scholarly journals Splenomegaly in Children with Sickle Cell Anemia Receiving Hydroxyurea in Sub-Saharan Africa

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 993-993
Author(s):  
Leon Tshilolo ◽  
George A. Tomlinson ◽  
Patrick T. McGann ◽  
Teresa S. Latham ◽  
Peter Olupot-Olupot ◽  
...  
Keyword(s):  
Board Of Directors ◽  
Sickle Cell ◽  
Sickle Cell Anemia ◽  
Growth Parameters ◽  
Sub Saharan Africa ◽  
Advisory Committees ◽  
Splenic Enlargement ◽  
Hydroxyurea Treatment ◽  
Lower Blood ◽  
Sub Saharan

Introduction. Children with sickle cell anemia enrolled in Realizing Effectiveness Across Continents with Hydroxyurea (REACH, NCT01966731) received open-label hydroxyurea at maximum tolerated dose (MTD) in four countries within sub-Saharan Africa (Tshilolo et al, NEJM 2019;380:121-131). Unlike children in the United States or Europe, a substantial proportion of REACH participants had splenomegaly at enrollment, and more developed splenomegaly while receiving hydroxyurea. Splenic enlargement in association with hydroxyurea treatment in sub-Saharan Africa is previously unrecognized, and its causes and consequences remain unclear. Methods. Palpable splenomegaly was evaluated at both the mid-clavicular and mid-axillary lines at each scheduled and unscheduled sick visit. The size of the spleen, defined as the greatest distance (cm) below the subcostal margin, was recorded in the REDCap trial database at all four clinical sites. Cross-sectional analysis was performed at baseline enrollment using four spleen categories (Not Palpable, 1-4 cm, ≥5 cm, or Splenectomy) with correlations for age, sex, site, growth parameters, alpha-thalassemia trait and G6PD deficiency. This analysis was repeated using the largest spleen size over the first two years on hydroxyurea, but examining two-year laboratory values and also the hydroxyurea dose at MTD, time to MTD, dose-limiting toxicities, and clinical outcomes including acute splenic sequestration, malaria infections, and sepsis. Results. A total of 606 children started hydroxyurea study treatment, including 6 (1.0%) with previous splenectomy, 59 (9.7%) with previous splenic sequestration, and 99 (16.3%) with palpable splenomegaly at enrollment (52 children with 1-4 cm and 47 with ≥5 cm). Large spleens (≥5 cm) were commonly observed at baseline at all clinical sites except Uganda, which identified only 1 child. Compared to those with no palpable spleen, children with large spleens at baseline had similar age and growth parameters, but were significantly more likely to have alpha-thalassemia (78.7% versus 56.2%, P=0.004) and also G6PD deficiency among males (28.0% versus 17.6%, P=0.32). Children with large spleens at enrollment also had a lower hemoglobin (Hb = 6.5 versus 7.3 g/dL, P<0.001) and lower platelet count (platelets = 227 versus 410 x 109/L, P<0.001), but equivalent fetal hemoglobin (HbF = 10.2 versus 9.4%, P=0.82). On hydroxyurea treatment with escalation to MTD, 262 children (43.7%) had palpable splenomegaly recorded, including 120 (20.0%) with spleens ≥5 cm. These large spleens were observed at all four clinical sites, with DRC having the most (52) and Uganda with the least (14). After 24 months of hydroxyurea treatment, laboratory differences were noted according to the cumulative occurrence of splenomegaly including a significantly lower hemoglobin and platelet count, higher absolute reticulocyte count, and lower hydroxyurea dose at MTD (Table). Large spleens were associated with a high cumulative incidence of laboratory dose-limiting toxicities, as well as a significantly higher risk of having clinically symptomatic malaria and receiving blood transfusions (Table). A total of 31 children (5.2%) on hydroxyurea treatment received elective splenectomy, including one partial splenectomy using arterial embolization. Conclusion. Children with sickle cell anemia living in sub-Saharan Africa have an increased risk of having palpable splenomegaly, which is further increased while receiving hydroxyurea treatment. Large spleen at baseline were associated with lower blood counts, consistent with hypersplenism. On hydroxyurea treatment, children with large spleens had significantly lower blood counts and more dose-limiting toxicities, which lowered their eventual hydroxyurea dose at MTD but still led to robust HbF responses. Children with large spleens were also at higher risk of developing malaria infections, receiving transfusions, and requiring surgical splenectomy. Splenic enlargement in association with hydroxyurea treatment was common in children with sickle cell anemia in the REACH trial; its cause remains unclear but the consequences include substantial laboratory toxicity and clinical morbidity. Investigating the etiologies and management of children with chronically enlarged spleens is crucial before expanding hydroxyurea access across Africa for sickle cell anemia. Disclosures Ware: Global Blood Therapeutics: Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb: Other: Research Drug Donation; Nova Laboratories: Membership on an entity's Board of Directors or advisory committees; CSL Behring: Membership on an entity's Board of Directors or advisory committees; Novartis: Other: DSMB; Agios: Membership on an entity's Board of Directors or advisory committees; Addmedica: Other: Research Drug Donation.

scholarly journals Effects of Hydroxyurea Treatment on Malaria Infections in Sub-Saharan Africa

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 522-522
Author(s):  
Peter Olupot-Olupot ◽  
George A. Tomlinson ◽  
Teresa S. Latham ◽  
Patrick T. McGann ◽  
Brigida Santos ◽  
...  
Keyword(s):  
Risk Factor ◽  
Board Of Directors ◽  
Dose Escalation ◽  
Blood Smear ◽  
Malaria Risk ◽  
Sub Saharan Africa ◽  
Advisory Committees ◽  
Hydroxyurea Treatment ◽  
Sub Saharan ◽  
Research Drug

Introduction. Realizing Effectiveness Across Continents with Hydroxyurea (REACH, NCT01966731) is a prospective multicenter open-label trial that has already demonstrated hydroxyurea treatment at maximum tolerated dose (MTD) is safe, feasible, and offers major benefits for children with sickle cell anemia living in sub-Saharan Africa (Tshilolo et al, NEJM 2019;380:121-131). One unexpected benefit was a significant reduction in the number of malaria infections, including those with Grade 3 severity or above, across four trial sites in varied epidemiological settings. The overall rate of symptomatic malaria infections decreased from 46.9 events per 100 patient-years during screening to 22.9 events per 100 patient-years on treatment, an incidence rate ratio of 0.49 (95% confidence intervals [CI] = 0.37-0.66). This decreased rate of malaria was observed during the first 12 months of treatment, but declined further between Months 12-36, after the children had dose escalation to achieve hydroxyurea MTD at 22.5 mg/kg/day. Potential mechanisms of malaria protection remain unknown at this time, but could relate to both patient characteristics as well as treatment-related laboratory changes in hemoglobin (Hb), mean corpuscular volume (MCV), absolute neutrophil count (ANC), or fetal hemoglobin (HbF). Methods. Malaria infections were recorded in the REACH REDCap electronic database. Using several methods for recurrent events, with time-varying predictors as well as landmark analysis, associations with infections recorded during study treatment were assessed for multiple variables including trial site, high or low malaria season, age, gender, spleen status, hydroxyurea dose, MTD status, latest laboratory values (Hb, MCV, ANC, and HbF, all measured at least 15 days prior to the onset of the infection), as well as genetic modifiers alpha-thalassemia and G6PD deficiency. Univariate relationships were assessed using the Anderson-Gill model, followed by multiple regression to estimate Hazard Ratios (HR) with 95% CI's. Additional analyses were performed using a gap-time model that resets the clock after each infection, as well as using only the first infection in each participant; the subset of 200 acute blood-smear proven malaria infections was also analyzed separately. Results. A total of 635 children were enrolled in REACH and eligible for analysis, of whom 606 started hydroxyurea treatment. There were 333 malaria infections recorded during 1580 patient-years of observation, including 50 during screening and 283 on treatment, of which 200 had documented positive blood smears at the clinical site. Significant associations for malaria risk were identified with higher ANC (HR = 1.06 per 1 x 109 neutrophils/L, CI = 1.02-1.10, P=0.005), higher MCV (HR = 1.01 per fL, CI = 1.00-1.02), and palpable splenomegaly (HR 1-4cm = 1.73, CI = 1.22-2.45, P= 0.002, HR ≥5cm = 1.52, CI = 1.04-2.21, P=0.03). In multiple regression, the latest ANC and MCV, as well as splenomegaly remained significant but higher HbF was also associated with more malaria (HR = 1.02 per %HbF, CI = 1.00-1.03, P=0.03). These trends were consistent when using the landmark, gap-time and first infection analytical approaches. Analysis of only documented blood-smear positive malaria infections again identified higher ANC, MCV, and splenomegaly as risk factors, but found no association with HbF. Achieving MTD was found to confer significant protection against documented malaria infections (HR = 0.62, CI=0.39-1.00, P=0.048). Conclusion. Hydroxyurea treatment in children with sickle cell anemia living in sub-Saharan Africa is associated with a decreased risk of malaria infections, particularly after achieving MTD. The mechanisms by which hydroxyurea protects against malaria are likely multi-factorial, but do not appear to be related to HbF induction, as higher HbF values were not protective and in some analyses were a risk factor. However, a higher ANC was significantly associated with malaria risk in all models and analyses; since hydroxyurea treatment lowers the ANC, dose escalation to MTD may confer protection against malaria infection by reducing inflammation. Spleen status is also crucial and the role of splenomegaly as a risk factor for malaria requires further investigation. Disclosures Ware: Novartis: Other: DSMB; Agios: Membership on an entity's Board of Directors or advisory committees; Nova Laboratories: Membership on an entity's Board of Directors or advisory committees; CSL Behring: Membership on an entity's Board of Directors or advisory committees; Addmedica: Other: Research Drug Donation; Bristol Myers Squibb: Other: Research Drug Donation; Global Blood Therapeutics: Membership on an entity's Board of Directors or advisory committees.

scholarly journals Novel Use of Hydroxyurea in an African Region with Malaria (NOHARM): A Randomized Controlled Trial

Blood ◽  
2017 ◽  
Vol 130 (Suppl_1) ◽  
pp. 759-759
Author(s):  
Robert Opoka ◽  
Christopher Ndugwa ◽  
Teresa S. Latham ◽  
Adam Lane ◽  
Heather Ann Hume ◽  
...  
Keyword(s):  
Adverse Events ◽  
Sickle Cell ◽  
Research Funding ◽  
Malaria Incidence ◽  
Controlled Trial ◽  
Sub Saharan Africa ◽  
Number Needed To Treat ◽  
Hydroxyurea Treatment ◽  
Sub Saharan ◽  
Double Blinded

Abstract Background. Hydroxyurea treatment is recommended for children with sickle cell anemia (SCA) living in high-resource malaria-free regions, but its safety and efficacy in malaria-endemic settings such as sub-Saharan Africa, where the greatest sickle cell burden exists, remain unknown. In vitro studies suggest hydroxyurea could increase malaria severity, through upregulation of intracellular adhesion molecule 1 (ICAM-1) that facilitates parasite adhesion to endothelium. In addition, hydroxyurea-associated neutropenia could worsen infections that occur in low-resource settings. Methods. NOHARM (NCT01976416) was a randomized, double-blinded, placebo-controlled trial conducted in malaria-endemic Uganda. Children between the ages of 1.00-3.99 years were enrolled, and then received 12-months of blinded treatment with either hydroxyurea or placebo at 20 ± 2.5 mg/kg/day, with dose adjustments in both arms for weight gain and hematological toxicities. All participants received standard care for SCA including folic acid, penicillin prophylaxis, and pneumococcal vaccination. For malaria prophylaxis, children received insecticide-treated mosquito nets and monthly sulphadoxine-pyrimethamine. The primary outcome was incidence of clinical malaria. Secondary outcomes included SCA-related adverse events, clinical and laboratory effects, and hematological toxicities. After completing the blinded treatment phase, all participants were offered open-label hydroxyurea, as per local Ethics Committee recommendations. Results. Study participants (median age 2.2 years) received either hydroxyurea (N=104) or placebo (N=103) for 12-months. Malaria occurred at a low rate throughout the study. The malaria incidence did not differ between children on hydroxyurea [0.05 episodes/child/year, 95% CI (0.02, 0.13)] versus placebo [0.07 episodes/child/year (0.03, 0.16)]. The hydroxyurea/placebo malaria incidence rate ratio was 0.7 [(0.2, 2.7), p=0.61], and time to infection did not differ significantly between treatment arms. A composite SCA-related clinical outcome (vaso-occlusive painful crisis, dactylitis, acute chest syndrome, splenic sequestration, or blood transfusion) was less frequent with hydroxyurea (45%) than placebo (69%, p=0.001). For individual clinical events, vaso-occlusive pain and hospitalizations were significantly less frequent with hydroxyurea than placebo; the number needed to treat to prevent one hospitalization was 6.4, while the number needed to treat to prevent a SCA-related event was 2.5. Serious adverse events, sepsis episodes, and dose-limiting toxicities were similar between treatment arms. Specifically, low hemoglobin (<6.0 g/dL) occurred more frequently in children receiving placebo than hydroxyurea, while the frequencies of neutropenia, thrombocytopenia and reticulocytopenia did not differ significantly between treatment arms. Three deaths occurred (two hydroxyurea, one placebo, none from malaria). Children receiving hydroxyurea had significantly increased hemoglobin concentration and fetal hemoglobin, along with decreased leukocytes, neutrophils, and reticulocytes. Conclusions. In this prospective randomized double-blinded placebo-controlled trial of young children with SCA living in Uganda, hydroxyurea therapy was both safe and efficacious. Based on these NOHARM data, hydroxyurea treatment appears safe for children with SCA living in malaria-endemic sub-Saharan Africa, without increased risk for severe malaria, infections, or adverse events. Hydroxyurea provides predicted SCA-related laboratory and clinical efficacy, but the optimal dosing and monitoring regimens for affected children in Africa remain undefined. Disclosures Ware: Agios: Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb: Research Funding; Addmedica: Research Funding; Nova Laboratories: Consultancy; Global Blood Therapeutics: Consultancy.

scholarly journals Sickle Stroke Screen: A Patient-Centered Educational Initiative for Children with Sickle Cell Anemia in the Displace Consortium

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 43-44
Author(s):  
Alyssa M Schlenz ◽  
Shannon Phillips ◽  
Martina Mueller ◽  
Cathy L Melvin ◽  
Robert J Adams ◽  
...  
Keyword(s):  
Needs Assessment ◽  
Board Of Directors ◽  
Sickle Cell ◽  
Sickle Cell Anemia ◽  
Stroke Prevention ◽  
Stroke Risk ◽  
Advisory Board ◽  
Educational Initiative ◽  
Advisory Committees ◽  
Board Membership

Introduction: The NHLBI funded Dissemination and Implementation of Stroke Prevention Looking at the Care Environment (DISPLACE) study was designed to improve implementation of stroke prevention guidelines in children with sickle cell anemia (SCA), particularly implementation of transcranial Doppler (TCD) ultrasound for identifying individuals at risk of stroke. The study consists of 3 phases: 1) evaluating current stroke risk screening practices, 2) exploring barriers and facilitators to guideline implementation (needs assessment), and 3) designing and implementing interventions to improve stroke risk screening. A key barrier identified through qualitative methods during the needs assessment was a gap in education, including an overall lack of understanding among patients and caregivers of the purpose of TCD screening. This abstract describes the process of developing one of the interventions for phase 3, a rebranding and educational initiative. Methods: During the needs assessment, 27 key informant interviews and 173 complete surveys were conducted with individuals with SCA and their caregivers. Transcripts from the interviews and survey responses were reviewed to better understand the extent of educational gaps described by families as well as to guide initial rebranding prototypes. Prototypes were developed by the study team, including a new name and logo for TCD as well as an infographic. An interview guide was then created to obtain feedback on the prototypes from individuals with SCA and/or the parent or primary caregiver from two sites in the consortium. Cue cards with prototypes were included with prompts for the "think aloud" method to be applied during interviews. Cue cards were presented first with prototypes for the new name in black font on a white background to solicit feedback on the wording alone. Then, cue cards included various layouts, fonts, and graphics with the prototype names for in-depth feedback on the logo appearance. Finally, participants were asked questions pertaining to the infographic. Results: Twenty interviews were conducted with individuals with SCA and/or the parent/caregiver at two DISPLACE sites. Almost all participants (95%) made the connection between the wording prototypes and TCD without prompting. Many participants expressed that the word "stroke" in both options was "scary," and sometimes chose the option that was "less scary to them." However, many participants also felt that the word "stroke" was necessary to explain the reason for the procedure and would prompt families to ask about the screening as opposed to making them more fearful. The majority of participants (60%) chose "Sickle Stroke Screen" over "Stroke Risk Screen." Participants reported preferring this wording because it is specific to SCA, was easier to remember and represented a less "scary" option. The most commonly preferred logo is presented in Figure 1. Participant reasons for selecting this option were: it is easier to read; they preferred the stacked layout; it is less spread out; they liked the bold letters; it is more eye catching; and it includes the words "sickle cell" in the logo. When asked about preferences for an infographic, the majority described including a picture of a brain. Nearly all participants believed a reassuring message was needed to balance out the fear of the word "stroke." The message, "knowledge is power" provided this balance and resonated with nearly all participants (95%). Figure 2 presents the infographic developed based on participant feedback. Conclusions: Results from this educational rebranding effort highlight the importance of understanding patient and family educational gaps and incorporating their perspective and feedback into educational campaigns. The new logo and infographic were integrated into an educational pamphlet, informative posters and other material designed by the DISPLACE site principal investigators. Part 3 of the study is underway including implementation of the educational initiative at the DISPLACE sites. The new terminology and logo have also been broadly distributed throughout the US through community-based organizations to other patients, families, and stakeholders. Disclosures Kanter: AGIOS: Membership on an entity's Board of Directors or advisory committees; NHLBI Sickle Cell Advisory Board: Membership on an entity's Board of Directors or advisory committees; SCDAA Medical and Research Advisory Board: Membership on an entity's Board of Directors or advisory committees; Wells Fargo: Honoraria; Jeffries: Honoraria; Cowen: Honoraria; bluebird bio, inc: Consultancy, Honoraria; Novartis: Consultancy; Sanofi: Consultancy; Medscape: Honoraria; Guidepoint Global: Honoraria; GLG: Honoraria; BEAM: Membership on an entity's Board of Directors or advisory committees.

scholarly journals Optimizing hydroxyurea therapy for sickle cell anemia

Hematology ◽  
2015 ◽  
Vol 2015 (1) ◽  
pp. 436-443 ◽  
Author(s):  
Russell E. Ware
Keyword(s):  
Sickle Cell ◽  
Sickle Cell Anemia ◽  
Fetal Hemoglobin ◽  
Maximum Tolerated Dose ◽  
Sub Saharan Africa ◽  
Future Research ◽  
Published Evidence ◽  
Treatment Indications ◽  
Hydroxyurea Treatment ◽  
Hydroxyurea Therapy

Abstract Hydroxyurea has proven efficacy in numerous clinical trials as a disease-modifying treatment for patients with sickle cell anemia (SCA) but is currently under-used in clinical practice. To improve the effectiveness of hydroxyurea therapy, efforts should be directed toward broadening the clinical treatment indications, optimizing the daily dosage, and emphasizing the benefits of early and extended treatment. Here, various issues related to hydroxyurea treatment are discussed, focusing on both published evidence and clinical experience. Specific guidance is provided regarding important but potentially unfamiliar aspects of hydroxyurea treatment for SCA, such as escalating to maximum tolerated dose, treating in the setting of cerebrovascular disease, switching from chronic transfusions to hydroxyurea, and using serial phlebotomy to alleviate iron overload. Future research directions to optimize hydroxyurea therapy are also discussed, including personalized dosing based on pharmacokinetic modeling, prediction of fetal hemoglobin responses based on pharmacogenomics, and the risks and benefits of hydroxyurea for non-SCA genotypes and during pregnancy/lactation. Another critical initiative is the introduction of hydroxyurea safely and effectively into global regions that have a high disease burden of SCA but limited resources, such as sub-Saharan Africa, the Caribbean, and India. Final considerations emphasize the long-term goal of optimizing hydroxyurea therapy, which is to help treatment become accepted as standard of care for all patients with SCA.

Effect of a comprehensive clinical care program on disease course in severely ill children with sickle cell anemia in a sub-Saharan African setting

Blood ◽  
2003 ◽  
Vol 102 (3) ◽  
pp. 834-838 ◽  
Author(s):  
Mohamed Cherif Rahimy ◽  
Annick Gangbo ◽  
Gilbert Ahouignan ◽  
Roselyn Adjou ◽  
Chantal Deguenon ◽  
...  
Keyword(s):  
Sickle Cell ◽  
Sickle Cell Anemia ◽  
Parental Education ◽  
Clinical Care ◽  
Care Program ◽  
Clinical Severity ◽  
Sub Saharan Africa ◽  
Physical Growth ◽  
Sub Saharan ◽  
African Setting

Abstract Clinical severity of sickle cell anemia (SS) in Africa may not be solely determined by genetic factors. This study evaluated the effects of intensive parental education and adequate clinical care on the course of SS in children in Benin. SS children referred to the National Teaching Hospital in Cotonou were included in the study. Teaching about SS was repeated frequently, emphasizing the importance of keeping clinic appointments, improving the nutrition of the affected children, and instituting antipneumococcal and antimalarial prophylaxis. Frequency and severity of SS-related events, changes in physical growth, frequency of malarial attacks, causes of transfusion, and causes of death were the principal variables assessed. 236 young children with repeated SS-related acute complications were studied from July 1, 1993, to December 31, 1999 (983 patient-years). A marked reduction in the frequency and severity of SS-related acute events was observed. Improvement in general status and physical growth was noted in 184 patients (78%); in addition, 22 of the remaining 52 patients showed similar improvement after remotivating the parents for compliance. There were 10 deaths, primarily in this cohort of 52 patients. Intensive sociomedical intervention can produce sustained clinical improvement in many severely ill SS children in sub-Saharan Africa.

scholarly journals Iron Unloading By Therapeutic Phlebotomy in Previously Transfused Children with Sickle Cell Anemia: The Twitch Experience

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 1018-1018 ◽  
Author(s):  
Banu Aygun ◽  
Nicole Mortier ◽  
Zora R. Rogers ◽  
William Owen ◽  
Beng Fuh ◽  
...  
Keyword(s):  
Iron Overload ◽  
Board Of Directors ◽  
Sickle Cell ◽  
Sickle Cell Anemia ◽  
Research Funding ◽  
Chelation Therapy ◽  
Venous Access ◽  
Study Entry ◽  
Iron Loading ◽  
Advisory Committees

Abstract Background: TCD With Transfusions Changing to Hydroxyurea (TWiTCH, ClinicalTrials.gov NCT01425307), an NHLBI-sponsored Phase III multicenter trial, compared transfusions to hydroxyurea for maintaining TCD velocities in children with sickle cell anemia who previously received transfusions for abnormal TCD velocities. Iron overload was treated with serial phlebotomy in children randomized to hydroxyurea. At the first scheduled interim analysis, non-inferiority of hydroxyurea was demonstrated and the study was terminated prematurely. Methods: Participants randomized to hydroxyurea received decreasing volumes of monthly transfusions during hydroxyurea dose escalation to maximum tolerated dose (MTD), averaging 6-7 months. During this transfusion overlap period, no chelation therapy was given. After hydroxyurea MTD was reached, transfusions were discontinued and children started monthly phlebotomy if their entry liver iron concentration (LIC) by MRI-R2 (FerriScan®) was ≥2 mg Fe/g dry weight liver (DWL). The prescribed phlebotomy volume was 10 mL/kg (maximum 500 mL) with adjustments for anemia (5 mL/kg for Hb 8.0-8.5 g/dL and held if Hb <8.0 g/dL). Phlebotomy was performed over 30 minutes with immediate equal volume normal saline replacement, typically using peripheral venous access. LIC was assessed at study entry, midpoint (12 months), and exit (24 months/early closure). Ferritin was monitored monthly using a centralized laboratory. Iron loading calculations were based on actual transfusion and phlebotomy volumes. Results: Sixty children (mean age 9.7±3.2 years; range 5.2-19.0 years; 48% male) were randomized to the Hydroxyurea Treatment Arm. The average duration of previous transfusions was 4.5±2.8 years. Almost all (51/60, 85%) had previously received chelation, primarily deferasirox, and 48 (80%) were on chelation therapy at study enrollment. Hydroxyurea MTD was achieved in 57 children (95%), and 54 commenced phlebotomy (two had low iron burden with LIC <2 and one had Hb <8.0 g/dL). A total of 914 phlebotomy procedures were scheduled per protocol for these 54 children and 756 (83%) were fully completed. There were 77 procedures cancelled due to anemia and another 81 procedures cancelled due to planned anesthesia (16), provider preference (14), hydroxyurea-related cytopenia (13), intercurrent illness (11), inadequate iv access (9), family request (5) or other (13). In 94% of phlebotomy procedures that were initiated, the full volume was removed; for the remaining 6% (47 procedures), a reduced volume was removed due to loss of venous access (37), symptoms such as headache or lightheadedness (7), or other reasons (3). A total of 18 Adverse Events (17 Grade 2 and one Grade 3) occurred in 14 participants in association with phlebotomy (2.3% prevalence). The most common complication was light headedness/near-syncope (6) followed by anemia (4), hypotension (3), headache (3), and pain at the venous access site (1). One subject had a syncopal episode followed by transient weakness, which was centrally adjudicated as TIA. An average of 53.6±21.8 mL/kg blood was administered in the hydroxyurea-treated arm, which calculates to an average iron loading of 40.1±16.3 mg Fe/kg, while an average of 112 mL/kg of venous blood was removed by phlebotomy, which calculates to an average iron unloading of 36.1±15.7 mg Fe/kg. For the 54 children who received phlebotomy, the average LIC was 12.0± 9.7 mg/g at study entry, 13.4±10.3 at midpoint reflecting overlap transfusions without chelation, and 9.7±8.9 at study exit reflecting serial phlebotomy, for an average net LIC decrease of 2.3±4.1 mg/g. Average serum ferritin at study entry was 3105±741 ng/mL and 1392±1542 ng/mL at study exit. For 39 children who completed all 24 months of treatment before study closure, the overall average LIC decrease was 3.2±3.8 mg/gram DWL and 10 had final LIC measurements <3 mg Fe/g. Calculated net iron loading was not significantly associated with measured changes in LIC or ferritin. Conclusions: In the TWiTCH trial, phlebotomy was a feasible, safe, well-tolerated, and effective treatment for transfusional iron overload in children with sickle cell anemia. Although initial overlap transfusions without chelation limited the phlebotomy effects, in children who reached hydroxyurea MTD and discontinued chronic transfusions, monthly phlebotomy led to net iron unloading and lower LIC, and significantly reduced iron burden. Disclosures Rogers: Apopharma: Consultancy. Kalfa:Baxter/Baxalta/Shire: Research Funding. Kwiatkowski:Sideris Pharmaceuticals: Consultancy; Luitpold Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Apopharma: Research Funding; Ionis pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Shire Pharmaceuticals: Consultancy. Wood:World Care Clinical: Consultancy; Biomed Informatics: Consultancy; Biomed Informatics: Consultancy; Celgene: Consultancy; Celgene: Consultancy; AMAG: Consultancy; Apopharma: Consultancy; Apopharma: Consultancy; AMAG: Consultancy; World Care Clinical: Consultancy; Vifor: Consultancy; Vifor: Consultancy; Ionis Pharmaceuticals: Consultancy; Ionis Pharmaceuticals: Consultancy. Ware:Global Blood Therapeutics: Consultancy; Biomedomics: Research Funding; Bayer Pharmaceuticals: Consultancy; Addmedica: Research Funding; Nova Laboratories: Consultancy; Bristol Myers Squibb: Research Funding.

scholarly journals Outcomes in Children with Severe Vasculopathy from Sickle Cell Anemia after Treatment with Chronic Transfusion, Surgical Revascularization and/or Allogenic Hematopoetic Stem Cell Transplantation

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 1098-1098
Author(s):  
Courtney W. Johnson ◽  
Suvankar Majumdar ◽  
Andrew D. Campbell ◽  
Suresh Magge ◽  
Deepika S. Darbari ◽  
...  
Keyword(s):  
Stem Cell ◽  
Board Of Directors ◽  
Sickle Cell ◽  
Sickle Cell Anemia ◽  
Research Funding ◽  
Moyamoya Syndrome ◽  
Surgical Revascularization ◽  
Advisory Committees ◽  
Time Of Intervention

Abstract Background: Cerebral vasculopathy is a frequent complication of sickle cell anemia (SCA) and is associated with a high risk for stroke. This vasculopathy seen in SCA can be progressive and severe. Sickle cell patients with severe vasculopathy, including Moyamoya syndrome are at increased risk for neurological disabilities and death. While chronic transfusions decrease the risk of stroke in SCA; unfortunately, progression of vasculopathy can occur despite treatment. Limited data exists regarding long term outcomes for this population. We evaluated effectiveness of three treatment approaches at our center, namely chronic transfusions, surgical revascularization plus chronic transfusions and allogenic hematopoietic stem cell transplant (HSCT). Methods: A retrospective chart review was preformed to identify patients with SCA (hemoglobin SS, Sβ0) and severe vasculopathy including Moyamoya syndrome between 1986 to 2017. Severe vasculopathy was defined as having at least one cerebral artery with > 70% stenosis and/or occlusion as seen on MR angiogram (MRA), CT angiogram (CTA) or conventional angiogram (DSA) as determined by a neuroradiologist at our institution. Patients were identified from an institutional stroke database. Patients were included for analysis if they received at least one of the following: chronic transfusions, surgical revascularization (i.e. encephalo-duro-arterio-synagiosis (EDAS) plus chronic transfusions or HSCT. For HSCT, all graft types (bone marrow, peripheral blood stem cells, umbilical cord blood), conditioning regimens and donor types (related, unrelated and haploidentical) were included. Time to event analyses were performed from the time of intervention (transfusion, HSCT, EDAS/chronic transfusions) using overt clinical stroke, new silent infarcts, progression of vasculopathy or new vasculopathy. Survival curves were analyzed using the log-rank (Mantel-Cox) test. Results: Of 35 patients identified, 54% (n =19) underwent chronic transfusions, 23% (n=8) of patients underwent HSCT after being on chronic transfusions, 23% (n=8) underwent EDAS with chronic transfusions and 1 patient underwent each of the above three modalities (Table 1). Median age at time of intervention was similar for all three cohorts (Table 1). Males were overrepresented in all treatment arms (62.5-79% of patients). Average hemoglobin level prior to intervention was also similar: 7.6 g/dL (IQR 7.1-8.3) for the chronic transfusion cohort, 7.3 gm/dL (IQR 6.3-8.2) for the HSCT cohort, and 7.5 gm/dL (IQR 7.2-8) for the EDAS/chronic transfusion cohort. Absolute reticulocyte count was 492.9 K/ul (IQR 358.4-550) for the chronic transfusion group, 389.4 (IQR 174.3-449) for HSCT, and 250.2 (IQR 107.3-393) for EDAS/chronic transfusions (p=0.08). One patient died of overt stroke in the chronic transfusion cohort. The median follow-up times for the transfusion, HSCT and EDAS plus transfusion groups were 4.4, 2.4 and 6 years respectively. Time from date of intervention (transfusion, HSCT, EDAS) to overt clinical or silent stroke was evaluated (Fig 1). Two of the nineteen patients in the chronic transfusion cohort suffered an overt stroke, while one of eight and two of eight had strokes in the post-HSCT and EDAS plus chronic transfusion cohorts respectively. Fourteen of nineteen (74%) in the chronic transfusion cohort had progression of severe vasculopathy after being on transfusions while two of eight (25%) in the HSCT and four of the eight (50%) patients in the EDAS plus chronic transfusion cohorts had progression. The one patient with all three different interventions did not have additional infarction (clinical or silent) or vasculopathy progression during 1.5 years of follow-up. Conclusions: The risk for cerebral infarction and/or vasculopathy progression after initiation of treatment with either chronic transfusion, HSCT or EDAS is still a major concern. Our data suggest HSCT and surgical revascularization with chronic transfusion provide the greatest benefit in reducing stroke risk and HSCT reduces risk for progression of a severe vasculopathy. Additional, large population studies are needed to clarify the risk. Disclosures Majumdar: NIMHD: Research Funding. Campbell:Functional Fluitics: Membership on an entity's Board of Directors or advisory committees; Global Blood Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding.

Optimizing hydroxyurea therapy for sickle cell anemia

Hematology ◽  
2015 ◽  
Vol 2015 (1) ◽  
pp. 436-443 ◽  
Author(s):  
Russell E. Ware
Keyword(s):  
Sickle Cell ◽  
Sickle Cell Anemia ◽  
Fetal Hemoglobin ◽  
Maximum Tolerated Dose ◽  
Sub Saharan Africa ◽  
Future Research ◽  
Published Evidence ◽  
Treatment Indications ◽  
Hydroxyurea Treatment ◽  
Hydroxyurea Therapy

Hydroxyurea has proven efficacy in numerous clinical trials as a disease-modifying treatment for patients with sickle cell anemia (SCA) but is currently under-used in clinical practice. To improve the effectiveness of hydroxyurea therapy, efforts should be directed toward broadening the clinical treatment indications, optimizing the daily dosage, and emphasizing the benefits of early and extended treatment. Here, various issues related to hydroxyurea treatment are discussed, focusing on both published evidence and clinical experience. Specific guidance is provided regarding important but potentially unfamiliar aspects of hydroxyurea treatment for SCA, such as escalating to maximum tolerated dose, treating in the setting of cerebrovascular disease, switching from chronic transfusions to hydroxyurea, and using serial phlebotomy to alleviate iron overload. Future research directions to optimize hydroxyurea therapy are also discussed, including personalized dosing based on pharmacokinetic modeling, prediction of fetal hemoglobin responses based on pharmacogenomics, and the risks and benefits of hydroxyurea for non-SCA genotypes and during pregnancy/lactation. Another critical initiative is the introduction of hydroxyurea safely and effectively into global regions that have a high disease burden of SCA but limited resources, such as sub-Saharan Africa, the Caribbean, and India. Final considerations emphasize the long-term goal of optimizing hydroxyurea therapy, which is to help treatment become accepted as standard of care for all patients with SCA.

scholarly journals Stroke Avoidance for Children in República Dominicana (SACRED):a Prospective Trial to Reduce Stroke in Children with Sickle Cell Anemia

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 2285-2285
Author(s):  
Luisanna Sanchez ◽  
Rosa M. Nieves ◽  
Teresa S. Latham ◽  
Adam Lane ◽  
Neelum Jeste ◽  
...  
Keyword(s):  
Dominican Republic ◽  
Board Of Directors ◽  
Sickle Cell Anemia ◽  
Dose Escalation ◽  
Stroke Prevention ◽  
Stroke Risk ◽  
Open Label ◽  
Advisory Committees ◽  
Hydroxyurea Treatment ◽  
Research Drug

Introduction. The burden of sickle cell anemia (SCA) is high across the Caribbean, including the Dominican Republic where the morbidity of SCA is substantial due to limited resources. Approximately 10% of affected children will develop primary stroke, with serious medical and neurocognitive sequelae. In the US, transcranial Doppler (TCD) ultrasonography is an effective screening tool to identify children at risk for primary stroke, which then allows preventive therapy with either hydroxyurea or blood transfusions. To date, however, no routine TCD screening and treatment program for stroke prevention has been established in the Dominican Republic. We designed a prospective screening and treatment study (SACRED, NCT02769845) for prevention of primary stroke in children with SCA using open-label hydroxyurea at maximum tolerated dose (MTD). Methods. Children with SCA between age 3-15 years and receiving medical care at Robert Reid Cabral Children's Hospital in Santo Domingo, Dominican Republic were recruited over a 12-month period. Treatment depended on the baseline TCD examination: children with abnormal time-averaged mean velocities (≥200 cm/sec, high stroke risk) were recommended to receive monthly transfusions for primary stroke prevention, as per standard treatment preferences at the Robert Reid Hospital; those with conditional velocities (170-199 cm/sec, moderate stroke risk) were offered hydroxyurea study treatment unless they were currently receiving chronic transfusions for other clinical indications. Oral open-label hydroxyurea using 500mg capsules was prescribed at fixed-dose (20 mg/kg/day) for 6 months, followed by dose escalation to MTD. TCD examinations were repeated every 6 months, with the main study endpoints being changes in laboratory parameters and TCD velocities after 18 months of study treatment. Results. A total of 283 children were enrolled with the following baseline TCD velocities: 200 (70.7%) normal, 63 (22.3%) conditional, 11 (3.9%) abnormal, and 9 (3.1%) inadequate velocities. Among 50 children eligible for hydroxyurea study treatment, the average age was 6.8 ± 2.8 years and included 27 males/23 females with evidence of substantial SCA-related morbidity (88% with previous transfusions, 60% with >5 hospitalizations). A total of 48 children initiated hydroxyurea at 20.2 ± 1.2 mg/kg/day, which was maintained for 6 months followed by dose escalation, reaching MTD at 24.1 ± 6.0 mg/kg/day. Laboratory changes from baseline to Month 18 included significant increases in hemoglobin (7.5 ± 0.9 to 8.9 ± 1.3 g/dL, P<0.0001) and fetal hemoglobin (16.4 ± 7.4 to 30.9 ± 13.6%, P<0.0001). Serial TCD examinations revealed a significant decline over the treatment period, with the average TCD velocity decreasing from 180 ± 8 cm/sec at baseline to 159 ± 21 cm/sec at Month 18, P<0.0001. At Month 18, 68% of the originally conditional TCD examinations had reverted to a normal velocity, while only 4% had converted to abnormal velocity. No clinical strokes occurred in the hydroxyurea treatment cohort. Conclusion. Conditional TCD velocities are common (>20%) in the Dominican Republic, which documents an elevated stroke risk for children with SCA. The SACRED trial established a local TCD screening program and provided open-label hydroxyurea treatment for children with conditional TCD velocities. Hydroxyurea treatment at MTD led to improved hematological parameters, lower TCD velocities, and decreased stroke risk. SACRED represents an important international partnership and prospective collaborative research trial providing capacity building and valuable epidemiological data regarding TCD screening, stroke risk, and hydroxyurea effects for children with SCA. Hydroxyurea at MTD is a suitable treatment to reduce primary stroke risk for children with SCA living in the Dominican Republic or other low-resource settings. Disclosures Jeste: Jannsen: Employment. Ware:Novartis: Other: DSMB; Nova Laboratories: Membership on an entity's Board of Directors or advisory committees; CSL Behring: Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb: Other: Research Drug Donation; Addmedica: Other: Research Drug Donation; Global Blood Therapeutics: Membership on an entity's Board of Directors or advisory committees; Agios: Membership on an entity's Board of Directors or advisory committees.

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