven participants were dosed. Increases in alanine and aspartate aminotransferases were the most common treatment-related adverse events (AEs), which resolved with corticosteroid administration. Two treatment-related serious AEs (hypotension and pyrexia) were reported in 1 participant within 6 hours of infusion and resolved within 24 hours after infusion. At the highest dose level (3 × 1013 vg/kg; n = 5), the mean circulating FVIII activity level at week 52 was 42.6% (range, 7.8%-122.3%), and at week 104 it was 25.4% (range, 0.9%-71.6%) based on a chromogenic assay. No liver masses, thrombotic events, or confirmed inhibitors were detected in any participant. These interim 104-week data suggest that giroctocogene fitelparvovec is generally well tolerated with appropriate clinical management and has the potential to provide clinically meaningful FVIII activity levels, as indicated by the low rate of bleeding events in the highest dose cohort. This trial was registered at www.clinicaltrials.gov as #NCT03061201.

Belatacept-based regimens versus a cyclosporine A-based regimen in kidney transplant recipients: 2-year results from the BENEFIT and BENEFIT-EXT studies.

BACKGROUND: At 1 year, belatacept was associated with similar patient/graft survival, better renal function, and an improved cardiovascular/metabolic risk profile versus cyclosporine A (CsA) in the Belatacept Evaluation of Nephroprotection and Efficacy as Firstline Immunosuppression Trial (BENEFIT) and Belatacept Evaluation of Nephroprotection and Efficacy as Firstline Immunosuppression Trial-EXTended criteria donors (BENEFIT-EXT) studies. Acute rejection was more frequent with belatacept in BENEFIT. Posttransplant lymphoproliferative disorder (PTLD)--specifically central nervous system PTLD--was observed more frequently in belatacept-treated patients. This analysis assesses outcomes from BENEFIT and BENEFIT-EXT after 2 years of treatment. METHODS: Patients received a more intensive (MI) or a less intensive (LI) regimen of belatacept or a CsA-based regimen. RESULTS: Four hundred ninety-three of 666 patients (74%) in BENEFIT and 347 of 543 (64%) in BENEFIT-EXT completed 2 years of treatment. The proportion of patients who survived with a functioning graft was similar across groups (BENEFIT: 94% MI, 95% LI, and 91% CsA; BENEFIT-EXT: 83% MI, 84% LI, and 83% CsA). Belatacept's renal benefits were sustained, as evidenced by a 16 to 17 mL/min (BENEFIT) and an 8 to 10 mL/min (BENEFIT-EXT) higher calculated glomerular filtration rate in the belatacept groups versus CsA. There were few new acute rejection episodes in either study between years 1 and 2. Because PTLD risk was highest in Epstein-Barr virus (EBV) (-) patients, an efficacy analysis of EBV (+) patients was performed and was consistent with the overall population results. There were two previously reported cases of PTLD in each study between years 1 and 2 in the belatacept groups. The overall balance of safety and efficacy favored the LI over the MI regimen. CONCLUSIONS: At 2 years, belatacept-based regimens sustained better renal function, similar patient/graft survival, and an improved cardiovascular/metabolic risk profile versus CsA; outcomes that were maintained in EBV (+) patients. No new safety signals emerged.

Single ventricle palliation: greater risk of complications with the Fontan procedure than with the bidirectional Glenn procedure alone.

BACKGROUND: This study was performed to evaluate and compare the early, intermediate, and long-term outcomes of the bidirectional Glenn procedure and Fontan procedure in patients who live at moderately high altitude. METHODS: The outcome of each method of palliation for patients with a functionally single ventricle was retrospectively evaluated from a review of medical records. RESULTS: The bidirectional Glenn procedure was performed in 177 patients from October 1984 to June 2004. The Fontan procedure was performed in 149 patients from June 1978 to June 2004. Cardiovascular death or heart transplantation occurred in 8% of patients after the bidirectional Glenn procedure and 17% of patients after the Fontan procedure. Complications of systemic thromboembolic events, bleeding associated with anticoagulation therapy, protein losing enteropathy, and arrhythmias requiring implantation of a pacemaker, cardioversion, or radiofrequency ablation occurred in 7% of patients after the bidirectional Glenn procedure and 47% of patients after the Fontan procedure. Cardiovascular deaths and heart transplantation occurred less frequently when the Fontan procedure was performed in patients with a previous bidirectional Glenn procedure. However, the actuarial transplant-free survival and freedom from complications was not superior for a subgroup of patients who had a Fontan procedure after a bidirectional Glenn procedure in comparison to a subgroup of patients who had a bidirectional Glenn procedure alone. CONCLUSIONS: The bidirectional Glenn procedure can be used for long-term palliation of patients with a functionally single ventricle. Additional palliation with a Fontan procedure may increase the risk of stroke, protein losing enteropathy and arrhythmias without improving survival.

Extracorporeal membrane oxygenation for cardiac disease: no longer a mistaken diagnosis.

Extracorporeal membrane oxygenation (ECMO) has become a valuable adjunct in caring for infants and children with heart disease. Since the initial reports of ECMO support for cardiac failure in children, the number of centers providing cardiac support and the number of cases of cardiac ECMO have steadily increased. The International Registry for Extracorporeal Life Support Organization has reported survival statistics for cardiac cases in neonates, children, and adults ranging from 33% to 43%. These numbers are similar to the survival from recent reports by Morris (39%) and Chaturvedi (49%). Survival is influenced by ability to be weaned from bypass in the operating room and by residual structural disease and multi-organ system failure but not by cardiac arrest and single ventricle physiology. To improve results in the future, we need to focus on better predicting the need for support and avoiding multi-organ system failure before initiating ECMO. Rapid deployment of ECMO may further improve results for patients who deteriorate suddenly in the intensive care unit.

Current status of surgery for rheumatic carditis in children.

BACKGROUND: The incidence of rheumatic heart disease (RHD) has increased recently in the western United States. We reviewed our 18-year surgical experience with RHD in children to examine current surgical techniques and results. METHODS: From 1985 until 2003, 596 children (<21 years) with rheumatic fever were seen at Primary Children's Medical Center. Rheumatic carditis was diagnosed in 366 patients (61.4%). Twenty-six with carditis (26/366, 7.1%) required operation for rheumatic valve disease including 8 for mitral regurgitation, 7 for mitral and aortic regurgitation, 4 for aortic regurgitation, 4 for mitral regurgitation and stenosis, 2 for combined mitral stenosis and regurgitation with aortic insufficiency, and 1 for mitral and tricuspid regurgitation. RESULTS: Mean age at operation was 13.5 +/- 4 years. Three patients required operation during the acute phase of rheumatic fever (< 6 weeks), 2 during the subacute phase (< 6 months), and 21 during the chronic phase after the episode of rheumatic fever (6.7 +/- 3 years). Mitral valve repair was possible in 19 of 22 patients who required mitral operation. Aortic valve repair was possible in 4 patients whereas replacement was necessary in 9, including 2 Ross procedures. No operative deaths were recorded and 2 late deaths occurred at 4.6 and 10 years. Actuarial survival was 94% at 5 years and 78% at 10 years. Six patients required reoperation; actuarial freedom from reoperation was 78% at 5 years, 65% at 10 years, and 49% at 15 years. All survivors are in New York Heart Association class I or II. CONCLUSIONS: Children with RHD in the United States uncommonly require valve operation. Mitral repair with a technique that allows annular growth is possible in most children with good long-term functional results. Long-term surveillance of children with RHD is necessary because of the possible need for late valve operation.

Immunogenicity of decellularized cryopreserved allografts in pediatric cardiac surgery: comparison with standard cryopreserved allografts.

BACKGROUND: Recognition of the immunogenicity of standard cryopreserved allografts has led to the development of new decellularized allografts (CryoValve SG; CryoLife, Inc, Kennesaw, Ga). This preliminary study examined the HLA antibody response to these decellularized allografts and compared it with the response to standard allograft material. METHODS: We prospectively measured the frequency of panel-reactive HLA class I (HLA-A, HLA-B, and HLA-C) and class II (HLA-DR/DQ) alloantibodies in 14 children (age 8.5 +/- 7.9 years) receiving decellularized, cryopreserved allografts, including 6 undergoing allograft patch insertion and 8 with a valved pulmonary allograft. We compared them with 20 historical control subjects (age 1.7 +/- 2.4 years) undergoing implantation of standard cryopreserved allografts, 8 with valves and 12 with allograft patch. All patients had panel-reactive antibody levels measured before and at 1, 3, and 12 months after the operation. HLA class I and class II panel-reactive antibody levels were determined with a sensitive flow cytometry technique. RESULTS: We found panel-reactive antibody levels in decellularized allografts to be elevated slightly from preoperative levels for both class I and class II antibodies at 1, 3, and 12 months (P >.05). The panel-reactive antibody level for both class I and class II antibodies were significantly lower for decellularized allografts as compared to standard allografts. Functionally, the allografts were similar with decellularized valved grafts showing a peak echo-determined systolic gradient of 13 +/- 15 mm Hg at 8 +/- 2.6 months postoperatively as compared to a gradient of 24 +/- 18 mm Hg measured 12 +/- 6 months postoperatively in standard allografts (P =.11). CONCLUSIONS: Decellularized grafts elicited significantly lower levels of class I and class II HLA antibody formation at 1, 3, and 12 months after implantation than did standard cryopreserved allografts. Early hemodynamic function of decellularized grafts was similar to that of standard cryopreserved allograft valves. Further experience is necessary to determine whether the reduced immunogenicity of decellularized allografts will truly allow tissue ingrowth and improved long-term durability in patients.

Ebstein's anomaly: Indications for repair and surgical technique.

Ebstein's anomaly of the tricuspid valve is characterized by a regurgitant tricuspid valve with a large anterior leaflet and septal and tricuspid leaflets displaced into the right ventricle. Associated anomalies are common, especially atrial septal communication and right ventricular outflow tract obstruction. Clinical presentation includes a spectrum from minimal hemodynamic derangement and mild exercise intolerance to severe cardiopulmonary abnormalities and grave illness. The natural history of the disease is extremely variable; the worst prognosis is in the youngest patients, who often have associated cardiac abnormalities. Operative procedures range from ligation of a patent ductus arteriosus to cardiac transplantation. Tricuspid valvuloplasty has been advanced by several investigators and can be considered in nearly all cases. Repairs are based on the creation of a monocuspid or bicuspid valve with reduction of the enlarged annulus. While tricuspid valve repair or replacement is indicated for symptomatic children and adults, the management of the symptomatic neonate is difficult. Patients are stratified according to clinical status and morphology, then treated with observation, valve repair, conversion to single ventricle, or transplantation. We review the anatomy and pathophysiology of Ebstein's anomaly, the indications for surgery, and the appropriate timing of surgical intervention. Current techniques of tricuspid valvuloplasty are described and unresolved issues are discussed, including the role for superior cavopulmonary anastomosis, the management of symptomatic infants, and the necessity of ventricular plication in valve repair. Copyright 1999 by W.B. Saunders Company