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.

MicroRNA-34a-5p as a promising early circulating preclinical biomarker of doxorubicin-induced chronic cardiotoxicity.

Cardiotoxicity is a serious adverse effect of an anticancer drug, doxorubicin (DOX), which can occur within a year or decades after completion of therapy. The present study was designed to address a knowledge gap concerning a lack of circulating biomarkers capable of predicting the risk of cardiotoxicity induced by DOX. Profiling of 2083 microRNAs (miRNAs) in mouse plasma revealed 81 differentially expressed miRNAs 1 week after 6, 9, 12, 18, or 24 mg/kg total cumulative DOX doses (early-onset model) or saline (SAL). Among these, the expression of seven miRNAs was altered prior to the onset of myocardial injury at 12 mg/kg and higher cumulative doses. The expression of only miR-34a-5p was significantly (false discovery rate [FDR] < 0.1) elevated at all total cumulative doses compared with concurrent SAL-treated controls and showed a statistically significant dose-related response. The trend in plasma miR-34a-5p expression levels during DOX exposures also correlated with a significant dose-related increase in cardiac expression of miR-34a-5p in these mice. Administration of a cardioprotective drug, dexrazoxane, to mice before DOX treatment, significantly mitigated miR-34a-5p expression in both plasma and heart in conjunction with attenuation of cardiac pathology. This association between plasma and heart may suggest miR-34a-5p as a potential early circulating marker of early-onset DOX cardiotoxicity. In addition, higher expression of miR-34a-5p (FDR < 0.1) in plasma and heart compared with SAL-treated controls 24 weeks after 24 mg/kg total cumulative DOX dose, when cardiac function was altered in our recently established delayed-onset cardiotoxicity model, indicated its potential as an early biomarker of delayed-onset cardiotoxicity.

Doxorubicin-induced delayed-onset subclinical cardiotoxicity in mice.

Subclinical cardiotoxicity at low total cumulative doxorubicin (DOX) doses can manifest into cardiomyopathy in long-term cancer survivors. However, the underlying mechanisms are poorly understood. In male B6C3F1 mice, assessment of cardiac function by echocardiography was performed at 1, 4, 10, 17, and 24 weeks after exposure to 6, 9, 12, and 24 mg/kg total cumulative DOX doses or saline (SAL) to monitor development of delayed-onset cardiotoxicity. The 6- or 9-mg/kg total cumulative doses resulted in a significant time-dependent decline in systolic function (left ventricular ejection fraction (LVEF) and fractional shortening (FS)) during the 24-week recovery although there was not a significant alteration in % LVEF or % FS at any specific time point during the recovery. A significant decline in systolic function was elicited by the cardiotoxic cumulative DOX dose (24 mg/kg) during the 4- to 24-week period after treatment compared to SAL-treated counterparts. At 24 weeks after DOX treatment, a significant dose-related decrease in the expression of genes and proteins involved in sarcoplasmic reticulum (SR) calcium homeostasis (Ryr2 and Serca2) was associated with a dose-related increase in the transcript level of Casp12 (SR-specific apoptosis) in hearts. These mice also showed enhanced apoptotic activity in hearts indicated by a significant dose-related elevation in the number of apoptotic cardiomyocytes compared to SAL-treated counterparts. These findings collectively suggest that a steady decline in SR calcium handling and apoptosis might be involved in the development of subclinical cardiotoxicity that can evolve into irreversible cardiomyopathy later in life.

A Novel Germline TP53 Mutation in a Patient With Li-Fraumeni Syndrome: Resolving a Variant of Uncertain Significance.

Increasing availability of genomic testing poses new challenges to clinicians, particularly where variant interpretation from commercial sources may be equivocal. The authors report a patient with recurrent rhabdomyosarcoma and subsequent bilateral breast cancer who was found to harbor a previously undescribed germline TP53 sequence alteration annotated by the commercial laboratory as a variant of uncertain significance. By investigating publicly available databases of aggregated normal germline and malignant somatic genomic sequences, the authors conclude that this missense variant, c.476C>T (p.A159V), is a novel, pathogenic Li-Fraumeni syndrome mutation and demonstrate the utility of these resources in clinical pediatric hematology and oncology practice.

Thrombopoietin Receptor Agonist Use in Children: Data From the Pediatric ITP Consortium of North America ICON2 Study.

BACKGROUND: Data on second-line treatment options for pediatric patients with immune thrombocytopenia (ITP) are limited. Thrombopoietin receptor agonists (TPO-RA) provide a nonimmunosuppressive option for children who require an increased platelet count. PROCEDURE: We performed a multicenter retrospective study of pediatric ITP patients followed at ITP Consortium of North America (ICON) sites to characterize TPO-RA use. RESULTS: Seventy-nine children had a total of 87 treatments (28 eltrombopag, 43 romiplostim, and eight trialed on both). The majority had primary ITP (82%) and most (60.8%) had chronic ITP. However, 22% had persistent ITP and 18% had newly diagnosed ITP. During the first 3 months of treatment, 89% achieved a platelet count ≥ 50 × 10(9) /l (86% romiplostim, 81% eltrombopag, P = 0.26) at least once in the absence of rescue therapy. The average time to a response was 6.4 weeks for romiplostim and 7.0 weeks for eltrombopag (P = 0.83). Only 40% of patients demonstrated a stable response with consistent dosing over time. An intermittent response with constant dose titration was seen in 15%, and an initial response that waned to no response was seen in 13%. Significant adverse events were minimal with the exception of two patients with thrombotic events and one who developed a neutralizing antibody. CONCLUSIONS: Our results demonstrate that TPO-RA agents are being used in children with ITP of varying duration and severity. The response was similar to clinical trials, but the sustainability of response varied. Future studies need to focus on the ideal timing and rationale for these medications in pediatric patients.

Nutlin-3 treatment spares cisplatin-induced inhibition of bone healing while maintaining osteosarcoma toxicity.

The majority of Osteosarcoma (OS) patients are treated with a combination of chemotherapy, resection, and limb salvage protocols. These protocols include distraction osteogenesis (DO), which is characterized by direct new bone formation. Cisplatin (CDP) is extensively used for OS chemotherapy and recent studies, using a mouse DO model, have demonstrated that CDP has profound negative effects on bone repair. Recent oncological therapeutic strategies are based on the use of standard cytotoxic drugs plus an assortment of biologic agents. Here we demonstrate that the previously reported CDP-associated inhibition of bone repair can be modulated by the administration of a small molecule p53 inducer (nutlin-3). The effects of nutlin-3 on CDP osteotoxicity were studied using both pre- and post-operative treatment models. In both cases the addition of nutlin-3, bracketing CDP exposure, demonstrated robust and significant bone sparing activity (p < 0.01-0.001). In addition the combination of nutlin-3 and CDP induced equivalent OS tumor killing in a xenograft model. Collectively, these results demonstrate that the induction of p53 peri-operatively protects bone healing from the toxic effects of CDP, while maintaining OS toxicity. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1716-1724, 2016.

The genomic landscape of juvenile myelomonocytic leukemia.

Juvenile myelomonocytic leukemia (JMML) is a myeloproliferative neoplasm (MPN) of childhood with a poor prognosis. Mutations in NF1, NRAS, KRAS, PTPN11 or CBL occur in 85% of patients, yet there are currently no risk stratification algorithms capable of predicting which patients will be refractory to conventional treatment and could therefore be candidates for experimental therapies. In addition, few molecular pathways aside from the RAS-MAPK pathway have been identified that could serve as the basis for such novel therapeutic strategies. We therefore sought to genomically characterize serial samples from patients at diagnosis through relapse and transformation to acute myeloid leukemia to expand knowledge of the mutational spectrum in JMML. We identified recurrent mutations in genes involved in signal transduction, splicing, Polycomb repressive complex 2 (PRC2) and transcription. Notably, the number of somatic alterations present at diagnosis appears to be the major determinant of outcome.

Risk organ + LCH gets the one-two punch?

In this issue of Blood, Donadieu et al present what may be the most encouraging data to date on a group of patients with Langerhans cell histiocytosis (LCH), which historically has poor disease-free survival and poor overall survival.

Dissecting the heterogeneity of macrophage activation syndrome complicating systemic juvenile idiopathic arthritis.

OBJECTIVE: To seek insights into the heterogeneity of macrophage activation syndrome (MAS) complicating systemic juvenile idiopathic arthritis (sJIA) through the analysis of a large patient sample collected in a multinational survey. METHODS: International pediatric rheumatologists and hemato-oncologists entered their patient data, collected retrospectively, in a Web-based database. The demographic, clinical, laboratory, histopathologic, therapeutic, and outcome data were analyzed in relation to (1) geographic location of caring hospital, (2) subspecialty of attending physician, (3) demonstration of hemophagocytosis, and (4) severity of clinical course. RESULTS: A total of 362 patients were included by 95 investigators from 33 countries. Demographic, clinical, laboratory, and histopathologic features were comparable among patients seen in diverse geographic areas or by different pediatric specialists. Patients seen in North America were given biologics more frequently. Patients entered by pediatric hemato-oncologists were treated more commonly with biologics and etoposide, whereas patients seen by pediatric rheumatologists more frequently received cyclosporine. Patients with demonstration of hemophagocytosis had shorter duration of sJIA at MAS onset, higher prevalence of hepatosplenomegaly, lower levels of platelets and fibrinogen, and were more frequently administered cyclosporine, intravenous immunoglobulin (IVIG), and etoposide. Patients with severe course were older, had longer duration of sJIA at MAS onset, had more full-blown clinical picture, and were more commonly given cyclosporine, IVIG, and etoposide. CONCLUSION: The clinical spectrum of MAS is comparable across patients seen in different geographic settings or by diverse pediatric subspecialists. There was a disparity in the therapeutic choices among physicians that underscores the need to establish uniform therapeutic protocols.

Long-term use of the thrombopoietin-mimetic romiplostim in children with severe chronic immune thrombocytopenia (ITP).

BACKGROUND: Treatment of chronic severe pediatric ITP is not well studied. In a phase 1/2 12-16-week study, 15/17 romiplostim-treated patients achieved platelet counts ≥50 × 109 /L, and romiplostim treatment was well tolerated. In a subsequent open-label extension (≤109 weeks), 20/22 patients received romiplostim; all achieved platelet counts >50 × 109 /L. Twelve patients continued in a second extension (≤127 weeks). Longitudinal data from start of romiplostim treatment through the two extensions were evaluated to investigate the safety and efficacy of long-term romiplostim treatment in chronic severe pediatric ITP. PROCEDURE: Patients received weekly subcutaneous romiplostim, adjusted by 1 µg/kg/week to maintain platelet counts (50-200 × 109 /L, maximum dose 10 µg/kg). Bone marrow examinations were not required. RESULTS: At baseline, patients were median age 10.0 years; median ITP duration 2.4 years; median platelet count 13 × 109 /L; 73% were male; and 36% had prior splenectomy. Median romiplostim treatment duration was 167 weeks (Q1, Q3: 78,227 weeks), and median average weekly dose was 5.4 µg/kg (Q1, Q3: 4.3, 8.0 µg/kg). Seven patients discontinued treatment: four withdrew consent, two were noncompliant, and one received alternative therapy. None withdrew because of adverse events (AEs). After the first 12 weeks, median platelet counts remained >50 × 109 /L. Eight (36.4%) patients received rescue medication, and 14 (63.6%) used concurrent ITP therapy. Seven patients (31.8%) reported serious AEs, and two (9.1%) reported life-threatening AEs (both thrombocytopenia); there were no serious AEs attributed to treatment and no fatalities. CONCLUSIONS: Long-term romiplostim treatment in this small cohort increased and maintained platelet counts for over 4 years in children with ITP with good tolerability and without significant toxicity. Pediatr Blood Cancer 2015;62:208-213. © 2014. The Authors. Pediatr Blood & Cancer published by Wiley Periodicals, Inc.

von Willebrand factor multimers in pediatric extracorporeal membrane oxygenation support.

Acquired von Willebrand factor (vWF) disease is associated with a decrease in the amount of circulating high molecular weight (HMW) vWF multimers. vWF has not been previously investigated in children on extracorporeal membrane oxygenation (ECMO) support. We hypothesized that HMW vWF multimers and vWF activity decrease over the course of ECMO support in these patients. This prospective, single center, observational, cohort pilot study was carried out between December 2010 and April 2011 and included patients 0 to 18 years old requiring ECMO support at our institution. Blood samples were tested for various aspects of vWF. Mean and standard deviation were estimated for vWF activity and multimers, whereas a generalized linear model was developed to estimate multimer changes over time.The study included six pediatric patients. The mean age of the patients was 54.9 ± 55.3 (mean ± standard deviation) months. The mean HMW vWF multimer percentage was 23.4 ± 7.3 in the pre-ECMO samples and significantly decreased over time (p<0.003). There was no significant change in low molecular weight vWF multimer percentage. An immediate decrease in vWF HMW multimers as a percentage of all multimers once ECMO is initiated was noted and persisted across the study period.

Cisplatin inhibits bone healing during distraction osteogenesis.

Osteosarcoma (OS) is the most common malignant bone tumor affecting children and adolescents. Many patients are treated with a combination of chemotherapy, resection, and limb salvage protocols. Surgical reconstructions after tumor resection include structural allografts, non-cemented endoprostheses, and distraction osteogenesis (DO), which require direct bone formation. Although cisplatin (CDP) is extensively used for OS chemotherapy, the effects on bone regeneration are not well studied. The effects of CDP on direct bone formation in DO were compared using two dosing regimens and both C57BL/6 (B6) and tumor necrosis factor receptor 1 knockout (TNFR1KO) mice, as CDP toxicity is associated with elevated TNF levels. Detailed evaluation of the five-dose CDP regimen (2 mg/kg/day), demonstrated significant decreases in new bone formation in the DO gaps of CDP treated versus vehicle treated mice (p < 0.001). Further, no significant inhibitory effects from the five-dose CDP regimen were observed in TNFR1KO mice. The two-dose regimen significantly inhibited new bone formation in B6 mice. These results demonstrate that CDP has profound short term negative effects on the process of bone repair in DO. These data provide the mechanistic basis for modeling peri-operative chemotherapy doses and schedules and may provide new opportunities to identify molecules that spare normal cells from the inhibitory effects of CDP.

A genome-wide association study of resistance to HIV infection in highly exposed uninfected individuals with hemophilia A.

Human genetic variation contributes to differences in susceptibility to HIV-1 infection. To search for novel host resistance factors, we performed a genome-wide association study (GWAS) in hemophilia patients highly exposed to potentially contaminated factor VIII infusions. Individuals with hemophilia A and a documented history of factor VIII infusions before the introduction of viral inactivation procedures (1979-1984) were recruited from 36 hemophilia treatment centers (HTCs), and their genome-wide genetic variants were compared with those from matched HIV-infected individuals. Homozygous carriers of known CCR5 resistance mutations were excluded. Single nucleotide polymorphisms (SNPs) and inferred copy number variants (CNVs) were tested using logistic regression. In addition, we performed a pathway enrichment analysis, a heritability analysis, and a search for epistatic interactions with CCR5 Δ32 heterozygosity. A total of 560 HIV-uninfected cases were recruited: 36 (6.4%) were homozygous for CCR5 Δ32 or m303. After quality control and SNP imputation, we tested 1 081 435 SNPs and 3686 CNVs for association with HIV-1 serostatus in 431 cases and 765 HIV-infected controls. No SNP or CNV reached genome-wide significance. The additional analyses did not reveal any strong genetic effect. Highly exposed, yet uninfected hemophiliacs form an ideal study group to investigate host resistance factors. Using a genome-wide approach, we did not detect any significant associations between SNPs and HIV-1 susceptibility, indicating that common genetic variants of major effect are unlikely to explain the observed resistance phenotype in this population.

Response to steroids predicts response to rituximab in pediatric chronic immune thrombocytopenia.

BACKGROUND: Treatment choice in pediatric immune thrombocytopenia (ITP) is arbitrary, because few studies are powered to identify predictors of therapy response. Increasingly, rituximab is becoming a treatment of choice in those refractory to other therapies. METHODS: The objective of this study was to evaluate univariate and multivariable predictors of platelet count response to rituximab. After local IRB approval, 565 patients with chronic ITP enrolled and met criteria for this study in the longitudinal, North American Chronic ITP Registry (NACIR) between January 2004 and October 2010. Treatment response was defined as a post-treatment platelet count ≥ 50,000/µl within 16 weeks of rituximab and 14 days of steroids. Treatment response data were captured both retrospectively at enrollment and then prospectively. RESULTS: Eighty (14.2%) patients were treated with rituximab with an overall response rate of 63.8% (51/80). Univariate correlates of response to rituximab included the presence of secondary ITP and a positive response to steroids. In multivariable analysis, response to steroids remained a strong correlate of response to rituximab, OR 6.8 (95% CI 2.0-23.0, P = 0.002). Secondary ITP also remained a strong predictor of response to rituximab, OR 5.6 (95% CI 1.1-28.6, P = 0.04). Although 87.5% of patients who responded to steroids responded to rituximab, 48% with a negative response to steroids did respond to rituximab. CONCLUSION: In the NACIR, response to steroids and presence of secondary ITP were strong correlates of response to rituximab, a finding not previously reported in children or adults.

Bleeding disorders: when is normal bleeding not normal?

Bleeding is a common event in many people, but when is it abnormal and when should further evaluation and diagnostic testing be performed? This review will highlight the three most common bleeding disorders and briefly describe their more common forms of presentation and management options. We will also discuss the role of local hemophilia treatment centers in assisting physicians around the state in managing these complex patients.

Phase II study of clofarabine in pediatric patients with refractory or relapsed acute myeloid leukemia.

PURPOSE: To determine the efficacy and safety of clofarabine in pediatric patients with refractory or relapsed acute myeloid leukemia (AML). PATIENTS AND METHODS: A phase II, open-label, multicenter study was conducted with single-agent clofarabine in pediatric patients with refractory or relapsed AML. Clofarabine was administered intravenously over 2 hours at the pediatric maximum-tolerated dose (MTD) of 52 mg/m(2) daily for 5 consecutive days. Cycles were repeated every 2 to 6 weeks. Responses determined by an independent response review panel. RESULTS: The 42 patients treated on the study had a median age of 13 years (range, 2 to 22 years) and had received a median number of two (range, one to five) prior regimens. The response rate was 26% and included one complete response without platelet recovery and 10 partial responses. The median duration of response was 20 weeks (range, 2 to >or= 156 weeks). Six of 28 patients who were refractory to the immediately preceding therapy achieved response. Thirteen patients (31%), including seven responders, proceeded to hematopoietic stem-cell transplantation (HSCT) after treatment with clofarabine and survived between 24 to >or= 160 weeks. Five patients (12%) remain alive post-transplantation at >or= 63, >or= 71, >or= 86, >or= 114, and >or= 130 weeks. The most common grade 3 or greater adverse events without regard to causality were febrile neutropenia, catheter-related infection, epistaxis, hypotension, nausea, and fever. Transient elevation of liver enzymes and hypokalemia occurred frequently. Five patients died within 30 days of clofarabine administration secondary to progressive disease, and another five died as a result of an adverse event. CONCLUSION: Clofarabine is active in pediatric patients with multiply relapsed or refractory AML. Responses allowed several refractory patients to proceed to HSCT. The toxicity profile was expected in this patient population.

Cardiomyopathy in children with Down syndrome treated for acute myeloid leukemia: a report from the Children's Oncology Group Study POG 9421.

PURPOSE: To determine the outcomes, with particular attention to toxicity, of children with Down syndrome (DS) and acute myeloid leukemia (AML) treated on Pediatric Oncology Group (POG) protocol 9421. PATIENTS AND METHODS: Children with DS and newly diagnosed AML (n = 57) were prospectively enrolled onto the standard-therapy arm of POG 9421 and were administered five cycles of chemotherapy, which included daunorubicin 135 mg/m(2) and mitoxantrone 80 mg/m(2). Outcomes and toxicity were evaluated prospectively and were compared with the non-DS-AML cohort (n = 565). A retrospective chart review was performed to identify adverse cardiac events. RESULTS: In the DS-AML group, 54 patients (94.7%) entered remission. One experienced induction failure and two died. Of the 54 who entered remission, three relapsed and six died as a result of other causes. The remission induction rate was similar in the non-DS-French-American-British (FAB) M7 (91.7%) and non-DS-non-M7 (89.3%) groups. The 5-year overall survival was significantly better in the DS-AML group (78.6%) than in the non-DS-M7 (36.3%) or the non-DS-non-M7 (51.8%) groups (P < .001). No age-related difference in 5-year, event-free survival was seen between patients younger than 2 years (75.8%) and those aged 2 to 4 years (78.3%). Symptomatic cardiomyopathy developed in 10 patients (17.5%) with DS-AML during or soon after completion of treatment; three died as a result of congestive heart failure. CONCLUSION: The POG 9421 treatment regimen was highly effective in both remission induction and disease-free survival for patients with DS-AML. However, there was a high incidence of cardiomyopathy, which supports current strategies for dose reduction of anthracyclines in this patient population.

Treatment of deep vein thrombosis with enoxaparin in pediatric cancer patients receiving chemotherapy.

There are few data regarding the use of enoxaparin in children undergoing myelosuppressive therapy for malignancies even though thrombosis is a known risk in pediatric patients with malignancies. Low-molecular-weight heparin such as enoxaparin has become widely used in adult patients with thrombosis. The purpose of this study was to review the utilization of low-molecular-weight heparin, enoxaparin (Lovenox), in children with cancer at our institution who had thrombosis while undergoing myelosuppressive chemotherapy. In particular we were interested in the efficacy of enoxaparin in these patients, and in whether these children were able to continue their chemotherapy without adjustment or interruption secondary to bleeding complications. We conducted a retrospective review from 1999 through April 1, 2004. Seven patients (4-17 years of age) were identified. Diagnosis included B-precursor acute lymphoblastic leukemia (ALL) (n=three), T-ALL, Hodgkin's disease, anaplastic large cell lymphoma, and rhabdomyosarcoma (n=one each). Six patients had a deep vein thrombus (DVT) or clot of the vena cava. One of these six patients also had a pulmonary embolus. One patient presented with manifestations of a unilateral cerebral vascular accident without evidence of DVT. Most patients were screened for known hypercoaguable abnormalities. Treatment was enoxaparin, 1-1.5 mg/kg/dose twice daily to maintain a heparin anti-Xa level of 0.5-1.5 IU/mL till clot resolution. The dose was then decreased to daily for a total of 3-6 months of therapy. All patients had resolution of their thrombosis within 1-2 months of initiation of enoxaparin, and none required delays or dose reduction of their chemotherapy regimens while on anticoagulation, though some were supported by blood and platelet transfusions. Enoxaparin was safely administered to this series of seven patients for thrombotic complications in children undergoing cancer chemotherapy.

Use of FEIBA for invasive or surgical procedures in patients with severe hemophilia A or B with inhibitors.

Achieving hemostasis in patients with hemophilia A or B is complicated by the presence of inhibitors and is made even more difficult when these individuals require surgery. Over a 4-year period, 6 patients with inhibitors to factor VIII and 1 patient with inhibitors to factor IX underwent surgery or invasive procedures at our institution. A total of 26 procedures were performed, primarily using the bypassing agent FEIBA for bleeding control. Excellent hemostasis was obtained in all cases, adding to accumulating data indicating that FEIBA is safe and effective in hemophilia patients with inhibitors who require surgery.