An update on the US adult thalassaemia population: a report from the CDC thalassaemia treatment centres.

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.

Epidemiologic and clinical characteristics of nontransfusion-dependent thalassemia in the United States.

BACKGROUND: Nontransfusion-dependent thalassemia (NTDT) refers to a diverse group of thalassemia mutations and clinical phenotypes that do not require chronic transfusions. It is increasingly prevalent in the United States. PROCEDURE: This study reviews the epidemiology and clinical characteristics of 138 patients with NTDT treated at four US thalassemia centers from 1997 to 2014. Data on laboratory results, transfusions, and clinical complications were collected from patient charts. RESULTS: Overall, 84 patients with α-thalassemia (62 deletional hemoglobin H; 22 nondeletional hemoglobin H), 39 with ß-thalassemia (26 with homozygous or double heterozygous ß mutations; 13 with single ß mutations with or without α triplication), and 15 with E/ß-thalassemia (12 E/ß0 ; three E/ß+ ) were identified. At study entry, the median age for patients with α-thalassemia was 2.3 years; 9.2 years for patients with ß-thalassemia and 2.2 years for patients with E/ß-thalassemia. Most patients with α-thalassemia were Asian. Patients with ß-thalassemia were predominantly Caucasian (46%) or of African descent (36%). Twenty percent of patients were born outside the United States and 5% were transfused before immigration. Complications varied by genotype and age. Individuals with nondeletional hemoglobin H were severely affected and, despite their young age, had many complications. Iron overload increased with age and was more common in patients who received transfusions. CONCLUSIONS: NTDT in the United States is a multi-ethnic disease with different genotypic mutations and phenotypic manifestations. A higher than expected proportion of patients was Black/African American. NTDT-related complications are common and increase with age, supporting a need for early diagnosis.

Safety and pharmacokinetics of the oral iron chelator SP-420 in ß-thalassemia.

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.

Safe mobilization of CD34+ cells in adults with ß-thalassemia and validation of effective globin gene transfer for clinical investigation.

We conducted a pilot trial to investigate the safety and effectiveness of mobilizing CD34(+) hematopoietic progenitor cells (HPCs) in adults with ß-thalassemia major. We further assessed whether thalassemia patient CD34(+) HPCs could be transduced with a globin lentiviral vector under clinical conditions at levels sufficient for therapeutic implementation. All patients tolerated granulocyte colony-stimulating factor well with minimal side effects. All cell collections exceeded 8 × 10(6) CD34(+) cells/kg. Using clinical grade TNS9.3.55 vector, we demonstrated globin gene transfer averaging 0.53 in 3 validation runs performed under current good manufacturing practice conditions. Normalized to vector copy, the vector-encoded ß-chain was expressed at a level approximating normal hemizygous protein output. Importantly, stable vector copy number (0.2-0.6) and undiminished vector expression were obtained in NSG mice 6 months posttransplant. Thus, we validated a safe and effective procedure for ß-globin gene transfer in thalassemia patient CD34(+) HPCs, which we will implement in the first US trial in patients with severe inherited globin disorders. This trial is registered at www.clinicaltrials.gov as #NCT01639690.

Mutations in TRNT1 cause congenital sideroblastic anemia with immunodeficiency, fevers, and developmental delay (SIFD).

Mutations in genes encoding proteins that are involved in mitochondrial heme synthesis, iron-sulfur cluster biogenesis, and mitochondrial protein synthesis have previously been implicated in the pathogenesis of the congenital sideroblastic anemias (CSAs). We recently described a syndromic form of CSA associated with B-cell immunodeficiency, periodic fevers, and developmental delay (SIFD). Here we demonstrate that SIFD is caused by biallelic mutations in TRNT1, the gene encoding the CCA-adding enzyme essential for maturation of both nuclear and mitochondrial transfer RNAs. Using budding yeast lacking the TRNT1 homolog, CCA1, we confirm that the patient-associated TRNT1 mutations result in partial loss of function of TRNT1 and lead to metabolic defects in both the mitochondria and cytosol, which can account for the phenotypic pleiotropy.

A novel syndrome of congenital sideroblastic anemia, B-cell immunodeficiency, periodic fevers, and developmental delay (SIFD).

Congenital sideroblastic anemias (CSAs) are a heterogeneous group of inherited disorders identified by pathological erythroid precursors with perinuclear mitochondrial iron deposition in bone marrow. An international collaborative group of physicians and laboratory scientists collated clinical information on cases of CSA lacking known causative mutations, identifying a clinical subgroup of CSA associated with B immunodeficiency, periodic fevers, and development delay. Twelve cases from 10 families were identified. Median age at presentation was 2 months. Anemia at diagnosis was sideroblastic, typically severe (median hemoglobin, 7.1 g/dL) and markedly microcytic (median mean corpuscular volume, 62.0 fL). Clinical course involved recurrent febrile illness and gastrointestinal disturbance, lacking an infective cause. Investigation revealed B-cell lymphopenia (CD19⁺ range, 0.016-0.22 × 109/L) and panhypogammaglobulinemia in most cases. Children displayed developmental delay alongside variable neurodegeneration, seizures, cerebellar abnormalities, sensorineural deafness, and other multisystem features. Most required regular blood transfusion, iron chelation, and intravenous immunoglobulin replacement. Median survival was 48 months, with 7 deaths caused by cardiac or multiorgan failure. One child underwent bone marrow transplantation aged 9 months, with apparent cure of the hematologic and immunologic manifestations. We describe and define a novel CSA and B-cell immunodeficiency syndrome with additional features resembling a mitochondrial cytopathy. The molecular etiology is under investigation.

Chelation use and iron burden in North American and British thalassemia patients: a report from the Thalassemia Longitudinal Cohort.

Morbidity and mortality in thalassemia are associated with iron burden. Recent advances in organ-specific iron imaging and the availability of oral deferasirox are expected to improve clinical care, but the extent of use of these resources and current chelation practices have not been well described. In the present study, we studied chelation use and the change in iron measurements in 327 subjects with transfusion-dependent thalassemia (mean entry age, 22.1 ± 2.5 years) from 2002-2011, with a mean follow-up of 8.0 years (range, 4.4-9.0 years). The predominant chelator currently used is deferasirox, followed by deferoxamine and then combination therapies. The use of both hepatic and cardiac magnetic resonance imaging increased more than 5-fold (P < .001) during the study period, leading to an 80% increase in the number of subjects undergoing liver iron concentration (LIC) measurements. Overall, LIC significantly improved (median, 10.7 to 5.1 mg/g dry weight, P < .001) with a nonsignificant improvement in cardiac T2* (median, 23.55 to 34.50 ms, P = .23). The percentage of patients with markers of inadequate chelation (ferritin > 2500 ng/mL, LIC > 15 mg/g dry weight, and/or cardiac T2* < 10 ms) also declined from 33% to 26%. In summary, increasing use of magnetic resonance imaging and oral chelation in thalassemia management has likely contributed to improved iron burden.

Red blood cell transfusions for thalassemia: results of a survey assessing current practice and proposal of evidence-based guidelines.

BACKGROUND: In the absence of curative treatment, such as stem cell transplant, regular transfusions remain the mainstay of therapy for individuals with thalassemia major, a syndrome that results from marked ineffective erythropoiesis and the resultant anemia. The primary objectives of transfusion therapy are twofold: to suppress ineffective erythropoiesis and to ensure appropriate growth and development through childhood. In practice, a number of different transfusion protocols are in use across the developed world, with on-demand transfusion still being the paradigm in most of the developing world with limited resources. STUDY DESIGN AND METHODS: To investigate perceived differences in transfusion practice, a self-reported electronic survey was disseminated to eight US thalassemia treatment centers in February 2011. The survey was divided into sections ranging from laboratory and clinical practices to emerging transfusion-transmitted diseases. RESULTS: The survey response rate was 100%. The total number of transfused patients was 411. One-hundred percent of institutions used leukoreduced blood. No centers routinely provided cytomegalovirus-seronegative red blood cells (RBCs). Half the centers provided irradiated RBCs; only one routinely provided washed RBCs, and none transfused RBCs of defined storage age. Seventy-five percent of centers routinely phenotyped thalassemia patients' RBC antigens; 50% prophylactically matched for Rh and K antigens. The frequency of antibody investigations varied widely, and 25% of centers routinely medicated patients before transfusion. CONCLUSION: Eight thalassemia centers in the United States were surveyed to determine the uniformity of transfusion practice. The variability of the results was surprising. Consequently, we performed a literature review and propose an evidence-based protocol for routine transfusion therapy for patients with thalassemia.

Transfusion complications in thalassemia patients: a report from the Centers for Disease Control and Prevention (CME).

BACKGROUND: Transfusions are the primary therapy for thalassemia but have significant cumulative risks. In 2004, the Centers for Disease Control and Prevention (CDC) established a national blood safety monitoring program for thalassemia. This report summarizes the population and their previous nonimmune and immune transfusion complications. STUDY DESIGN AND METHODS: The CDC Thalassemia Blood Safety Network is a consortium of centers longitudinally following patients. Enrollment occurred from 2004 through 2012. Demographics, transfusion history, infectious exposures, and transfusion and nontransfusion complications were summarized. Logistic regression analyses of factors associated with allo- and autoimmunization were employed. RESULTS: The race/ethnicity of these 407 thalassemia patients was predominantly Asian or Caucasian. The mean ± SD age was 22.3 ± 13.2 years and patients had received a mean ± SD total number of 149 ± 103.4 units of red blood cells (RBCs). Multiorgan dysfunction was common despite chelation. Twenty-four percent of transfused patients had previous exposure to possible transfusion-associated pathogens including one case of babesia. As 27% were immigrants, the infection source cannot be unequivocally linked to transfusion. Transfusion reactions occurred in 48%, including allergic, febrile, and hemolytic; 19% were alloimmunized. Common antigens were E, Kell, and C. Years of transfusion was the strongest predictor of alloimmunization. Autoantibodies occurred in 6.5% and were associated with alloimmunization (p < 0.0001). Local institutional policies, not patient characteristics, were major determinants of blood preparation and transfusion practices. CONCLUSION: Hemosiderosis, transfusion reactions, and infections continue to be major problems in thalassemia. New pathogens were noted. National guidelines for RBC phenotyping and preparation are needed to decrease transfusion-related morbidity.

Negative affect differentiation and adherence during treatment for thalassemia.

BACKGROUND: Although research has demonstrated the detrimental effects of excessive negative affect on treatment adherence and morbidity in chronic illness, rarely have researchers investigated the benefits of awareness of negative emotional experiences during treatment. PURPOSE: In this investigation, we examined the association of negative affect differentiation (the ability to report negative emotional experiences as separate and distinct from each other,) to treatment adherence in adult patients with the congenital blood disorder thalassemia. METHOD: Negative affect differentiation was assessed during a 12-16-week treatment-based diary and adherence was operationalized as attendance at routine screenings over 12 months. Participants were adult patients (n = 32; age M = 31.63, SD = 7.72; 72 % female) with transfusion-dependent thalassemia in treatment in a large metropolitan hospital in the Northeastern USA. RESULTS: The results indicate that negative affect differentiation is significantly associated with greater adherence to treatment, even when controlling for disease burden and level of psychological distress. CONCLUSION: Although preliminary, this investigation suggests that differentiated processing of negative emotional experiences during illness can lead to adaptive treatment-related behavior. As such, it may present a new avenue for research and intervention targeting the improvement of adherence during treatment for chronic illness.

Increased leucocyte apoptosis in transfused ß-thalassaemia patients.

This exploratory study assessed apoptosis in peripheral blood leucocytes (PBL) from ß-thalassaemia patients receiving chronic transfusions and chelation therapy (deferasirox or deferoxamine) at baseline, 1, 6, and 12 months. At baseline, thalassaemic PBLs presented 50% greater levels of Bax (BAX), 75% higher caspase-3/7, 48% higher caspase-8 and 88% higher caspase-9 activities and 428% more nucleosomal DNA fragmentation than control subjects. Only neutrophils correlated significantly with apoptotic markers. Previously, we showed that over the treatment year, hepatic iron declined; we now show that the ratio of Bax/Bcl-2 (BCL2), (-27·3%/year), and caspase-9 activity (-13·3%/year) declined in both treatment groups, suggesting that chelation decreases body iron and indicators of PBL apoptosis.

How I treat thalassemia.

The purpose of this article is to set forth our approach to diagnosing and managing the thalassemias, including ß-thalassemia intermedia and ß-thalassemia major. The article begins by briefly describing recent advances in our understanding of the pathophysiology of thalassemia. In the discussion on diagnosing the condition, we cover the development of improved diagnostic tools, including the use of very small fetal DNA samples to detect single point mutations with great reliability for prenatal diagnosis of homozygous thalassemia. In our description of treatment strategies, we focus on how we deal with clinical manifestations and long-term complications using the most effective current treatment methods for ß-thalassemia. The discussion of disease management focuses on our use of transfusion therapy and the newly developed oral iron chelators, deferiprone and deferasirox. We also deal with splenectomy and how we manage endocrinopathies and cardiac complications. In addition, we describe our use of hematopoietic stem cell transplantation, which has produced cure rates as high as 97%, and the use of cord blood transplantation. Finally, we briefly touch on therapies that might be effective in the near future, including new fetal hemoglobin inducers and gene therapy.

Risk factors and mortality associated with an elevated tricuspid regurgitant jet velocity measured by Doppler-echocardiography in thalassemia: a Thalassemia Clinical Research Network report.

An elevated tricuspid regurgitant jet velocity (TRV) is associated with hemolysis and early mortality in sickle cell disease, yet risk factors, clinical parameters, and mortality associated with this biomarker in thalassemia are poorly defined. This report summarizes the prevalence of an elevated TRV in 325 patients screened by Doppler echocardiography in the Thalassemia Clinical Research Network. A documented TRV was reported in 148 of 325 (46%) of patients. Average age was 25.9 years (range, 5-56 years) and 97% were transfusion-dependent. Mean TRV was 2.3 ± 0.4 m/s (range, 0.2-3.5 m/s). An abnormal TRV ≥ 2.5 m/s was identified in 49 of 148 (33%) of patients with a documented TRV, 5% (8/148), with a TRV ≥ 3.0 m/s, suggesting significant PH risk. Older age was strongly associated with a high TRV; however, 16% of children had a TRV ≥ 2.5 m/s. A history of splenectomy, hepatitis C, smoking, or high white blood cell count was associated with TRV elevation. In summary, an elevated TRV is noted in one-third of transfusion-dependent thalassemia patients with a documented value and develops in both children and adults. Age, splenectomy, hepatitis C, and smoking are significant univariate risk factors, with splenectomy surfacing as the dominant risk factor over time. Mortality was low in this cohort. Prospective longitudinal studies are needed. This study is registered at http://www.clinicaltrials.gov as NCT00661804.

Toward optimizing the use of deferasirox: potential benefits of combined use with deferoxamine.

Patients with ß-thalassemia require iron chelation therapy to protect against progressive iron overload and non-transferrin-bound iron. Some patients fail to respond adequately to deferoxamine and deferasirox monotherapy while others have side effects which limit their use of these drugs. Since combining deferiprone and deferoxamine has an additive effect, placing all patients into net negative iron balance, we investigated the possibility that combining deferasirox and deferoxamine would lead to similar results. We conducted 34-day metabolic iron balance studies in six patients in whom the relative effectiveness of deferasirox (30 mg/kg/day) and deferoxamine (40 mg/kg/day) was compared, alone and in combination. Patients consumed fixed low-iron diets; daily urinary and stool iron excretion were determined by atomic absorption. Red blood cell transfusions were given prior to each drug treatment to minimize the effects of ineffective erythropoiesis. Serial safety measures, hematologic parameters, serum chemistries, ferritin levels and urinalyses were determined. All patients were in negative iron balance when treated with deferoxamine alone while four of six patients remained in positive balance when deferasirox monotherapy was evaluated. Daily use of both drugs had a synergistic effect in two patients and an additive effect in three others. Five of six patients would be in negative iron balance if they used the combination of drugs just 3 days a week. No significant or drug-related changes were observed in the blood work-ups or urinalyses performed. We conclude that supplementing the daily use of deferasirox with 2 - 3 days of deferoxamine therapy would place all patients into net negative iron balance thereby providing a convenient way to tailor chelation therapy to the individual needs of each patient.

Longitudinal monitoring of cardiac siderosis using cardiovascular magnetic resonance T2* in patients with thalassemia major on various chelation regimens: a 6-year study.

Cardiovascular magnetic resonance (CMR) and hepatic magnetic resonance imaging (MRI) have become reliable noninvasive tools to monitor iron excess in thalassemia major (TM) patients. However, long-term studies are lacking. We reviewed CMR and hepatic MRI T2* imaging on 54 TM patients who had three or more annual measurements. They were managed on various chelation regimens. Patients were grouped according to their degree of cardiac siderosis: severe (T2*, <10 msec), mild to moderate (T2* = 10-20 msec), and no cardiac siderosis (T2*, >20 msec). We looked at the change in cardiac T2*, liver iron concentration (LIC) and left ventricular ejection fraction (LVEF) at years 3 and 5. In patients with severe cardiac siderosis, cardiac T2* (mean ± SD) improved from 6.9 ± 1.6 at baseline to 13.6 ± 10.0 by year 5, mean ΔT2* = 6.7 (P = 0.04). Change in cardiac T2* at year 3 was not significant in the severe group. Patients with mild to moderate cardiac siderosis had mean cardiac T2* of 14.6 ± 2.9 at baseline which improved to 26.3 ± 9.5 by year 3, mean ΔT2* = 1.7 (P = 0.01). At baseline, median LICs (mg/g dry weight) in patients with severe, mild-moderate, and no cardiac siderosis were 3.6, 2.8, and 3.3, whereas LVEFs (mean ± SD) (%) were 56.3 ± 10.1, 60 ± 5, and 66 ± 7.6, respectively. No significant correlation was noted between Δ cardiac T2* and Δ LIC, Δ cardiac T2*, and Δ LVEF at years 3 and 5. Throughout the observation period, patients with no cardiac siderosis maintained their cardiac T2* above 20 msec. The majority of patients with cardiac siderosis improve cardiac T2* over time with optimal chelation.

Pregnancy outcomes in women with thalassemia in North America and the United Kingdom.

Improved survival in thalassemia has refocused attention on quality of life, including family planning. Understanding the issues associated with infertility and adverse pregnancy outcomes may impact clinical care of patients with thalassemia. We report the number and outcomes of pregnancies among subjects enrolled in Thalassemia Clinical Research Network (TCRN) registries and examine variables associated with successful childbirth. We identified 129 pregnancies in 72 women among the 264 women, age 18 years or older in our dataset. Over 70% of pregnancies resulted in live births and 73/83 (88%) of live births occurred at full term. Most pregnancies (78.2%) were conceived without reproductive technologies. Most (59.3%) pregnancies occurred while on chronic transfusion programs, however only 38.9% were on iron chelation. Four women developed heart problems. Iron burden in women who had conceived was not significantly different from age- and diagnosis-matched controls that had never been pregnant. There was also no difference in pregnancy outcomes associated with diagnosis, transfusion status, diabetes or Hepatitis C infection. Pregnancies occurred in 27.3% of women with thalassemia of child-bearing age in the TCRN registries, a notable increase from our previous 2004 report. With optimal health maintenance, successful pregnancies may be achievable.

Treatment of heart failure in adults with thalassemia major: response in patients randomised to deferoxamine with or without deferiprone.

BACKGROUND: Established heart failure in thalassaemia major has a poor prognosis and optimal management remains unclear. METHODS: A 1 year prospective study comparing deferoxamine (DFO) monotherapy or when combined with deferiprone (DFP) for patients with left ventricular ejection fraction (LVEF) <56% was conducted by the Thalassemia Clinical Research Network (TCRN). All patients received DFO at 50-60 mg/kg 12-24 hr/day sc or iv 7 times weekly, combined with either DFP 75 at mg/kg/day (combination arm) or placebo (DFO monotherapy arm). The primary endpoint was the change in LVEF by CMR. RESULTS: Improvement in LVEF was significant in both study arms at 6 and 12 months (p = 0.04), normalizing ventricular function in 9/16 evaluable patients. With combination therapy, the LVEF increased from 49.9% to 55.2% (+5.3% p = 0.04; n = 10) at 6 months and to 58.3% at 12 months (+8.4% p = 0.04; n = 7). With DFO monotherapy, the LVEF increased from 52.8% to 55.7% (+2.9% p = 0.04; n = 6) at 6 months and to 56.9% at 12 months (+4.1% p = 0.04; n = 4). The LVEF trend did not reach statistical difference between study arms (p = 0.89). In 2 patients on DFO monotherapy during the study and in 1 patient on combined therapy during follow up, heart failure deteriorated fatally. The study was originally powered for 86 participants to determine a 5% difference in LVEF improvement between treatments. The study was prematurely terminated due to slow recruitment and with the achieved sample size of 20 patients there was 80% power to detect an 8.6% difference in EF, which was not demonstrated. Myocardial T2* improved in both arms (combination +1.9 ± 1.6 ms p = 0.04; and DFO monotherapy +1.9 ± 1.4 ms p = 0.04), but with no significant difference between treatments (p = 0.65). Liver iron (p = 0.03) and ferritin (p < 0.001) both decreased significantly in only the combination group. CONCLUSIONS: Both treatments significantly improved LVEF and myocardial T2*. Although this is the largest and only randomized study in patients with LV decompensation, further prospective evaluation is needed to identify optimal chelation management in these high-risk patients.

The palatability and tolerability of deferasirox taken with different beverages or foods.

BACKGROUND: Deferasirox is a once-daily, oral iron chelator that was developed out of a need for a long-acting, conveniently-administered chelator for patients with transfusional hemosiderosis. The approved mode of administration requires taking deferasirox on an empty stomach with water, apple juice, or orange juice to limit variation in bioavailability. This required administration schedule might not be palatable for patients. Additionally, approximately one-quarter of patients experience mild to moderate gastrointestinal (GI) symptoms, which may pose additional challenges, particularly in the younger and older age ranges. We present a trial to assess the palatability and safety of various administration modes of deferasirox in pediatric and adult patients. PROCEDURES: Participants rated palatability in a 4-week run-in phase, where deferasirox was administered per label. Subsequently, patients rated several administration modes during a 3-month assessment phase. RESULTS: Palatability was more favorable during the assessment phase, with 47% of patient ratings for palatability being favorable while only 38% were favorable during the run-in phase. The most highly rated choice was deferasirox taken with a soft food at breakfast. In addition, there was an indication of improved GI tolerability during the assessment phase (symptoms were reported in 37% of patients during run-in and 32% during the assessment phase; rates of diarrhea decreased significantly). Although trough PK values increased, no major new toxicities were observed. CONCLUSIONS: These data indicate that different administration options may improve palatability and GI tolerability, which could have a positive impact on treatment adherence. (ClinicalTrials.gov number, NCT00845871)

Parental and other factors associated with hydroxyurea use for pediatric sickle cell disease.

BACKGROUND: Hydroxyurea (HU) is highly effective treatment for sickle cell disease (SCD). While pediatric use of HU is accepted clinical practice, barriers to use may impede its potential benefit. PROCEDURE: A survey of parents of children ages 5-17 years with SCD was performed across five institutions to assess factors associated with HU use. RESULTS: Of the 173 parent responses, 65 (38%) had children currently taking HU. Among parents of children not taking HU, the most commonly cited reasons were that their hematology provider had not offered it, their child was not sufficiently symptomatic and concerns about potential side effects. Even parents of HU users reported widespread concern about effectiveness, long-term safety, and off-label use. In bivariate analyses, children's ages, parental demographics such as education level, or travel time to their hematology provider were not correlated with HU use. Bivariate analysis and multivariate logistic regression revealed three significant factors associated with current HU use: better parental knowledge about its major therapeutic effects (P < 0.001), sickle genotype (P = 0.005), and institution of clinical care (P = 0.04). CONCLUSIONS: Pervasive concerns about HU safety exist, even among parents of current users. Varying knowledge among parents appears to be independent of their demographics, and is associated with HU use. Inter-institutional variability in parental knowledge and drug uptake highlights potentially potent site-specific influences on likelihood of HU use. Overall, these survey data underscore the need for strategies to bolster parental understanding about benefits of HU and address concerns about its safety.

The effect of deferasirox on cardiac iron in thalassemia major: impact of total body iron stores.

We present results from a prospective, multicenter, open-label, single-arm study evaluating response of cardiac and liver iron to deferasirox therapy for 18 months. Twenty-eight patients with abnormal T2* and normal left ventricular ejection fraction were enrolled from 4 US centers. All patients initially received deferasirox doses of 30 to 40 mg/kg per day. Patients were severely iron overloaded: mean liver iron concentration (LIC) 20.3 mg Fe/g dry weight, serum ferritin 4417 ng/mL, and cardiac T2* 8.6 ms. In the intent-to-treat population, 48% reached the primary endpoint (cardiac T2* improvement at 18 months, P = not significant). There were 2 deaths: 1 from congestive heart failure and 1 from sepsis. In the 22 patients completing the trial, LIC and cardiac T2* improvements were 16% (P = .06) and 14% (P = .07), respectively. Cardiac T2* improvement (13 patients) was predicted by initial LIC, final LIC, and percentage LIC change, but not initial cardiac T2*. Cardiac iron improved 24% in patients having LIC in the lower 2 quartiles and worsened 8.7% in patients having LIC in the upper 2 quartiles. Left ventricular ejection fraction was unchanged at all time points. Monotherapy with deferasirox was effective in patients with mild to moderate iron stores but failed to remove cardiac iron in patients with severe hepatic iron burdens. This study was registered at www.clinicaltrials.gov as #NCT00447694.