Gene Therapy in Hemophilia A: Achievements, Challenges, and Perspectives.

Strides in advancements of care of persons with hemophilia include development of long-acting factor replacement therapies, novel substitution and hemostatic rebalancing agents, and most recently approved gene therapy. Several decades of preclinical and clinical trials have led to development of adeno-associated viral (AAV) vector-mediated gene transfer for endogenous production of factor VIII (FVIII) in hemophilia A (HA). Only one gene therapy product for HA (valoctocogene roxaparvovec) has been approved by regulatory authorities. Results of valoctocogene roxaparvovec trial show significant improvement in bleeding rates and use of factor replacement therapy; however, sustainability and duration of response show variability with overall decline in FVIII expression over time. Further challenges include untoward adverse effects involving liver toxicity requiring immunosuppression and development of neutralizing antibodies to AAV vector rendering future doses ineffective. Real-life applicability of gene therapy for HA will require appropriate patient screening, infrastructure setup, long-term monitoring including data collection of patient-reported outcomes and innovative payment schemes. This review article highlights the success and development of HA gene therapy trials, challenges including adverse outcomes and variability of response, and perspectives on approach to gene therapy including shared decision-making and need for future strategies to overcome the several unmet needs.

Social Determinants of Health and Informed Consent Comprehension for Pediatric Cancer Clinical Trials.

Importance: Ensuring valid informed consent (IC) prior to enrollment in clinical trials is a fundamental ethical right. Objective: To assess whether social determinants of health (SDOH) and related sociocontextual factors are associated with parental IC comprehension in therapeutic childhood cancer clinical trials. Design, Setting, and Participants: This cross-sectional study prospectively enrolled 223 parents of children with newly diagnosed cancer at Rady Children's Hospital San Diego, a large quaternary academic center in California, from October 1, 2014, to March 31, 2021. Linear mixed effects models were used to assess whether IC comprehension overall and by domain (purpose, procedures, and randomization; risks and benefits; alternatives; and voluntariness) were associated with SDOH and sociocontextual factors. Data were analyzed from January 1, 2022, to July 31, 2023. Exposures: Informed consent for a therapeutic childhood cancer clinical trial. Main Outcomes and Measures: The primary outcome of interest was IC comprehension and its associations with SDOH (marital status, language, educational attainment, employment, insurance type, socioeconomic status, and health literacy) and sociocontextual factors (ethnicity, satisfaction with informed consent, and cancer type). Results: Of 223 parents, 172 (77.1%) were aged 18 to 44 years, 111 (49.8%) were Hispanic, 152 (68.2%) were women, and 163 (73.1%) were married. In terms of race, 2 (0.9%) were American Indian or Alaska Native, 22 (9.9%) were Asian or Pacific Islander, 8 (3.6%) were Black, 149 (66.8%) were White, and 42 (18.8%) were more than 1 race. In multivariable linear mixed-effects analyses, limited vs adequate health literacy was associated with lower comprehension of informed consent overall (mean [SD], 68.28 [11.81] vs 79.24 [11.77]; ß estimate, -9.02 [95% CI, -12.0 to -6.07]; P < .001) and with lower comprehension of the purpose, procedures, and randomization (mean [SD], 65.00 [12.64] vs 76.14 [11.53]; ß estimate, -7.87 [95% CI, -10.9 to -4.85]; P < .001); risks and benefits (mean [SD], 62.84 [20.24] vs 73.14 [20.86]; ß estimate, -10.1 [95% CI, -15.6 to -4.59]; P < .001); alternatives (mean [SD], 54.27 [43.18] vs 82.98 [34.24]; ß estimate, -14.3 [95% CI, -26.1 to -2.62]; P .02); and voluntariness (mean [SD], 76.52 [24.33] vs 95.39 [13.89]; ß estimate, -9.14 [95% CI, -14.9 to -3.44]; P = .002) domains. Use of Spanish vs English language for medical communication was associated with lower comprehension overall (mean [SD], 66.45 [12.32] vs 77.25 [12.18]; ß estimate, -5.30 [95% CI, -9.27 to -1.34]; P = .01) and with lower comprehension of the purpose, procedures, and randomization (mean [SD], 63.33 [11.98] vs 74.07 [12.52]; ß estimate, -4.33 [95% CI, -8.43 to -0.23]; P = .04) and voluntariness (mean [SD], 70.83 [24.02] vs 92.54 [17.27]; ß estimate, -9.69 [95% CI, -16.8 to -2.56]; P = .009) domains. Conclusions and Relevance: In this cross-sectional study including parents of children with newly diagnosed cancer who provided IC for their child's participation in a therapeutic clinical trial, limited health literacy and use of Spanish language for medical communication were associated with lower comprehension of IC. These findings suggest that, in this setting, parents with limited health literacy or those who use Spanish language for medical communication may not fully comprehend IC and therefore may not make truly informed decisions. These findings support the investigation of interventions, across pediatric disciplines, tailored to the participant's language and health literacy level to improve IC comprehension, particularly in racial and ethnic minority populations.

Consensus definition of essential, optimal, and suggested components of a pediatric sickle cell disease center.

Sickle cell disease (SCD) requires coordinated, specialized medical care for optimal outcomes. There are no United States (US) guidelines that define a pediatric comprehensive SCD program. We report a modified Delphi consensus-seeking process to determine essential, optimal, and suggested elements of a comprehensive pediatric SCD center. Nineteen pediatric SCD specialists participated from the US. Consensus was predefined as 2/3 agreement on each element's categorization. Twenty-six elements were considered essential (required for guideline-based SCD care), 10 were optimal (recommended but not required), and five were suggested. This work lays the foundation for a formal recognition process of pediatric comprehensive SCD centers.

Results of an international survey on adherence with anticoagulation in children, adolescents, and young adults: Communication from the ISTH SSC Subcommittee on Pediatric and Neonatal Thrombosis and Hemostasis.

BACKGROUND: The ISTH Scientific and Standardization Committee (SSC) Subcommittee on Pediatric/Neonatal Thrombosis and Hemostasis convened a working group on medication adherence to begin to understand the current state of clinical practice to inform priority areas for efforts to improve adherence for children, and adolescents and young adults (AYA) prescribed anticoagulants. OBJECTIVES: We sought to survey an international group of clinicians involved in anticoagulation management in children and/or AYA about perceptions of medication on health outcomes, clinical practice related to medication adherence, and barriers to assessing and improving medication adherence. METHODS: Clinicians involved in anticoagulation management in children and/or AYA were surveyed via REDCap® . Descriptive statistics were used to summarize demographic and clinical characteristics and responses to multiple choice and Likert-type questions. Free-text answers were coded based on the Behaviour Change Technique Taxonomy and the Expert Recommendations for Implement Change project. RESULTS AND CONCLUSIONS: There were 200 participants, 90% of whom were pediatric hematology/oncology physicians. Based on the results, which demonstrate that clinicians are concerned about impact of poor medication adherence and have limited resources to identify and improve adherence, the working group has identified next steps to further understand impact of medication adherence on anticoagulation-related health outcomes, address the need for validated measures to assess medication adherence for all anticoagulants prescribed to this population, and develop an intervention and implementation research agenda to improve outcomes.

Improving vitamin D testing and supplementation in children with newly diagnosed cancer: A quality improvement initiative at Rady Children's Hospital San Diego.

BACKGROUND: Vitamin D deficiency and insufficiency have been associated with poorer health outcomes. Children with cancer are at high risk for vitamin D deficiency and insufficiency. At our institution, we identified high variability in vitamin D testing and supplementation in this population. Of those tested, 65% were vitamin D deficient/insufficient. We conducted a quality improvement (QI) initiative with aim to improve vitamin D testing and supplementation among children aged 2-18 years with newly diagnosed cancer to ≥80% over 6 months. METHODS: An inter-professional team reviewed baseline data, then developed and implemented interventions using Plan-Do-Study-Act (PDSA) cycles. Barriers were identified using QI tools, including lack of automated triggers for testing and inconsistent supplementation criteria and follow-up testing post supplementation. Interventions included an institutional vitamin D guideline, clinical decision-making tree for vitamin D deficiency, insufficiency and sufficiency, electronic medical record triggers, and automated testing options. RESULTS: Baseline: N = 26 patients, four (15%) had baseline vitamin D testing; two (8%) received appropriate supplementation. Postintervention: N = 33 patients; 32 (97%) had baseline vitamin D testing; 33 (100%) received appropriate supplementation and completed follow-up testing timely (6-8 weeks post supplementation). Change was sustained over 24 months. CONCLUSIONS: We achieved and sustained our aim for vitamin D testing and supplementation in children with newly diagnosed cancer through inter-professional collaboration of hematology/oncology, endocrinology, hospital medicine, pharmacy, nursing, and information technology. Future PDSA cycles will address patient compliance with vitamin D supplementation and impact on patients' vitamin D levels.

Assessment of Factors Associated With Parental Perceptions of Voluntary Decisions About Child Participation in Leukemia Clinical Trials.

Importance: Obtaining voluntary informed consent prior to enrollment in clinical trials is a fundamental ethical requirement. Objective: To assess whether health literacy, contextual factors, or sociodemographic characteristics are associated with perception of voluntariness among parents who had consented for their child's participation in a leukemia therapeutic clinical trial. Design, Setting, and Participants: This cross-sectional study prospectively enrolled 97 parents of children diagnosed as having leukemia at Rady Children's Hospital San Diego, a large tertiary academic center in California, from 2014 to 2017. Health literacy, contextual factors (acculturation, decisional regret, and satisfaction with informed consent), sociodemographic characteristics, and perception of voluntariness after consenting for a therapeutic clinical trial were measured. Univariable and multivariable regression were used to determine significant associations. The analyses for the present study were conducted from May 2019 to May 2020. Exposures: Informed consent for a therapeutic leukemia clinical trial. Main Outcomes and Measures: The primary outcome of interest was perception of voluntariness and its associations with health literacy and other contextual factors (acculturation, decisional regret, and satisfaction with informed consent) and sociodemographic characteristics, including age, race/ethnicity, parental language, educational level, insurance type, marital status, and socioeconomic status. Results: Of 97 parents included, the majority were women (65 [67%]), married (71 [73%]), and of self-reported Hispanic ethnicity (50 [52%]). Lower perception of voluntariness was significantly associated with lower health literacy (r = 0.30; 95% CI, 0.11-0.47; P = .004), Spanish language (x̅ = -4.50, P = .05), lower acculturation if of Hispanic ethnicity (r = 0.30; 95% CI, 0.02-0.54; P = .05), greater decisional regret (r = -0.54; 95% CI, -0.67 to -0.38; P < .001), and lower satisfaction with informed consent (r = 0.39; 95% CI, 0.21-0.54; P < .001) in univariable analysis. Lower health literacy remained significantly associated with lower perception of voluntariness in multivariable analysis after adjustment for contextual factors and sociodemographic characteristics (ß = 4.06; 95% CI, 1.60-6.53; P = .001). Lower health literacy was significantly associated with Hispanic ethnicity (mean, 4.16; 95% CI, 3.75-4.57; P < .001), Spanish language spoken at home (mean, 3.17; 95% CI, 1.94-4.40; P < .001), high school or less educational level (mean, 3.41; 95% CI, 2.83-3.99; P < .001), public insurance (mean, 4.00; 95% CI, 3.55-4.45; P < .001), and unmarried status (mean, 3.71; 95% CI, 2.91-4.51; P = .03). Conclusions and Relevance: Among parents of children with newly diagnosed leukemia who had consented for their child's participation in a therapeutic clinical trial, lower perception of voluntariness was significantly associated with lower health literacy. These results suggest that parents with low health literacy may perceive external influences in their decision for their child's participation in clinical trials. This finding highlights the potential role of recruitment interventions tailored to the participant's health literacy level to improve voluntary informed consent in underserved populations.

Etranacogene dezaparvovec for hemophilia B gene therapy.

The treatment landscape for hemophilia has been rapidly changing with introduction of novel therapies. Gene therapy for hemophilia is a promising therapeutic option for sustained endogenous factor production to mitigate the need for prophylactic treatment to prevent spontaneous and traumatic bleeding. Etranacogene dezaparvovec is an investigational factor IX (FIX) gene transfer product that utilizes the adeno-associated virus (AAV) 5 vector with a liver-specific promoter and a hyperactive FIX transgene. Here, the development of etranacogene dezaparvovec and available efficacy and safety data from clinical trials are reviewed. Overall, etranacogene dezaparvovec provides sustained FIX expression for more than 2 years and allows for a bleed and infusion-free life in the majority of patients. Safety, efficacy, and quality-of-life data will inform shared decision-making for patients who are considering gene therapy. Long-term follow-up regarding duration of expression and safety are crucial.

Factor IX Padua gene therapy to boost clotting factor and prevent bleeding for people living with hemophilia B People living with hemophilia have low or missing clotting factor, which can lead to bleeding that is unexpected or caused by a traumatic event (such as a sports injury or surgery). There are two main types of hemophilia: clotting factor (F)VIII deficiency (known as hemophilia A) and FIX deficiency (known as hemophilia B). People living with the severe or moderately severe forms of hemophilia (clotting factor levels below 3% of normal) need regular treatment, typically by infusions into the vein, to stop or prevent bleeding and damage to their joints. Gene therapy is currently being investigated as a new treatment option that introduces a working copy of the clotting factor gene to the liver. Following treatment, clotting factor is produced by the liver. Etranacogene dezaparvovec [Et-ra-na-co-gene dez-a-par-vo-vec] is a form of gene therapy for people living with hemophilia B. This form of gene therapy includes a modified form of FIX (FIX Padua) which produces high levels of FIX activity compared with normal FIX. It is being tested to see whether individuals will have low rates of bleeding and not need to treat themselves with clotting factor. In the clinical trials, participants with FIX levels below 2% (of normal) receive a single gene therapy infusion. The results of the trials have so far shown that patients given etranacogene dezaparvovec have continuous production of FIX, whereby they have reported much less bleeding and factor treatment. Questions relating to the safety of the gene therapy and how long it works will hopefully be answered through long-term follow-up of the patients once the trials are completed.

Diagnostic and Treatment Challenges for Acquired Hemophilia A in Pediatrics: Report of 2 Cases.

Acquired hemophilia A (AHA) occurs rarely in children. We report 2 cases of adolescent females with AHA. The first case underwent bone marrow aspiration/biopsy during workup, which was complicated by bleeding. Bleeding resolved after initiation of therapy with cyclophosphamide and glucocorticoid, but despite the addition of rituximab, she did not achieve complete remission until treatment with intravenous immunoglobulin. In the second case, we observed that a mixing study without incubation will not detect an acquired factor VIII inhibitor, but further workup based on suspicion for AHA led to the correct diagnosis. Both had significant medication toxicity which required treatment modification.

Improving Pediatric Neuro-Oncology Survival Disparities in the United States-Mexico Border Region: A Cross-Border Initiative Between San Diego, California, and Tijuana, Mexico.

PURPOSE: Treatment of children with CNS tumors (CNSTs) demands a complex, interdisciplinary approach that is rarely available in low- and middle-income countries. We established the Cross-Border Neuro-Oncology Program (CBNP) between Rady Children's Hospital, San Diego (RCHSD), and Hospital General, Tijuana (HGT), Mexico, to provide access to neuro-oncology care, including neurosurgic services, for children with CNSTs diagnosed at HGT. Our purpose was to assess the feasibility of the CBNP across the United States-Mexico border and improve survival for children with CNSTs at HGT by implementing the CBNP. PATIENTS AND METHODS: We prospectively assessed clinicopathologic profiles, the extent of resection, progression-free survival, and overall survival (OS) in children with CNSTs at HGT from 2010 to 2017. RESULTS: Sixty patients with CNSTs participated in the CBNP during the study period. The most common diagnoses were low-grade glioma (24.5%) and medulloblastoma (22.4%). Of patients who were eligible for surgery, 49 underwent resection at RCHSD and returned to HGT for collaborative management. Gross total resection was achieved in 78% of cases at RCHSD compared with 0% at HGT (P < .001) and was a predictor of 5-year OS (hazard ratio, 0.250; 95% CI, 0.067 to 0.934; P = .024). Five-year OS improved from 0% before 2010 to 52% in 2017. CONCLUSION: The CBNP facilitated access to complex neuro-oncology care for underserved children in Mexico through binational exchanges of resources and expertise. Survival for patients in the CBNP dramatically improved. Gross total resection at RCHSD was associated with higher OS, highlighting the critical role of experienced neurosurgeons in the treatment of CNSTs. The CBNP model offers an attractive alternative for children with CNSTs in low- and middle-income countries who require complex neuro-oncology care, particularly those in close proximity to institutions in high-income countries with extensive neuro-oncology expertise.

Sociodemographic and clinical characteristics associated with vitamin D status in newly diagnosed pediatric cancer patients.

Vitamin D deficiency and insufficiency are associated with serious sequelae in childhood cancer survivors. However, data on vitamin D deficiency in children with newly diagnosed cancer are scarce and the role of sociodemographic factors and vitamin D supplementation is largely unknown. We assessed vitamin D status and its socio-demographic and clinical correlates in 163 children with newly diagnosed cancer, using 25-hydroxy vitamin D (25(OH)D) concentrations and assessed longitudinal changes following vitamin D supplementation. Sixty-five percent of the patients with newly diagnosed cancer had low 25(OH)D concentrations. Fifty-two patients (32%) were vitamin D deficient (≤20 ng/mL 25(OH)D concentration), and 53(33%) were insufficient (21-29 ng/mL 25(OH)D concentration). Age over 10 (P = 0.019), Hispanic ethnicity (P = 0.002), and female sex (P = 0.008) were significantly associated with lower 25(OH)D concentration at diagnosis. Vitamin D supplementation resulted in significant increase in 25(OH)D concentrations (P < 0.001). However, following supplementation in the longitudinal analysis, this increase was less pronounced in Hispanic patients vs. non-Hispanic (P = 0.007), and in children with solid tumors vs. hematological malignancies (P = 0.003). Vitamin D deficiency and insufficiency are common in children with newly diagnosed cancer. Hispanic patients, females and older children were at higher risk for vitamin D deficiency and insufficiency. Although supplementation appeared to increase 25(OH)D concentrations over time, this increase was not as pronounced in certain subsets of patients. Prospective trials of the effects of vitamin D supplementation on bone health in children with newly diagnosed cancer are warranted, particularly in Hispanics and patients with solid tumors.

Management and outcomes of pediatric septic thrombophlebitis: a case series.

Septic thrombophlebitis is a potentially life-threatening condition. Pediatric hematologists are often consulted to provide recommendations regarding anticoagulation management. We conducted a ten-year retrospective, single-center study of hospitalized pediatric patients who were treated for septic thrombophlebitis. Our primary outcome was resolution of thrombophlebitis. Twenty-eight patients were included in the study. Eighty-nine percent of patients received both antibiotic and anticoagulation therapy. The median durations of intravenous and total antibiotic therapy were 47.5 days (range 14-120) and 65 days (range 14-281), respectively, and median duration of anticoagulation therapy was 92 days (range 41-268). Resolution of thrombosis defined by magnetic resonance imaging, computed tomography, or ultrasound imaging was documented in 16 of 28 (57%) patients. Despite the high rate of persistent thrombosis, there was a low risk of relapse of infection in cases where antibiotic and/or anticoagulation was discontinued prior to complete resolution of the thrombus. Further research is needed to determine if duration of antibiotic and/or anticoagulation treatment can be shortened.

The Evaluation of Hematologic Screening and Perioperative Management in Patients with Noonan Syndrome: A Retrospective Chart Review.

OBJECTIVES: To assess the potential impact of using screening recommendations for bleeding disorders in patients with Noonan syndrome on perioperative bleeding complications. STUDY DESIGN: We performed a retrospective, single-site cohort study; patients were identified by query of the electronic medical record. All patients with a clinical diagnosis of Noonan syndrome over a 10-year period were included. Data on surgeries, hematologic evaluation, bleeding symptoms, and bleeding complications were extracted. Surgeries were graded as major or minor. RESULTS: We identified 101 patients with Noonan syndrome, 70 of whom required surgery for a total of 164 procedures. Nine patients (9/70; 12.8%) had bleeding complications, occurring in those without comprehensive testing or perioperative intervention and undergoing major or dental surgery. Based on these findings, the risk of a bleeding complication for patients with Noonan syndrome who did not have comprehensive testing or perioperative intervention was 6.2% (95% CI 2.3%-10.1%), indicating the number needed to treat or screen would be 16 to prevent 1 bleeding complication (95% CI 9.9-43.9). The majority of patients had either no or incomplete evaluation (59 of 101; 58.4%). CONCLUSIONS: With proper evaluation and management, the bleeding risk in patients with Noonan syndrome can be minimized. Efforts are needed to address the knowledge and implementation gap in this evaluation.

How we approach: Training pediatric coagulationists.

Unique expertise is required for the care of children, adolescents, and young adults with bleeding and clotting disorders. A number of Hemophilia Treatment Centers have developed pediatric hemostasis and thrombosis fellowship programs to facilitate subspecialty training and recruitment and retention in this field. This manuscript reviews an approach to training pediatric coagulationists including a description of current programs, sample curriculum, funding sources, and expected outcomes.

Hematologic Manifestations of Nutritional Deficiencies: Early Recognition is Essential to Prevent Serious Complications.

Nutritional deficiencies, including deficiencies of vitamin B12, copper, and vitamin C, may result in cytopenias and hematologic symptoms. Early recognition of these deficiencies is imperative for prompt treatment and improvement in hematologic and other manifestations. We describe 5 cases which illustrate the hematologic manifestations of nutritional deficiencies and challenges to initial diagnosis and management. Supplementation of the deficient vitamin or micronutrient in all of these cases resulted in rapid resolution of cytopenias, hemorrhage, and other associated hematologic symptoms. We also review other nutritional deficiencies that manifest with hematologic symptoms and compile recommendations on treatment and expected time to response.

Venous Thromboembolism: A Survey of Oral Anticoagulant Preferences in the Treatment of Challenging Patient Populations.

Venous thromboembolism (VTE) is a highly morbid condition with several available oral anticoagulant treatment options. Numerous studies have been published comparing warfarin to direct oral anticoagulants; however, several populations remain underrepresented in these reports. We surveyed members of The Venous ThromboEmbolism Network U.S. working group regarding their oral anticoagulant preferences for the treatment of VTE in different and challenging populations. In individuals with VTE and no other medical comorbidities, respondents preferred either rivaroxaban (48.7%) or apixaban (48.7%). Apixaban (53.3%) was preferred in elderly individuals with an increased risk of bleeding. Warfarin was preferred in individuals with liver or kidney dysfunction (42% and 47%), altered metabolism (>55%), and antiphospholipid antibody syndrome (84.2%). Low-molecular-weight heparin was preferred in individuals with malignancy (56.6%), followed by edoxaban (23.7%). These findings may help guide clinicians when choosing an anticoagulant in these challenging situations and demonstrate the urgent need for additional study in these groups.

How I approach: Previously untreated patients with severe congenital hemophilia A.

Previously untreated patients with severe hemophilia A are a vulnerable population at risk for severe bleeding which is currently managed with exogenous clotting factor replacement. The primary burden of current treatment is high-titer inhibitor development. Evolving data on current treatment products as well as emerging therapeutics may inform treatment decisions to prevent bleeding and inhibitor formation. Considerations for diagnosis, education, and shared decision-making related to product choice and treatment regimen are discussed.

Children with sickle cell disease migrating to the United States from sub-Saharan Africa.

Sickle cell disease (SCD) is an inherited red blood cell disorder that occurs worldwide and results in significant morbidity and mortality. In addition to affected children who are born in the US, an increasing number of children with SCD are migrating to the US with their families or through international adoption. Children arriving as immigrants or refugees have unique medical and psychosocial challenges that require a multidisciplinary team approach which takes into account the family's primary language, culture, and health beliefs. This review focuses on the special challenges for children with SCD who emigrate from sub-Saharan Africa to the US.

Venous Thromboembolism in Children with Cancer and Blood Disorders.

Venous thromboembolism (VTE) in children is multifactorial and most often related to a combination of inherited and acquired thrombophilias. Children with cancer and blood disorders are often at risk for VTE due to disease-related factors such as inflammation and abnormal blood flow and treatment-related factors such as central venous catheters and surgery. We will review risk factors for VTE in children with leukemia, lymphoma, and solid tumors. We will also review risk factors for VTE in children with blood disorders with specific focus on sickle cell anemia and hemophilia. We will present the available evidence and clinical guidelines for prevention and treatment of VTE in these populations.