Association of hydroxyurea adherence with transcranial Doppler screenings in children with sickle cell disease.

BACKGROUND: National sickle cell disease (SCD) guidelines recommend oral hydroxyurea (HU) starting at 9 months of age, and annual transcranial Doppler (TCD) screenings to identify stroke risk in children aged 2-16 years. We examined prevalence and proportion of TCD screenings in North Carolina Medicaid enrollees to identify associations with sociodemographic factors and HU adherence over 3 years. STUDY DESIGN: We conducted a longitudinal study with children ages 2-16 years with SCD enrolled in NC Medicaid from years 2016-2019. Prevalence of TCD screening claims was calculated for 3 years, and proportion was calculated for 12, 24, and 36 months of Medicaid enrollment. Enrollee HU adherence was categorized using HU proportion of days covered. Multivariable Poisson regression assessed for TCD screening rates by HU adherence, controlling for age, sex, and rurality. RESULTS: The prevalence of annual TCD screening was between 39.5% and 40.1%. Of those with 12-month enrollment, 77.8% had no TCD claims, compared to 22.2% who had one or higher TCD claims. Inversely, in children with 36 months of enrollment, 36.7% had no TCD claims compared to 63.3% who had one or higher TCD claims. The proportion of children with two or higher TCD claims increased with longer enrollment (10.5% at 12 months, 33.7% at 24 months, and 52.6% at 36 months). Children with good HU adherence were 2.48 (p < .0001) times more likely to have TCD claims than children with poor HU adherence. CONCLUSION: While overall TCD screening prevalence was low, children with better HU adherence and longer Medicaid enrollment had more TCD screenings. Multilevel interventions are needed to engage healthcare providers and families to improve both evidence-based care and annual TCD screenings in children with SCD.

Hydroxyurea dose optimisation for children with sickle cell anaemia in sub-Saharan Africa (REACH): extended follow-up of a multicentre, open-label, phase 1/2 trial.

BACKGROUND: Realizing Effectiveness Across Continents with Hydroxyurea (REACH) is an open-label non-randomised trial of hydroxyurea (hydroxycarbamide) in children with sickle cell anaemia in sub-Saharan Africa. The short-term results of REACH on safety, feasibility, and effectiveness of hydroxyurea were published previously. In this paper we report results from extended hydroxyurea treatment in the REACH cohort up to 8 years. METHODS: In this open-label, non-randomised, phase 1/2 trial, participants were recruited from four clinical sites in Kilifi, Kenya; Mbale, Uganda; Luanda, Angola; and Kinshasa, Democratic Republic of Congo. Eligible children were 1-10 years old with documented haemoglobin SS or haemoglobin Sß zero thalassaemia, weighing at least 10 kg. Participants received fixed-dose hydroxyurea of 17.5 (±2.5) mg/kg per day for 6 months (fixed-dose phase), followed by 6 months of dose escalation (2·5-5·0 mg/kg increments every 8 weeks) as tolerated, up to 20-35 mg/kg per day (maximum tolerated dose; MTD), defined as mild myelosuppression. After the MTD was reached, hydroxyurea dosing was optimised for each participant on the basis of changes in bodyweight and laboratory values over time (MTD with optimisation phase). After completion of the first 12 months, children with an acceptable toxicity profile and favourable responses were given the opportunity to continue hydroxyurea until the age of 18 years. The safety and feasibility results after 3 years has been reported previously. Here, haematological responses, clinical events, and toxicity rates were compared across the dosing phases (fixed-dose hydroxyurea vs MTD with optimisation phase) as protocol-specified outcomes. REACH is registered on ClinicalTrials.gov (NCT01966731) and is ongoing. FINDINGS: We enrolled 635 children between July 4, 2014, and Nov 11, 2016. 606 children were given hydroxyurea and 522 (86%; 266 [51%] boys and 256 [49%] girls) received treatment for a median of 93 months (IQR 84-97) with 4340 patient-years of treatment. The current (Oct 5, 2023) mean dose is 28·2 (SD 5·2) mg/kg per day with an increased mean haemoglobin concentration (7·3 [SD 1·1] g/dL at baseline to 8·5 [1·5] g/dL) and mean fetal haemoglobin level (10·9% [SD 6·8] to 23·3% [9·5]) and decreased absolute neutrophil count (6·8 [3·0] × 109 cells per L to 3·6 [2·2] × 109 cells per L). Incidence rate ratios (IRR) comparing MTD with fixed-dose hydroxyurea indicate decreased vaso-occlusive episodes (0·60; 95% CI 0·52-0·70; p<0·0001), acute chest syndrome events (0·21; 0·13-0·33; p<0·0001), recurrent stroke events (0·27; 0·07-1·06; p=0·061), malaria infections (0·58; 0·46-0·72; p<0·0001), non-malarial infections (0·52; 0·46-0·58; p<0·0001), serious adverse events (0·42; 0·27-0·67; p<0·0001), and death (0·70; 0·25-1·97; p=0·50). Dose-limiting toxicity rates were similar between the fixed-dose (24·1 per 100 patient-years) and MTD phases (23·2 per 100 patient-years; 0·97; 0·70-1·35; p=0·86). Grade 3 and 4 adverse events were infrequent (18·5 per 100 patient-years) and included malaria infection, non-malarial infections, vaso-occlusive pain, and acute chest syndrome. Serious adverse events were uncommon (3·6 per 100 patient-years) and included malaria infections, parvovirus-associated anaemia, sepsis, and stroke, with no treatment-related deaths. INTERPRETATION: Hydroxyurea dose escalation to MTD with dose optimisation significantly improved clinical responses and treatment outcomes, without increasing toxicities in children with sickle cell anaemia in sub-Saharan Africa. FUNDING: US National Heart, Lung, and Blood Institute and Cincinnati Children's Research Foundation.

Understanding patient-related barriers to hydroxyurea use among adolescent and adult patients with sickle cell disease in Mulago and Kiruddu hospitals, Uganda, a qualitative study.

BACKGROUND: In 2016, Uganda added Hydroxyurea (HU) to the list of essential drugs to treat sickle cell disease SCD. However, Hydroxyurea utilization has been low for several countries in sub-Saharan Africa. This study examined patient-related barriers to hydroxyurea use among adolescent and adult patients with sickle cell disease in Mulago and Kiruddu hospitals, in Uganda. METHODS: To understand the patient-related barriers to hydroxyurea use among adolescent and adult patients with sickle cell disease, we conducted a parallel convergent mixed methods study at outpatient departments of two national referral hospitals in Uganda from October 2022 to January 2023. The cross-sectional mixed-methods study employed both quantitative and qualitative methods. We collected survey data from a systematic sample of 259 participants and conducted individual interviews with a purposive sample of 40 participants (20 adolescents or their caregivers and 20 adult patients with SCD) and interviewed them individually on their knowledge, perceptions, barriers, and facilitators of HU utilization. Descriptive data were analyzed using Stata 16, whereas qualitative data were analyzed thematically using an inductive approach supported by NVivo 12 software. We triangulated data to determine the concordance of qualitative and quantitative data. RESULTS: The study enrolled 40 participants for qualitative interviews and 259 patients for quantitative, with an average age of 16, over half being female, 46% having secondary education, and 96% unmarried. The prevalence of HU use was 78%. The study identified three themes as follows: Patient barriers at the individual including Inadequate knowledge about HU, Persistent pain, Poor adherence to HU, Poor communication with health care workers, and Psychosocial and emotional challenges. At the facility level, long queues and poor quality of care, drug-related side effects that affect HU, and drug stock-outs were reported. Myths, rumors, and misconceptions about HU, and gender-related barriers were reported to affect HU utilization at a community level. Facilitators for the use of HU and recommendations for improvement. Facilitators included perceived benefits, long duration on HU, information sharing by healthcare workers, availability of complementary drugs, confirmation of diagnosis, and availability of medication at public health facilities or private pharmacies. Patients suggested continuous adherence support, encouragement from healthcare workers, sensitization about benefits and risks, a peer-to-peer approach, and financial support for adolescents and women to start businesses to resolve financial problems. CONCLUSION: Implementing the use of HU has been challenging in Uganda and needs improvement. Facilitators to hydroxyurea use have been highlighted, though Patient-identified barriers at individual, facility, and community levels that need to be resolved. The experiences and insights shared by our participants provide invaluable guidance for increasing the uptake of HU. Further studies are needed to establish validated instruments to assess patients' pain communication and adherence to the HU regimen.

High throughput screening aids clinical decision-making in refractory acute myeloid leukaemia.

BACKGROUND: Despite advances in therapeutics for adverse-risk acute myeloid leukaemia (AML), overall survival remains poor, especially in refractory disease. Comprehensive tumour profiling and pre-clinical drug testing can identify effective personalised therapies. CASE: We describe a case of ETV6-MECOM fusion-positive refractory AML, where molecular analysis and in vitro high throughput drug screening identified a tolerable, novel targeted therapy and provided rationale for avoiding what could have been a toxic treatment regimen. Ruxolitinib combined with hydroxyurea led to disease control and enhanced quality-of-life in a patient unsuitable for intensified chemotherapy or allogeneic stem cell transplantation. CONCLUSION: This case report demonstrates the feasibility and role of combination pre-clinical high throughput screening to aid decision making in high-risk leukaemia. It also demonstrates the role a JAK1/2 inhibitor can have in the palliative setting in select patients with AML.

Cytoreductive therapy in younger adults with polycythemia vera: a meta-analysis of safety and outcomes.

ABSTRACT: Cytoreductive therapy is not routinely recommended for younger patients with polycythemia vera (PV) due to concern that treatment toxicity may outweigh therapeutic benefits. However, no systematic data support this approach. To support objective risk/benefit assessment of cytoreductive drugs in patients with PV aged <60 years (PV<60), this systematic review and meta-analysis was conducted to evaluate toxicity and disease-related complications in PV<60 treated with interferon alfa (rIFN-α) or hydroxyurea (HU). A search of PubMed, Scopus, Web of Science and Embase identified 693 unique studies with relevant keywords, of which 14 met inclusion criteria and were selected for analysis. The weighted average age of patients treated with rIFN-α was 48 years (n = 744 patients; 12 studies) and for HU was 56 years (n = 1397; 8 studies). The weighted average duration of treatment for either drug was 4.5 years. Using a Bayesian hierarchical model, the pooled annual rate of discontinuation due to toxicity was 5.2% for patients receiving rIFN-α (n = 587; 95% confidence interval [CI], 2.2-8.2) and 3.6% for HU (n = 1097; CI, 1-6.2). The average complete hematologic response for rIFN-α and HU was 62% and 52%, respectively. Patients experienced thrombotic events at a pooled annual rate of 0.79% and 1.26%; secondary myelofibrosis at 1.06% and 1.62%; acute myeloid leukemia at 0.14% and 0.26%; and death at 0.87% and 2.65%, respectively. No treatment-related deaths were reported. With acceptable rates of nonfatal toxicity, cytoreductive treatment, particularly with disease-modifying rIFN-α, may benefit PV<60. Future randomized trials prioritizing inclusion of PV<60 are needed to establish a long-term benefit of early cytoreductive treatment in these patients.

Prevalence of Duffy null and its impact on hydroxyurea in young children with sickle cell disease in the United States.

Consistent with studies showing a high prevalence of the Duffy null phenotype among healthy Black Americans, this retrospective study found that Duffy null was present in >75% of a young and contemporary cohort of children with sickle cell disease (SCD) in the United States. Despite the potential for this phenotype to impact absolute neutrophil counts, hydroxyurea (HU) dosing, and outcomes, it was not associated with being prescribed a lower HU dose or having increased acute SCD visits early in the HU treatment course. Future studies are needed to confirm these findings in older children with SCD.

Systemic medications for sickle cell disease and potential applications for sickle cell retinopathy.

PURPOSE OF REVIEW: To review the literature evaluating systemic medications for treatment of sickle cell disease (SCD) and their applications for sickle cell retinopathy. RECENT FINDINGS: Prior studies have demonstrated the efficacy of traditional systemic therapies in reducing the risk of development of sickle cell retinopathy. Since 2017, several new and promising disease-modifying therapies for sickle cell disease have been approved for clinical use, including the first genetic therapies such as exagamglogene autotemcel (exa-cel) and lovotibeglogene autotemcel (lovo-cel). These treatments have shown promising results for systemic management but are not widely utilized due to limited access and high cost. The efficacy of these therapies for the prevention of sickle cell retinopathy remains unknown and opens the door to new avenues for research. Furthermore, the role of systemic therapy for the management of hemoglobin SC (HbSC) disease, which has milder systemic effects but higher likelihood of causing retinopathy, remains poorly understood. SUMMARY: Hydroxyurea has been a mainstay of systemic management of SCD with prior work suggesting its ability to reduce the likelihood of developing retinopathy. There are several new and potentially curative systemic therapies for SCD, though their role in retinopathy prevention and management has not been studied extensively. Future studies are necessary to understand the implications of these emerging therapies for sickle cell retinopathy.

Hydroxyurea Adherence for Personal Best in Sickle Cell Treatment (HABIT) efficacy trial: Community health worker support may increase hydroxyurea adherence of youth with sickle cell disease.

Despite disease-modifying effects of hydroxyurea on sickle cell disease (SCD), poor adherence among affected youth commonly impedes treatment impact. Following our prior feasibility trial, the "Hydroxyurea Adherence for Personal Best in Sickle Cell Treatment (HABIT)" multi-site randomized controlled efficacy trial aimed to increase hydroxyurea adherence for youth with SCD ages 10-18 years. Impaired adherence was identified primarily through flagging hydroxyurea-induced fetal hemoglobin (HbF) levels compared to prior highest treatment-related HbF. Eligible youth were enrolled as dyads with their primary caregivers for the 1-year trial. This novel semi-structured supportive, multidimensional dyad intervention led by community health workers (CHW), was augmented by daily tailored text message reminders, compared to standard care during a 6-month intervention phase, followed by a 6-month sustainability phase. Primary outcomes from the intervention phase were improved Month 6 HbF levels compared to enrollment and proportion of days covered (PDC) for hydroxyurea versus pre-trial year. The secondary outcome was sustainability of changes up to Month 12. The 2020-2021 peak coronavirus disease 2019 (COVID-19) pandemic disrupted enrollment and clinic-based procedures; CHW in-person visits shifted to virtual scheduled interactions. We enrolled 50 dyads, missing target enrollment. Compared to enrollment levels, both HbF level and PDC significantly - but not sustainably - improved within the intervention group (p = .03 and .01, respectively) with parallel increased mean corpuscular volume (MCV) (p = .05), but not within controls. No significant between-group differences were found at Months 6 or 12. These findings suggest that our community-based, multimodal support for youth-caregiver dyads had temporarily improved hydroxyurea usage. Durability of impact should be tested in a trial with longer duration of CHW-led and mobile health support.

Reducing transfusion utilization for children with sickle cell anemia in sub-Saharan Africa with hydroxyurea: Analysis from the phase I/II REACH trial.

Children with sickle cell anemia (SCA) in Africa frequently require transfusions for SCA complications. Despite limited blood supplies, strategies to reduce their transfusion needs have not been widely evaluated or implemented. We analyzed transfusion utilization in children with SCA before and during hydroxyurea treatment. REACH (Realizing Effectiveness Across Continents with Hydroxyurea, NCT01966731) is a longitudinal Phase I/II trial of hydroxyurea in children with SCA from Angola, Democratic Republic of Congo, Kenya, and Uganda. After enrollment, children had a two-month pre-treatment screening period followed by 6 months of fixed-dose hydroxyurea (15-20 mg/kg/day), 18 months of dose escalation, and then stable dosing at maximum tolerated dose (MTD). Characteristics associated with transfusions were analyzed with univariate and multivariable models. Transfusion incidence rate ratios (IRR) across treatment periods were calculated. Among 635 enrolled children with 4124 person-years of observation, 258 participants (40.4%) received 545 transfusions. The transfusion rate per 100 person-years was 43.2 before hydroxyurea, 21.7 on fixed-dose, 14.5 during dose escalation, and 10.8 on MTD. During MTD, transfusion incidence was reduced by 75% compared to pre-treatment (IRR 0.25, 95% confidence interval [CI] 0.18-0.35, p < .0001), and by 50% compared to fixed dose (IRR 0.50, 95% CI 0.39-0.63, p < .0001). Hydroxyurea at MTD decreases transfusion utilization in African children with SCA. If widely implemented, universal testing and hydroxyurea treatment at MTD could potentially prevent 21% of all pediatric transfusions administered in sub-Saharan Africa. Increasing hydroxyurea access for SCA should decrease the transfusion burden and increase the overall blood supply.

Disease-Modifying Therapies for Sickle Cell Disease-An Overview.

Sickle cell disease refers to a group of inherited blood disorders in which hemoglobin polymerization leads to hemolysis and vaso-occlusion. This causes a myriad of complications during a patient's life span, ranging from anemia, infections, and acute and chronic pain to stroke and multiorgan dysfunction. Although there have been dramatic improvements in childhood survival thanks to improved supportive care with penicillin prophylaxis, immunizations, and improved transfusion practices, there was a dearth of disease-modifying therapies, with hydroxyurea being the only medication for >20 years. Here, we discuss the newer therapies for sickle cell disease that have emerged in recent years. [Pediatr Ann. 2024;53(2):e52-e55.].

Role of hydroxyurea therapy in the prevention of organ damage in sickle cell disease: a systematic review and meta-analysis.

BACKGROUND: Hydroxyurea is an affordable drug that reduces vaso-occlusive crises and transfusion requirements in sickle cell disease. However, its effectiveness in preventing chronic organ damage is still unclear. This systematic review and meta-analysis aimed to evaluate the role of hydroxyurea in preventing organ morbidity. METHOD: We included original articles published in English from 1st January 1990 to 31st January 2023, reporting hydroxyurea therapy and organ damage from PubMed, Google Scholar, Scopus, and CrossRef databases. A total of 45 studies with 4681 sickle cell disease patients were evaluated for organ damage. RESULTS: Our analysis showed that hydroxyurea intervention significantly lowered transcranial Doppler and tricuspid regurgitant velocity, with a standardized mean difference of - 1.03 (- 1.49; - 0.58); I 2 = 96% and - 1.37 (CI - 2.31, - 0.42); I 2 = 94%, respectively. Moreover, the pooled estimate for albuminuria showed a beneficial effect post-hydroxyurea therapy by reducing the risk of albuminuria by 58% (risk ratio of 0.42 (0.28; 0.63); I 2 = 28%). CONCLUSION: Our study found that a hydroxyurea dose above 20 mg/kg/day with a mean rise in HbF by 18.46% post-hydroxyurea therapy had a beneficial role in reducing transcranial doppler velocity, tricuspid regurgitant velocity, albuminuria, and splenic abnormality. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42023401187.

An update review of new therapies in sickle cell disease: the prospects for drug combinations.

INTRODUCTION: Sickle cell disease (SCD) is an inherited disorder characterised by polymerisation of deoxygenated haemoglobin S and microvascular obstruction. The cardinal feature is generalised pain referred to as vaso-occlusive crises (VOC), multi-organ damage and premature death. SCD is the most prevalent inherited life-threatening disorders in the world and over 85% of world's 400,000 annual births occur low-and-middle-income countries. Hydroxyurea remained the only approved disease modifying therapy (1998) until the FDA approved L-glutamine (2017), Crizanlizumab and Voxelotor (2019) and gene therapies (Exa-cel and Lovo-cel, 2023). AREAS COVERED: Clinical trials performed in the last 10 years (November 2013 - November 2023) were selected for the review. They were divided according to the mechanisms of drug action. The following pubmed central search terms [sickle cell disease] or [sickle cell anaemia] Hydroxycarbamide/ Hydroxyurea, L-Glutamine, Voxelotor, Crizanlizumab, Mitapivat, Etavopivat, gene therapy, haematopoietic stem cell transplantation, and combination therapy. EXPERT OPINION: We recommend future trials of combination therapies for specific complications such as VOCs, chronic pain and renal impairment as well as personalised medicine approach based on phenotype and patient characteristics. Following recent approval of gene therapy for SCD, the challenge is addressing the role of shared decision-making with families, global access and affordability.

Hidroxiureia para o tratamento de pacientes com doença falciforme (SS, Sbeta0 e SD Punjab), entre 9 e 24 meses de idade, sem sintomas e complicações / Hydroxyureia for the treatment of patients with sickle cell disease (SS, Sbeta0 and SD Punjab), between 9 and 24 months of age, without symptoms and complications

INTRODUÇÃO: As manifestações clínicas da doença falciforme (DF) estão relacionadas à anemia hemolítica e aos efeitos da falcização intravascular repetida, resultando em vasooclusão e lesão isquêmica, além de morbidade e mortalidade consideráveis em idade precoce. Atualmente, a hidroxiureia é o padrão de tratamento para prevenir crises de dor vasoclusivas na DF, sendo recomendada para crianças entre 9 e 24 meses de idade, quando apresentam determinados sintomas ou complicações. Considerando que o uso precoce desta tecnologia (antes de 2 anos de idade) pode evitar o comprometimento a longo prazo relacionados à evolução da DF, o objetivo do presente relatório é analisar as evidências científicas sobre eficácia, efetividade, segurança, bem como evidências econômicas relacionadas ao uso de hidroxiureia para o tratamento de indivíduos com doença falciforme (SS, Sbeta0 e SD Punjab) entre 9 e 24 meses de idade, independentemente de sintomas e complicações. PERGUNTA: O uso de h

"In-silico Design and Development of Novel Hydroxyurea Lipid Drug Conjugates for Breast Cancer Therapy Targeting PI3K/AKT/mTOR Pathway".

Hydroxyurea (HU) has shown promise in breast cancer treatment, but its hydrophilic nature limits its efficacy. Therefore, conjugating HU with lipids could increase its liphophilicity and improve its cellular uptake, leading to increased efficacy and reduced toxicity. The PI3K/Akt/mTOR pathway is an attractive therapeutic target in cancer not only because it is the second most frequently altered pathway after p53, but also because it serves as a convergence point for many stimuli. The aim of this study is to design and develop novel hydroxyurea lipid drug conjugates for breast cancer therapy targeting the PI3K/Akt/mTOR pathway using in-silico and in-vitro approaches. The conjugates are designed and docked with the proteins selected for each target like PI3K (PDB ID;2JDO), AKT (PDB ID;3APF), mTOR (PDB ID;4JST). The conjugates with higher docking scores are taken for ADME studies and molecular dynamics. Stearic, lauric, palmitic, myristic and linolenic acids have been used for the conjugation. The conjugates are synthesized and characterized. The HLB calculation and partition coefficient are carried out to find the improvement in liphophilicity of the conjugates compared to hydroxyurea. Finally, the in-vitro cytotoxicity studies are performed with MCF -7 cell lines and the compound HU-MA (hydroxyurea with myristic acid) with low IC50 is considered as the compound having good activity with compound code. These conjugates have been shown to have improved drug solubility and better cellular uptake compared to free hydroxyurea, which can increase drug efficacy.

Managing sickle cell disease and related complications in pregnancy: results of an international Delphi panel.

ABSTRACT: Data to guide evidence-based management of pregnant people with sickle cell disease (SCD) are limited. This international Delphi panel aimed to identify consensus among multidisciplinary experts for SCD management during pregnancy. The 2-round Delphi process used questionnaires exploring 7 topics (antenatal care, hydroxyurea use, transfusion, prevention of complications, treatment of complications, delivery and follow-up, and bottlenecks and knowledge gaps) developed by a steering committee. Thirteen panelists (hematologists, physiologists, obstetricians, maternal fetal medicine, and transfusion medicine physicians) from the United States, the United Kingdom, Turkey, and France completed the first survey; 12 panelists completed the second round. Anonymized responses were collected and summarized by a contract research organization (Akkodis Belgium). Consensus and strong consensus were predefined as 75% to 90% (9-10 of 12) and >90% (≥11 of 12) of panelists, respectively, agreeing or disagreeing on a response to a predefined clinical scenario or statement. In several areas of SCD management, consensus was achieved: experts recommended performing at least monthly multidisciplinary antenatal follow-up, administering prophylactic aspirin for preeclampsia prevention between gestational weeks 12 and 36, initiating prophylactic transfusion therapy in certain cases, or choosing automated red blood cell exchange over other transfusion methods for patients with iron overload or severe acute chest syndrome. No consensus was reached on several topics including the prophylactic aspirin dose, indications for starting infection prophylaxis, routine use of prophylactic transfusions, or use of prophylactic transfusions for preventing fetal complications. These recommendations could inform clinical care for patients with SCD who are pregnant in the absence of large clinical trials involving this population; the identified knowledge gaps can orient future research.

Hydroxyurea is associated with later onset of acute splenic sequestration crisis in sickle cell disease: Lessons from the European Sickle Cell Disease Cohort-Hydroxyurea (ESCORT-HU) study.

Acute splenic sequestration crisis (ASSC) is a potentially life-threatening complication of sickle cell disease (SCD), typically occurring in young patients under 5 years of age, with a median age at first episode of less than 2 years. Because a beneficial effect of hydroxyurea (HU) on spleen perfusion and splenic function has been suspected, we hypothesized that HU treatment might be associated with later onset of ASSC in patients with SCD. To investigate this hypothesis, we analyzed data from the ESCORT-HU study on a large cohort of patients with SCD receiving HU, enrolled between January 2009 and June 2017 with a follow-up of 7309 patient-years of observation. The median age at ASSC of the 14 patients who experienced a first episode of ASSC during the study period was 8.0 [IQR: 5.0-24.1] years. The median age at HU initiation was significantly lower in these 14 patients (4.8 [IQR: 3.3-18.7] years) compared to the 1664 patients without ASSC (19.9 [8.8-33.4] years, p = .0008). These findings suggest that ASSC may occur at an unusually late age in patients receiving HU, possibly reflecting longer preservation of spleen perfusion and function secondary to early initiation of HU. Further studies are needed to better characterize the effects of HU on spleen perfusion/function and on the occurrence of ASSC in patients with SCD (ClinicalTrials.gov identifier: NCT02516579; European registry ENCEPP/SDPP/10565).

Hydroxyurea reduces infections in children with sickle cell anemia in Uganda.

ABSTRACT: After starting hydroxyurea treatment, Ugandan children with sickle cell anemia had 60% fewer severe or invasive infections, including malaria, bacteremia, respiratory tract infections, and gastroenteritis, than before starting hydroxyurea treatment (incidence rate ratio, 0.40 [95% confidence interval, 0.29-0.54]; P < .001).