Beatrice Files

Hydroxycarbamide in very young children with sickle-cell anaemia: a multicentre, randomised, controlled trial (BABY HUG)

BACKGROUND Sickle-cell anaemia is associated with substantial morbidity from acute complications and organ dysfunction beginning in the first year of life. Hydroxycarbamide substantially reduces episodes of pain and acute chest syndrome, admissions to hospital, and transfusions in adults with sickle-cell anaemia. We assessed the effect of hydroxycarbamide therapy on organ dysfunction and clinical complications, and examined laboratory findings and toxic effects. METHODS This randomised trial was undertaken in 13 centres in the USA between October, 2003, and September, 2009. Eligible participants had haemoglobin SS (HbSS) or haemoglobin Sβ(0)thalassaemia, were aged 9-18 months at randomisation, and were not selected for clinical severity. Participants received liquid hydroxycarbamide, 20 mg/kg per day, or placebo for 2 years. Randomisation assignments were generated by the medical coordinating centre by a pre-decided schedule. Identical appearing and tasting formulations were used for hydroxycarbamide and placebo. Patients, caregivers, and coordinating centre staff were masked to treatment allocation. Primary study endpoints were splenic function (qualitative uptake on (99)Tc spleen scan) and renal function (glomerular filtration rate by (99m)Tc-DTPA clearance). Additional assessments included blood counts, fetal haemoglobin concentration, chemistry profiles, spleen function biomarkers, urine osmolality, neurodevelopment, transcranial Doppler ultrasonography, growth, and mutagenicity. Study visits occurred every 2-4 weeks. Analysis was by intention to treat. The trial is registered with ClinicalTrials.gov, number NCT00006400. FINDINGS 96 patients received hydroxycarbamide and 97 placebo, of whom 83 patients in the hydroxycarbamide group and 84 in the placebo group completed the study. Significant differences were not seen between groups for the primary endpoints (19 of 70 patients with decreased spleen function at exit in the hydroxycarbamide group vs 28 of 74 patients in the placebo group, p=0·21; and a difference in the mean increase in DTPA glomerular filtration rate in the hydroxycarbamide group versus the placebo group of 2 mL/min per 1·73 m(2), p=0·84). Hydroxycarbamide significantly decreased pain (177 events in 62 patients vs 375 events in 75 patients in the placebo group, p=0·002) and dactylitis (24 events in 14 patients vs 123 events in 42 patients in the placebo group, p<0·0001), with some evidence for decreased acute chest syndrome, hospitalisation rates, and transfusion. Hydroxyurea increased haemoglobin and fetal haemoglobin, and decreased white blood-cell count. Toxicity was limited to mild-to-moderate neutropenia. INTERPRETATION On the basis of the safety and efficacy data from this trial, hydroxycarbamide can now be considered for all very young children with sickle-cell anaemia. FUNDING The US National Heart, Lung, and Blood Institute; and the National Institute of Child Health and Human Development.

A randomised comparison of deferasirox versus deferoxamine for the treatment of transfusional iron overload in sickle cell disease

Deferasirox is a once‐daily, oral iron chelator developed for treating transfusional iron overload. Preclinical studies indicated that the kidney was a potential target organ of toxicity. As patients with sickle cell disease often have abnormal baseline renal function, the primary objective of this randomised, open‐label, phase II trial was to evaluate the safety and tolerability of deferasirox in comparison with deferoxamine in this population. Assessment of efficacy, as measured by change in liver iron concentration (LIC) using biosusceptometry, was a secondary objective. A total of 195 adult and paediatric patients received deferasirox (n = 132) or deferoxamine (n = 63). Adverse events most commonly associated with deferasirox were mild, including transient nausea, vomiting, diarrhoea, abdominal pain and skin rash. Abnormal laboratory studies with deferasirox were occasionally associated with mild non‐progressive increases in serum creatinine and reversible elevations in liver function tests. Discontinuation rates from deferasirox (11·4%) and deferoxamine (11·1%) were similar. Over 1 year, similar dose‐dependent LIC reductions were observed with deferasirox and deferoxamine. Once‐daily oral deferasirox has acceptable tolerability and appears to have similar efficacy to deferoxamine in reducing iron burden in transfused patients with sickle cell disease.

Stroke Prevention Trial in Sickle Cell Anemia

Stroke occurs in 7-8% of children with Sickle Cell Disease (Hb SS) and is a major cause of morbidity. Rates of recurrence have been reduced from 46-90% to less than 10% through chronic blood transfusions. Prevention of first stroke, however, would be preferable because even one stroke can cause irreversible brain injury. Transcranial Doppler (TCD) ultrasound can detect arterial blood flow rates associated with subsequent stroke risk. By combining TCD screening and a potentially effective treatment, first stroke may be prevented. The Stroke Prevention Trial in Sickle Cell Anemia (STOP) is the first stroke prevention trial in Hb SS and the first randomized, controlled use of transfusion in Hb SS. This multi-center trial is designed to test whether reducing sickle hemoglobin to 30% or less with periodic blood transfusions will reduce first-time stroke by at least 70% compared to standard care. Primary endpoints will be clinically evident symptoms of cerebral infarction with consistent findings on Magnetic Resonance Imaging and Angiography (MRI/MRA) or symptomatic intracranial hemorrhage. Secondary endpoints will be asymptomatic brain lesions detected by MRI in brain areas not involved in primary endpoints. The design calls for a 6-month start-up interval, 18 months of TCD screening and randomization, and observation for stroke from entry through month 54. Key features of the trial are standardized TCD and MRI/MRA protocols interpreted blindly, and blinded adjudication of endpoints. The sample size (60 per treatment group) is based on prospective data relating TCD velocity to risk of stroke. A time-averaged mean velocity of > or = 200 cm/sec is associated with a 46% risk of cerebral infarction over 39 months. The sample size is sufficient to detect 70% reduction in the primary endpoint at 90% power. This trial will determine if transfusion is effective in the primary prevention of stroke. Secondary aims may further the understanding of the effects of transfusion on the brain and guide future research into cerebrovascular disease in Hb SS.

Impact of hydroxyurea on clinical events in the BABY HUG trial

The Pediatric Hydroxyurea Phase 3 Clinical Trial (BABY HUG) was a phase 3 multicenter, randomized, double-blind, placebo-controlled clinical trial of hydroxyurea in infants (beginning at 9-18 months of age) with sickle cell anemia. An important secondary objective of this study was to compare clinical events between the hydroxyurea and placebo groups. One hundred and ninety-three subjects were randomized to hydroxyurea (20 mg/kg/d) or placebo; there were 374 patient-years of on-study observation. Hydroxyurea was associated with statistically significantly lower rates of initial and recurrent episodes of pain, dactylitis, acute chest syndrome, and hospitalization; even infants who were asymptomatic at enrollment had less dactylitis as well as fewer hospitalizations and transfusions if treated with hydroxyurea. Despite expected mild myelosuppression, hydroxyurea was not associated with an increased risk of bacteremia or serious infection. These data provide important safety and efficacy information for clinicians considering hydroxyurea therapy for very young children with sickle cell anemia. This clinical trial is registered with the National Institutes of Health (NCT00006400, www.clinicaltrials.gov).

Patient-Reported Outcomes of Deferasirox (Exjade®, ICL670) versus Deferoxamine in Sickle Cell Disease Patients with Transfusional Hemosiderosis

Background/Aims: There is increasing evidence demonstrating the value of transfusions in sickle cell disease (SCD). However, resultant iron overload can be life threatening if untreated. Chelation therapy with deferoxamine requires parenteral infusions that can negatively impact quality of life and adherence to treatment. Methods: As part of a phase II trial, SCD patient-reported outcomes were evaluated. One hundred and ninety-five patients were randomized (2:1) to receive oral deferasirox (5–30 mg/kg/day) or deferoxamine (20–50 mg/kg, 5 days per week); 121 had previously received deferoxamine. Results: At each time point, significantly more patients who had previously received deferoxamine were ‘satisfied/very satisfied’ with deferasirox, or found treatment to be ‘convenient/very convenient’ compared with deferoxamine (p < 0.001). In these patients, fewer hours were lost from daily activities with deferasirox than deferoxamine treatment. Most patients (77%) preferred deferasirox, and more were willing to continue taking deferasirox than deferoxamine at end-of-study (84 vs. 11%, respectively). Conclusions: Patients with SCD are therefore more satisfied with deferasirox, which has a lower impact on daily activities than deferoxamine. Given the high levels of satisfaction, it is likely that quality of life will be improved. These results also suggest that treatment adherence with deferasirox may be better than with deferoxamine, which should lead to improved long-term outcomes.

Longitudinal changes in ferritin during chronic transfusion: a report from the Stroke Prevention Trial in Sickle Cell Anemia (STOP).

Purpose Chronic red cell transfusion has been used for prevention of recurrent stroke in patients with sickle cell disease for three decades, and its effectiveness in primary prevention was recently shown. Iron overload, the inevitable result of chronic transfusion, is commonly monitored with serum ferritin concentration. Patients and Methods Sixty-one patients at high risk for stroke received chronic transfusion in a clinical trial of stroke prevention. A serum ferritin level of less than 500 ng/mL was required for study entry. Ferritin levels were obtained quarterly. Fifty patients who had four or more ferritin measurements were included in this analysis. Transfusions were administered as exchange or simple, with washed, reconstituted, or packed red blood cells, at the discretion of the site investigator. Results Serum ferritin levels increased linearly with cumulative transfusion volume during the first four ferritin measurements, but the rate of increase varied widely among patients. Rates of increase varied similarly among 23 patients who received exclusively simple transfusion with packed red cells and in five patients who received exchange transfusions. Thirty-two patients received a total transfusion volume of more than 250 mL/kg. Ferritin continued to increase linearly after the first four measurements in 14, but the remaining 18 experienced a plateau before the level reached 3,000 ng/mL. Six of those with a linear increase never reached a ferritin level of 3,000 ng/dL. Conclusions There was strong intrapatient correlation between serum ferritin levels and volume transfused but wide interpatient variability early during chronic transfusion therapy. Intrapatient correlation declined at transfusion volumes of more than 250 mL/kg. Direct iron store assessment is needed to determine the clinical significance of serum ferritin variability.

Safety of Purified Poloxamer 188 in Sickle Cell Disease: Phase I Study of a Non‐ionic Surfactant in the Management of Acute Chest Syndrome

Acute chest syndrome (ACS) is the most common cause of death in patients with sickle cell anemia. Its management is primarily palliative. We performed a Phase I evaluation of purified poloxamer 188 (a non‐ionic surfactant) in the management of ACS. Forty‐three patients with sickle cell disease and ACS were treated with doses as high as 2960 mg/day by continuous intravenous (IV) infusion. The maximum tolerated dose has not been identified. No evidence of renal toxicity or other limiting adverse events were found. One adult patient died due to sepsis and adult respiratory distress syndrome, which were unrelated to treatment. Poloxamer 188 is safe to administer to patients with ACS, and preliminary data suggest that it may shorten its duration and the length of hospitalization in a dose related manner. Children appeared to benefit more than adults. The data and safety profile justify further studies with purified poloxamer 188 in the treatment of ACS.

Secretory Phospholipase A2 Levels in Patients with Sickle Cell Disease and Acute Chest Syndrome

In a multicenter study (eight centers), we determined secretory phospholipase A2 (sPLA2) levels in patients with sickle cell disease and acute chest syndrome (ACS). The diagnosis of ACS was made according to established criteria. The sPLA2 levels were determined in blood samples collected at baseline (time of diagnosis) and serially thereafter up to day 22–35 follow-up visits. Thirty-four of 43 (80%) patients with ACS had enzyme levels ≥1.00 AU at baseline. The enzyme levels decreased significantly on Days 2 through Days 25–35 after baseline. Nine of 43 (20%) patients had baseline sPLA2 values of <1.00 AU with six of them never exceeding 1.00 AU at any point in time during follow-up. The data indicate that the reliability of sPLA2 for predicting the development of ACS is not perfect (100%) as was previously reported but occurs in about 80% of the patients.

Sudden onset blindness in sickle cell disease due to retinal artery occlusion

Central retinal artery occlusion (CRAO) is a rare and potentially devastating cause of acute blindness in sickle cell disease (SCD) that is unique compared to classic sickle retinopathy. Few details related to this complication in SCD are known, including its risk factors, pathogenesis, presentation, treatment and outcomes. We present three patients with SCD and retinal artery occlusion. The overall variability in clinical presentation, treatment and prognosis reported in the literature underscores the need for a greater understanding of these factors as they relate to this complication in SCD. Pediatr Blood Cancer 2008;50:624–627.

Efficacy and safety of deferasirox compared with deferoxamine in sickle cell disease: Two‐year results including pharmacokinetics and concomitant hydroxyurea

We report a prospective, randomized, Phase II study of deferasirox and deferoxamine (DFO) in sickle cell disease patients with transfusional iron overload, with all patients continuing on deferasirox after 24 weeks, for up to 2 years. The primary objective was to evaluate deferasirox safety compared with DFO; long‐term efficacy and safety of deferasirox was also assessed. We also report, for the first time, the safety and pharmacokinetics of deferasirox in patients concomitantly receiving hydroxyurea. Deferasirox (n = 135) and DFO (n = 68) had comparable safety profiles over 24 weeks. Adverse events (AEs) secondary to drug administration were reported in 26.7% of patients in the deferasirox cohort and 28.6% in the DFO cohort. Gastrointestinal disorders were more common with deferasirox, including diarrhea (10.4% versus 3.6%) and nausea (5.2% versus 3.6%). The most common AE in the DFO group was injection‐site pain irritation, which occurred in 7% of patients. Acute renal failure occurred in one patient on deferasirox who was continued on medication despite progressive impairment of renal function parameters. Serum ferritin levels were reduced in both treatment groups. Patients continuing on deferasirox for up to 2 years demonstrated an absolute median serum ferritin decrease of −614 ng/mL (n = 96). Increasing deferasirox dose was associated with improved response and a continued manageable safety profile. Concomitant hydroxyurea administration (n = 28) did not appear to influence the efficacy, safety (including liver and kidney function), and pharmacokinetic parameters of deferasirox. Am. J. Hematol. 88:1068–1073, 2013.