RESUMEN
Immune thrombocytopenia (ITP) is an autoimmune bleeding disorder affecting approximately 1 in 20 000 people. While most patients with ITP are successfully managed with the current set of standard and approved therapeutics, patients who cannot be adequately managed with these therapies, considered to have refractory ITP, are not uncommon. Therefore, there remains an ongoing need for novel therapeutics and drug development in ITP. Several agents exploiting novel targets and mechanisms in ITP are presently under clinical development, with trials primarily recruiting heavily pretreated patients and those with otherwise refractory disease. Such agents include the neonatal Fc receptor antagonist efgartigimod, the Bruton tyrosine kinase inhibitor rilzabrutinib, the complement inhibitors sutimlimab and iptacopan and anti-CD38 monoclonal antibodies such as daratumumab and mezagitamab, among others. Each of these agents exploits therapeutic targets or other aspects of ITP pathophysiology currently not targeted by the existing approved agents (thrombopoietin receptor agonists and fostamatinib). This manuscript offers an in-depth review of the current available data for novel therapeutics in ITP presently undergoing phase 2 or 3 studies in patients with heavily pretreated or refractory ITP. It additionally highlights the future directions for drug development in refractory ITP, including discussion of innovative clinical trial designs, health-related quality of life as an indispensable clinical trial end-point and balancing potential toxicities of drugs with their potential benefits in a bleeding disorder in which few patients suffer life-threatening bleeding.
Asunto(s)
Púrpura Trombocitopénica Idiopática , Trombocitopenia , Recién Nacido , Humanos , Púrpura Trombocitopénica Idiopática/tratamiento farmacológico , Calidad de Vida , Inactivadores del Complemento , Desarrollo de MedicamentosRESUMEN
BACKGROUND: Patients with transfusion-dependent ß-thalassemia need regular red-cell transfusions. Luspatercept, a recombinant fusion protein that binds to select transforming growth factor ß superfamily ligands, may enhance erythroid maturation and reduce the transfusion burden (the total number of red-cell units transfused) in such patients. METHODS: In this randomized, double-blind, phase 3 trial, we assigned, in a 2:1 ratio, adults with transfusion-dependent ß-thalassemia to receive best supportive care plus luspatercept (at a dose of 1.00 to 1.25 mg per kilogram of body weight) or placebo for at least 48 weeks. The primary end point was the percentage of patients who had a reduction in the transfusion burden of at least 33% from baseline during weeks 13 through 24 plus a reduction of at least 2 red-cell units over this 12-week interval. Other efficacy end points included reductions in the transfusion burden during any 12-week interval and results of iron studies. RESULTS: A total of 224 patients were assigned to the luspatercept group and 112 to the placebo group. Luspatercept or placebo was administered for a median of approximately 64 weeks in both groups. The percentage of patients who had a reduction in the transfusion burden of at least 33% from baseline during weeks 13 through 24 plus a reduction of at least 2 red-cell units over this 12-week interval was significantly greater in the luspatercept group than in the placebo group (21.4% vs. 4.5%, P<0.001). During any 12-week interval, the percentage of patients who had a reduction in transfusion burden of at least 33% was greater in the luspatercept group than in the placebo group (70.5% vs. 29.5%), as was the percentage of those who had a reduction of at least 50% (40.2% vs. 6.3%). The least-squares mean difference between the groups in serum ferritin levels at week 48 was -348 µg per liter (95% confidence interval, -517 to -179) in favor of luspatercept. Adverse events of transient bone pain, arthralgia, dizziness, hypertension, and hyperuricemia were more common with luspatercept than placebo. CONCLUSIONS: The percentage of patients with transfusion-dependent ß-thalassemia who had a reduction in transfusion burden was significantly greater in the luspatercept group than in the placebo group, and few adverse events led to the discontinuation of treatment. (Funded by Celgene and Acceleron Pharma; BELIEVE ClinicalTrials.gov number, NCT02604433; EudraCT number, 2015-003224-31.).
Asunto(s)
Receptores de Activinas Tipo II/uso terapéutico , Transfusión de Eritrocitos/estadística & datos numéricos , Hematínicos/uso terapéutico , Fragmentos Fc de Inmunoglobulinas/uso terapéutico , Proteínas Recombinantes de Fusión/uso terapéutico , Talasemia beta/tratamiento farmacológico , Receptores de Activinas Tipo II/efectos adversos , Adolescente , Adulto , Anciano , Método Doble Ciego , Femenino , Ferritinas/sangre , Hematínicos/efectos adversos , Humanos , Fragmentos Fc de Inmunoglobulinas/efectos adversos , Análisis de Intención de Tratar , Análisis de los Mínimos Cuadrados , Masculino , Persona de Mediana Edad , Oportunidad Relativa , Proteínas Recombinantes de Fusión/efectos adversos , Esplenectomía , Adulto Joven , Talasemia beta/genética , Talasemia beta/cirugía , Talasemia beta/terapiaRESUMEN
Adeno-associated virus (AAV)-mediated gene therapy is a novel treatment promising to reduce morbidity associated with hemophilia. Although multiple clinical trials continue to evaluate efficacy and safety, limited cost-effectiveness data have been published. This study compared the potential cost-effectiveness of AAV-mediated factor IX (FIX)-Padua gene therapy for patients with severe hemophilia B in the United States vs on-demand FIX replacement and primary FIX prophylaxis, using either standard or extended half-life FIX products. A microsimulation Markov model was constructed, and transition probabilities between health states and utilities were informed by using published data. Costs were aggregated by using a microcosting approach. A time horizon from 18 years old until death, from the perspective of a third-party payer in the United States, was conducted. Gene therapy was more cost-effective than both alternatives considering a $150 000/quality-adjusted life-year threshold. The price for gene therapy was assumed to be $2 000 000 in the base case scenario; however, one of the 1-way sensitivity analyses was conducted by using observed manufacturing, administration, and 5-year follow-up costs of $87 198 for AAV-mediated gene therapy vector as derived from the manufacturing facility and clinical practice at St Jude Children's Research Hospital. One-way sensitivity analyses revealed 10 of 102 scenarios in which gene therapy was not cost-effective compared with alternative treatments. Notably, gene therapy remained cost-effective in a hypothetical scenario in which we estimated that the discounted factor concentrate price was 20% of the wholesale acquisition cost in the United States. Probabilistic sensitivity analysis estimated gene therapy to be cost-effective at 92% of simulations considering a $150 000/quality-adjusted life-year threshold. In conclusion, based on detailed simulation inputs and assumptions, gene therapy was more cost-effective than on-demand treatment and prophylaxis for patients with severe hemophilia B.
Asunto(s)
Terapia Genética/economía , Hemofilia B/terapia , Adulto , Simulación por Computador , Análisis Costo-Beneficio , Hemofilia B/economía , Hemofilia B/epidemiología , Humanos , Cadenas de Markov , Probabilidad , Estados Unidos/epidemiologíaRESUMEN
BACKGROUND: Patients with transfusion-dependent (TD) ß-thalassemia require long-term red blood cell transfusions (RBCTs) that lead to iron overload, impacting health-related quality of life (HRQoL). METHODS: The impact of luspatercept, a first-in-class erythroid maturation agent, versus placebo on HRQoL of patients with TD ß-thalassemia was evaluated in the phase 3 BELIEVE trial. HRQoL was assessed at baseline and every 12 weeks using the 36-item Short Form Health Survey (SF-36) and Transfusion-dependent Quality of Life questionnaire (TranQol). Mean change in HRQoL was evaluated from baseline to week 48 for patients receiving luspatercept + best supportive care (BSC) and placebo + BSC and between luspatercept responders and non-responders. RESULTS: Through week 48, for both groups, mean scores on SF-36 and TranQol domains were stable over time and did not have a clinically meaningful change. At week 48, more patients who achieved clinical response (≥50% reduction in RBCT burden over 24 weeks) in the luspatercept + BSC group had improvement in SF-36 Physical Function compared with placebo + BSC (27.1% vs. 11.5%; p = .019). CONCLUSIONS: Luspatercept + BSC reduced transfusion burden while maintaining patients' HRQoL. HRQoL domain improvements from baseline through 48 weeks were also enhanced for luspatercept responders.
Asunto(s)
Talasemia beta , Humanos , Receptores de Activinas Tipo II/uso terapéutico , Talasemia beta/tratamiento farmacológico , Fragmentos Fc de Inmunoglobulinas/uso terapéutico , Calidad de VidaRESUMEN
INTRODUCTION: Simoctocog alfa (Nuwiq®) is a 4th generation recombinant FVIII with proven efficacy for the prevention and treatment of bleeding episodes (BEs) in previously treated patients with severe haemophilia A. The NuProtect study assessed the immunogenicity, efficacy and safety of simoctocog alfa in 108 previously untreated patients (PUPs). The incidence of high-titre inhibitors was 16.2% and no patients with non-null F8 mutations developed inhibitors. AIM: To report the efficacy and safety results from the NuProtect study. METHODS: PUPs received simoctocog alfa for prophylaxis, treatment of BEs, or as surgical prophylaxis. The efficacy of prophylaxis (during inhibitor-free periods) was assessed using annualised bleeding rates (ABRs). The efficacy in treating BEs and in surgical prophylaxis was assessed using a 4-point scale. Adverse events were recorded throughout the study. RESULTS: Of 108 PUPs treated with simoctocog alfa, 103 received at least one prophylactic dose and 50 received continuous prophylaxis for at least 24 weeks. In patients on continuous prophylaxis, the median ABR was 0 (mean 0.5) for spontaneous BEs and 2.5 (mean 3.6) for all BEs. In 85 patients who had BEs, efficacy of BE treatment was excellent or good for 92.9% (747/804) of rated BEs; 92.3% of BEs were treated with 1 or 2 infusions. The efficacy of surgical prophylaxis was excellent or good for 94.7% (18/19) of rated procedures. There were no safety concerns and no thromboembolic events. CONCLUSION: Simoctocog alfa was efficacious and well tolerated as prophylaxis, surgical prophylaxis and for the treatment of BEs in PUPs with severe haemophilia A.
Asunto(s)
Hemofilia A , Humanos , Hemofilia A/tratamiento farmacológico , Hemofilia A/cirugía , Factor VIII/efectos adversos , Factor VIII/genética , Hemorragia/prevención & control , Hemorragia/inducido químicamente , Resultado del TratamientoRESUMEN
Thalassaemia is caused by genetic globin defects leading to anaemia, transfusion-dependence and comorbidities. Reduced survival and systemic organ disease affect transfusion-dependent thalassaemia major and thalassaemia intermedia. Recent improvements in clinical management have reduced thalassaemia mortality. The therapeutic landscape of thalassaemia may soon include gene therapies as functional cures. An analysis of the adult US thalassaemia population has not been performed since the Thalassemia Clinical Research Network cohort study from 2000 to 2006. The Centers for Disease Control and Prevention supported US thalassaemia treatment centres (TTCs) to compile longitudinal information on individuals with thalassaemia. This dataset provided an opportunity to evaluate iron balance, chelation, comorbidities and demographics of adults with thalassaemia receiving care at TTCs. Two adult cohorts were compared: those over 40 years old (n = 75) and younger adults ages 18-39 (n = 201). The older adult cohort was characterized by higher numbers of iron-related comorbidities and transfusion-related complications. By contrast, younger adults had excess hepatic and cardiac iron and were receiving combination chelation therapy. The ethnic composition of the younger cohort was predominantly of Asian origin, reflecting the demographics of immigration. These findings demonstrate that comprehensive care and periodic surveys are needed to ensure optimal health and access to emerging therapies.
Asunto(s)
Talasemia/epidemiología , Adolescente , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Terapia Combinada/efectos adversos , Terapia Combinada/métodos , Comorbilidad , Manejo de la Enfermedad , Susceptibilidad a Enfermedades , Femenino , Predisposición Genética a la Enfermedad , Humanos , Sobrecarga de Hierro/diagnóstico , Sobrecarga de Hierro/etiología , Sobrecarga de Hierro/terapia , Masculino , Persona de Mediana Edad , Vigilancia en Salud Pública , Estudios Retrospectivos , Factores Sociodemográficos , Talasemia/diagnóstico , Talasemia/etiología , Talasemia/terapia , Estados Unidos/epidemiología , Adulto JovenRESUMEN
BACKGROUND: Extended half-life (EHL) factor VIII (FVIII) products may decrease the burden of prophylactic treatment in haemophilia A by reducing infusion frequency. However, these products still exhibit wide inter-patient variability and benefit from pharmacokinetic (PK) tailoring. OBJECTIVE: Identify limited sampling strategies for rFVIIIFc, an EHL FVIII product, that produce accurate estimates of PK parameters and relevant troughs. METHODS: We performed a limited sampling analysis on simulated populations of adults, adolescents, and children based on published population PK data. Sampling strategies were evaluated by comparing the error in estimates of half-life, clearance, and trough levels, to a full 6-sample design. Furthermore, we assessed the impact of incorporating knowledge about prior doses, and the day of the PK study within the regimen. We also evaluated the potential inappropriate dose adjustment rate (IDAR) among the modelled sampling strategies. RESULTS: Many sampling strategies, including several 2-sample designs, accurately predicted the PK and exposure measures (median absolute error <10%). When samples are only collected during a single visit (i.e., predose + peak), inclusion of prior dose information reduces median half-life error from >20% to ~5% for adults/adolescents. In this same scenario, appropriate scheduling of the PK study decreases likelihood of unmeasurable predose samples, reducing median error on the 72-h trough from 25% to <12% in the youngest population. CONCLUSIONS: The PK of rFVIIIFc can be accurately estimated using only peak and trough samples, provided that knowledge of prior doses is incorporated and the PK study is planned on an appropriate day within the dosing regimen.
Asunto(s)
Hemofilia A , Hemostáticos , Adolescente , Adulto , Niño , Factor VIII , Semivida , Hemofilia A/tratamiento farmacológico , HumanosRESUMEN
OBJECTIVES: Pyruvate kinase (PK) deficiency is caused by PKLR gene mutations, leading to defective red blood cell glycolysis and hemolytic anemia. Rates of comorbidities and complications by transfusion history and relative to the general population remain poorly quantified. METHODS: Data for patients aged ≥ 18 years with two confirmed PKLR mutations were obtained from the PK deficiency Natural History Study (NCT02053480). Frequencies of select conditions were compared with an age- and sex-matched cohort from a general insured US population without PK deficiency. RESULTS: Compared with the matched population (n = 1220), patients with PK deficiency (n = 122) had significantly higher lifetime rates of osteoporosis, liver cirrhosis, and pulmonary hypertension; splenectomy and cholecystectomy rates were also significantly higher in the 8 years before the index date. Sixty-five (53.3%) patients with PK deficiency were classified as regularly transfused, 30 (24.6%) as occasionally transfused, and 27 (22.1%) as never transfused. Regularly transfused patients were significantly more likely than never transfused patients to have had splenectomy, cholecystectomy, and/or thrombosis. Liver iron overload was reported in 62% of patients and occurred regardless of transfusion cohort. CONCLUSIONS: Even never transfused patients with PK deficiency had higher rates of select comorbidities and complications than individuals without PK deficiency.
Asunto(s)
Anemia Hemolítica Congénita no Esferocítica/epidemiología , Piruvato Quinasa/deficiencia , Errores Innatos del Metabolismo del Piruvato/epidemiología , Adulto , Alelos , Anemia Hemolítica Congénita no Esferocítica/etiología , Comorbilidad , Femenino , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Mutación , Prevalencia , Piruvato Quinasa/genética , Errores Innatos del Metabolismo del Piruvato/etiología , Adulto JovenRESUMEN
BACKGROUND: Pyruvate kinase deficiency (PKD) is a rare, autosomal recessive red blood cell enzyme disorder, which leads to lifelong hemolytic anemia and associated complications from the disease and its management. METHODS: An international, multicenter registry enrolled 124 individuals younger than 18 years old with molecularly confirmed PKD from 29 centers. Retrospective and prospective clinical data were collected. RESULTS: There was a wide range in the age at diagnosis from 0 to 16 years. Presentation in the newborn period ranged from asymptomatic to neonatal jaundice to fulminant presentations of fetal distress, myocardial depression, and/or liver failure. Children <5 years old were significantly more likely to be transfused than children >12 to <18 years (53% vs. 14%, p = .0006), which correlated with the timing of splenectomy. Regular transfusions were most common in children with two severe PKLR variants. In regularly transfused children, the nadir hemoglobin goal varied considerably. Impact on quality of life was a common reason for treatment with regular blood transfusions and splenectomy. Splenectomy increased the hemoglobin and decreased transfusion burden in most children but was associated with infection or sepsis (12%) and thrombosis (1.3%) even during childhood. Complication rates were high, including iron overload (48%), perinatal complications (31%), and gallstones (20%). CONCLUSIONS: There is a high burden of disease in children with PKD, with wide practice variation in monitoring and treatment. Clinicians must recognize the spectrum of the manifestations of PKD for early diagnostic testing, close monitoring, and management to avoid serious complications in childhood.
Asunto(s)
Anemia Hemolítica Congénita no Esferocítica , Piruvato Quinasa/deficiencia , Errores Innatos del Metabolismo del Piruvato , Adolescente , Anemia Hemolítica Congénita no Esferocítica/diagnóstico , Anemia Hemolítica Congénita no Esferocítica/genética , Anemia Hemolítica Congénita no Esferocítica/terapia , Niño , Preescolar , Humanos , Estudios Prospectivos , Errores Innatos del Metabolismo del Piruvato/diagnóstico , Errores Innatos del Metabolismo del Piruvato/genética , Errores Innatos del Metabolismo del Piruvato/terapia , Calidad de Vida , Estudios RetrospectivosRESUMEN
An international, multicenter registry was established to collect retrospective and prospective clinical data on patients with pyruvate kinase (PK) deficiency, the most common glycolytic defect causing congenital nonspherocytic hemolytic anemia. Medical history and laboratory and radiologic data were retrospectively collected at enrollment for 254 patients with molecularly confirmed PK deficiency. Perinatal complications were common, including anemia that required transfusions, hyperbilirubinemia, hydrops, and prematurity. Nearly all newborns were treated with phototherapy (93%), and many were treated with exchange transfusions (46%). Children age 5 years and younger were often transfused until splenectomy. Splenectomy (150 [59%] of 254 patients) was associated with a median increase in hemoglobin of 1.6 g/dL and a decreased transfusion burden in 90% of patients. Predictors of a response to splenectomy included higher presplenectomy hemoglobin (P = .007), lower indirect bilirubin (P = .005), and missense PKLR mutations (P = .0017). Postsplenectomy thrombosis was reported in 11% of patients. The most frequent complications included iron overload (48%) and gallstones (45%), but other complications such as aplastic crises, osteopenia/bone fragility, extramedullary hematopoiesis, postsplenectomy sepsis, pulmonary hypertension, and leg ulcers were not uncommon. Overall, 87 (34%) of 254 patients had both a splenectomy and cholecystectomy. In those who had a splenectomy without simultaneous cholecystectomy, 48% later required a cholecystectomy. Although the risk of complications increases with severity of anemia and a genotype-phenotype relationship was observed, complications were common in all patients with PK deficiency. Diagnostic testing for PK deficiency should be considered in patients with apparent congenital hemolytic anemia and close monitoring for iron overload, gallstones, and other complications is needed regardless of baseline hemoglobin. This trial was registered at www.clinicaltrials.gov as #NCT02053480.
Asunto(s)
Anemia Hemolítica Congénita no Esferocítica/diagnóstico , Estudios de Asociación Genética , Piruvato Quinasa/deficiencia , Errores Innatos del Metabolismo del Piruvato/diagnóstico , Adolescente , Adulto , Anemia Hemolítica Congénita no Esferocítica/etiología , Anemia Hemolítica Congénita no Esferocítica/metabolismo , Anemia Hemolítica Congénita no Esferocítica/terapia , Transfusión Sanguínea , Niño , Preescolar , Colecistectomía/efectos adversos , Colecistectomía/métodos , Terapia Combinada , Activación Enzimática , Femenino , Genotipo , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Mutación , Fenotipo , Piruvato Quinasa/metabolismo , Errores Innatos del Metabolismo del Piruvato/etiología , Errores Innatos del Metabolismo del Piruvato/metabolismo , Errores Innatos del Metabolismo del Piruvato/terapia , Esplenectomía/efectos adversos , Esplenectomía/métodos , Evaluación de Síntomas , Resultado del Tratamiento , Adulto JovenRESUMEN
BACKGROUND: Extended half-life (EHL) factor VIII (FVIII) and IX (FIX) products are intended to decrease the burden of prophylaxis for patients with haemophilia A or B. Whether these newer concentrates have led to meaningful clinical practice change remains vague. AIM: To characterize the longitudinal use of standard (SHL) and EHL factor concentrates at haemophilia treatment centres (HTCs), using the ATHNdataset, a US database of 138 ATHN-affiliated HTCs. METHODS: Factor concentrate use among moderate and severe haemophilia A and B patients without inhibitors was analysed at three time points over 18 months. RESULTS: Use of EHL concentrates rose from 10% of patients to 22% during this study. EHL FVIII prophylaxis is prescribed to the minority of patients, 28%; EHL FIX now predominates for prophylaxis, 52%. Rates of prescribed EHL products varied significantly by age group and HTC region. Median prescribed prophylaxis for SHL compared to EHL products was FVIII 6240 and 5200 and FIX 6968 and FIX 3900 IU/kg/y, respectively. On-demand EHL use has grown but has minimal contribution to overall usage (2%). CONCLUSION: Haemophilia treatment centre region and patient age impact the rate of adoption of EHL products; however, EHL prescribing continues to rise nationally, particularly for EHL FIX. Careful attention to annual cost of prophylaxis is imperative as the decrease in median EHL prophylaxis consumption is not offset by the higher unit cost of these products. It is unclear how further growth in use of EHLs will be impacted by emerging non-factor replacement and gene therapies.
Asunto(s)
Costos y Análisis de Costo , Factor IX/economía , Factor IX/uso terapéutico , Factor VIII/economía , Factor VIII/uso terapéutico , Hemofilia A/tratamiento farmacológico , Hemofilia B/tratamiento farmacológico , Adolescente , Adulto , Factores de Edad , Niño , Prescripciones de Medicamentos/economía , Prescripciones de Medicamentos/estadística & datos numéricos , Factor IX/farmacocinética , Factor VIII/farmacocinética , Femenino , Geografía , Semivida , Hemofilia A/metabolismo , Hemofilia B/metabolismo , Humanos , Estudios Longitudinales , Masculino , Estados Unidos , Adulto JovenRESUMEN
Immune thrombocytopenia (ITP) is an autoimmune bleeding disorder with isolated thrombocytopenia and hemorrhagic risk. While many children with ITP can be safely observed, treatments are often needed for various reasons, including to decrease bleeding, or to improve health related quality of life (HRQoL). There are a number of available second-line treatments, including rituximab, thrombopoietin-receptor agonists, oral immunosuppressive agents, and splenectomy, but data comparing treatment outcomes are lacking. ICON1 is a prospective, multi-center, observational study of 120 children starting second-line treatments for ITP designed to compare treatment outcomes including platelet count, bleeding, and HRQoL utilizing the Kids ITP Tool (KIT). While all treatments resulted in increased platelet counts, romiplostim had the most pronounced effect at 6 months (P = .04). Only patients on romiplostim and rituximab had a significant reduction in both skin-related (84% to 48%, P = .01 and 81% to 43%, P = .004) and non-skin-related bleeding symptoms (58% to 14%, P = .0001 and 54% to 17%, P = .0006) after 1 month of treatment. HRQoL significantly improved on all treatments. However, only patients treated with eltrombopag had a median improvement in KIT scores at 1 month that met the minimal important difference (MID). Bleeding, platelet count, and HRQoL improved in each treatment group, but the extent and timing of the effect varied among treatments. These results are hypothesis generating and help to improve our understanding of the effect of each treatment on specific patient outcomes. Combined with future randomized trials, these findings will help clinicians select the optimal second-line treatment for an individual child with ITP.
Asunto(s)
Púrpura Trombocitopénica Idiopática , Calidad de Vida , Receptores Fc/administración & dosificación , Proteínas Recombinantes de Fusión/administración & dosificación , Rituximab/administración & dosificación , Trombopoyetina/administración & dosificación , Adolescente , Niño , Preescolar , Supervivencia sin Enfermedad , Femenino , Humanos , Lactante , Masculino , Recuento de Plaquetas , Estudios Prospectivos , Púrpura Trombocitopénica Idiopática/sangre , Púrpura Trombocitopénica Idiopática/tratamiento farmacológico , Tasa de Supervivencia , Factores de TiempoRESUMEN
Immune thrombocytopenia (ITP) is an acquired autoimmune bleeding disorder which presents with isolated thrombocytopenia and risk of hemorrhage. While most children with ITP promptly recover with or without drug therapy, ITP is persistent or chronic in others. When needed, how to select second-line therapies is not clear. ICON1, conducted within the Pediatric ITP Consortium of North America (ICON), is a prospective, observational, longitudinal cohort study of 120 children from 21 centers starting second-line treatments for ITP which examined treatment decisions. Treating physicians reported reasons for selecting therapies, ranking the top three. In a propensity weighted model, the most important factors were patient/parental preference (53%) and treatment-related factors: side effect profile (58%), long-term toxicity (54%), ease of administration (46%), possibility of remission (45%), and perceived efficacy (30%). Physician, health system, and clinical factors rarely influenced decision-making. Patient/parent preferences were selected as reasons more often in chronic ITP (85.7%) than in newly diagnosed (0%) or persistent ITP (14.3%, P = .003). Splenectomy and rituximab were chosen for the possibility of inducing long-term remission (P < .001). Oral agents, such as eltrombopag and immunosuppressants, were chosen for ease of administration and expected adherence (P < .001). Physicians chose rituximab in patients with lower expected adherence (P = .017). Treatment choice showed some physician and treatment center bias. This study illustrates the complexity and many factors involved in decision-making in selecting second-line ITP treatments, given the absence of comparative trials. It highlights shared decision-making and the need for well-conducted, comparative effectiveness studies to allow for informed discussion between patients and clinicians.
Asunto(s)
Toma de Decisiones Clínicas , Púrpura Trombocitopénica Idiopática/tratamiento farmacológico , Niño , Toma de Decisiones , Femenino , Humanos , Inmunosupresores/uso terapéutico , Masculino , Médicos/psicología , Rituximab/uso terapéutico , EsplenectomíaRESUMEN
Immune thrombocytopenia (ITP) patients with similarly low platelet counts differ in their tendency to bleed. To determine if differences in platelet function in ITP patients account for this variation in bleeding tendency, we conducted a single-center, cross-sectional study of pediatric patients with ITP. Bleeding severity (assessed by standardized bleeding score) and platelet function (assessed by whole blood flow cytometry) with and without agonist stimulation was evaluated in 57 ITP patients (median age, 9.9 years). After adjustment for platelet count, higher levels of thrombin receptor activating peptide (TRAP)-stimulated percent P-selectin- and activated glycoprotein (GP)IIb-IIIa-positive platelets were significantly associated with a lower bleeding score, whereas higher levels of immature platelet fraction (IPF), TRAP-stimulated platelet surface CD42b, unstimulated platelet surface P-selectin, and platelet forward light scatter (FSC) were associated with a higher bleeding score. Thus, platelet function tests related to platelet age (IPF, FSC) and activation through the protease activated receptor 1 (PAR1) thrombin receptor (TRAP-stimulated P-selectin, activated GPIIb-IIIa, and CD42b), independent of platelet count, are associated with concurrent bleeding severity in ITP. These tests may be useful markers of future bleeding risk in ITP.
Asunto(s)
Hemorragia/sangre , Hemorragia/etiología , Recuento de Plaquetas , Pruebas de Función Plaquetaria , Púrpura Trombocitopénica Idiopática/sangre , Púrpura Trombocitopénica Idiopática/complicaciones , Adolescente , Plaquetas/patología , Plaquetas/fisiología , Diferenciación Celular , Micropartículas Derivadas de Células/fisiología , Niño , Preescolar , Estudios Transversales , Femenino , Citometría de Flujo , Humanos , Luz , Masculino , Volúmen Plaquetario Medio , Selectina-P/sangre , Fragmentos de Péptidos/sangre , Complejo GPIIb-IIIa de Glicoproteína Plaquetaria/metabolismo , Complejo GPIb-IX de Glicoproteína Plaquetaria/metabolismo , Receptor PAR-1/sangre , Dispersión de RadiaciónRESUMEN
Our phase I, open-label, multi-center, dose-escalation study evaluated the pharmacokinetics (PK) of SP-420, a tridentate oral iron chelating agent of the desferrithiocin class, in patients with transfusion dependent ß-thalassemia. SP-420 was administered as a single dose of 1.5 (n = 3), 3 (n = 3), 6 (n = 3), 12 (n = 3), and 24 (n = 6) mg/kg or as a twice-daily dose of 9 mg/kg (n = 6) over 14-28 days. There was a near dose-linear increase in the mean plasma SP-420 concentrations and in the mean values for Cmax and AUC0-τ over the dose range evaluated. The median tmax ranged from 0.5 to 2.25 h and was not dose dependent. The study was prematurely terminated by the sponsor due to renal adverse events (AE) including proteinuria, increase in serum creatinine, and one case of Fanconi syndrome. Other adverse effects included hypersensitivity reactions and gastrointestinal disturbances. Based on current dose administration, the renal AE observed outweighed the possible benefits from chelation therapy. However, additional studies assessing efficacy and safety of lower doses or less frequent dosing of SP-420 over longer durations with close monitoring would be necessary to better explain the findings of our study and characterize the safety of the study drug.
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Ciclohexanonas/farmacocinética , Dihidropiridinas/efectos adversos , Quelantes del Hierro/efectos adversos , Quelantes del Hierro/farmacocinética , Tiazoles/efectos adversos , Tiazoles/farmacocinética , Talasemia beta/terapia , Adolescente , Adulto , Transfusión Sanguínea , Ciclohexanonas/efectos adversos , Ciclohexanonas/uso terapéutico , Dihidropiridinas/uso terapéutico , Relación Dosis-Respuesta a Droga , Humanos , Quelantes del Hierro/administración & dosificación , Enfermedades Renales/inducido químicamente , Persona de Mediana Edad , Sideróforos/uso terapéutico , Sideróforos/toxicidad , Tiazoles/uso terapéutico , Adulto Joven , Talasemia beta/complicaciones , Talasemia beta/tratamiento farmacológicoRESUMEN
An observational approach is recommended in newly diagnosed children with immune thrombocytopenia (ITP) at low risk of bleeding; however, there is no standard definition of risk. A standardized clinical assessment and management plan (SCAMP® ), a modifiable practice guideline, was implemented and revised (SCAMP-1 and SCAMP-2) and applied to 71 newly diagnosed patients with ITP. The Buchanan and Adix bleeding score guided treatment and was modified by stratifying by low- and high-risk grade 3 bleeding in SCAMP-2. Observation rates increased from 40% to 74% from SCAMP-1 to SCAMP-2 (P < 0.05) with no bleeding complications. We propose a modified bleeding score that increased observation rates in low-risk patients with ITP.
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Hemorragia/complicaciones , Planificación de Atención al Paciente , Púrpura Trombocitopénica Idiopática/diagnóstico , Púrpura Trombocitopénica Idiopática/terapia , Adolescente , Niño , Preescolar , Manejo de la Enfermedad , Femenino , Humanos , Lactante , Masculino , Resultado del TratamientoRESUMEN
Symptomatic ß-thalassemia is one of the globally most common inherited disorders. The initial clinical presentation is variable. Although common hematological analyses are typically sufficient to diagnose the disease, sometimes the diagnosis can be more challenging. We describe a series of patients with ß-thalassemia whose diagnosis was delayed, required bone marrow examination in one affected member of each family, and revealed ringed sideroblasts, highlighting the association of this morphological finding with these disorders. Thus, in the absence of characteristic congenital sideroblastic mutations or causes of acquired sideroblastic anemia, the presence of ringed sideroblasts should raise the suspicion of ß-thalassemia.
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Anemia Sideroblástica/patología , Células de la Médula Ósea/patología , Eritroblastos/patología , Talasemia beta/patología , Adolescente , Adulto , Anemia Sideroblástica/diagnóstico , Células de la Médula Ósea/citología , Examen de la Médula Ósea , Niño , Eritroblastos/citología , Eritrocitos Anormales , Femenino , Enfermedades Hematológicas/complicaciones , Humanos , Lactante , Masculino , Talasemia beta/diagnósticoRESUMEN
BACKGROUND: The relative safety and efficacy of recombinant activated coagulation factor VII (rFVIIa, NovoSeven® RT) across pediatric age cohorts is poorly defined. The objective of this analysis was to assess the safety and efficacy of rFVIIa in pediatric patients with congenital hemophilia with inhibitors (CHwI) in the clinical studies supporting the U.S. labeling. PROCEDURE: Pediatric data were derived from seven studies (five acute and two perioperative treatments) and pooled. All data were stratified by age (<2, 2 to <6, 6 to <12, and 12-16 years) and study category (acute treatment of bleeding episodes or surgery). RESULTS: The pediatric dataset included 172 patients; 144 received rFVIIa for the treatment of bleeding episodes and 28 for the control of bleeding perioperatively. Recombinant FVIIa was effective for 95.4% (1,026/1,076) of the evaluable bleeding episodes and had similar treatment effectiveness across pediatric age groups (range, 94.1-97.2%). The majority received doses of 90 mcg/kg. rFVIIa was effective in achieving perioperative hemostasis across pediatric age groups (range, 91-100%), with greater efficacy observed with the recommended (90 mcg/kg) versus lower dose (35 mcg/kg). A total of 88 pediatric patients experienced a total of 285 adverse drug reactions, similar in type to those reported among adult patients. A total of seven thrombotic events were recorded in seven pediatric patients; only one was confirmed related to rFVIIa upon individual case review. CONCLUSIONS: rFVIIa is safe and effective in the treatment of bleeding episodes and prevention of periprocedure bleeding in CHwI with no apparent differences observed among pediatric age groups.
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Ensayos de Uso Compasivo , Factor VIIa/uso terapéutico , Hemofilia A/tratamiento farmacológico , Adolescente , Niño , Preescolar , Factor VIIa/efectos adversos , Humanos , Lactante , Masculino , Proteínas Recombinantes/efectos adversos , Proteínas Recombinantes/uso terapéuticoRESUMEN
BACKGROUND: Patient transition readiness self-assessment tools and investigation into patient and parent perceptions of the transition process from pediatric to adult care models have informed recognition of gaps in care, particularly for those with chronic disease. Implementation of a longitudinal transition process with patient tracking provides the opportunity for individualized education and skill building and fosters a patient-centered model. PROCEDURE: Quality improvement intervention was used to assess and improve our transition process at annual comprehensive clinic visits for patients with bleeding disorders at our tertiary care pediatric center. RESULTS: Thirty-one patients with rare bleeding disorders received an introduction to the transition process using the HEMO-milestones tool in our hemophilia comprehensive clinic from September to December 2014. The percentage of patients with documented, age-specific hemophilia knowledge/skill assessment increased from 21% to 97%. The percentage of patients with documented skill building or adult care transfer plan increased from 55% to 93%. Designated postclinic team debriefings facilitated the creation of collaborative documentation summarizing each patient's transition readiness and plan for continued skill building. CONCLUSIONS: The HEMO-milestones tool promotes a standardized approach to evaluation of self-management competency. When combined with a collaborative multidisciplinary effort, it increases plans for skill building in patients with hemophilia. This tool is easily modifiable for alternate subspecialty use and does not require extensive training for implementation.