Please select the eligibility criteria that correspond to the clinical trial below.
Title: TCD With Transfusions Changing to Hydroxyurea (TWiTCH): A Phase III Randomized Trial to Compare Standard Therapy (Erythrocyte Transfusions) With Alternative Therapy (Hydroxyurea) for the Maintenance of Lowered TCD Velocities in Pediatric Subjects With Sickle Cell Anemia and Abnormal Pre-treatment TCD Velocities
Brief Summary: The primary goal of the Phase III TWiTCH trial is to compare 24 months of alternative therapy (hydroxyurea) to standard therapy (transfusions) for pediatric subjects with sickle cell anemia and abnormally high (≥200 cm/sec) Transcranial Doppler (TCD) velocities, who currently receive chronic transfusions to reduce the risk of primary stroke. For the alternative treatment regimen (hydroxyurea) to be declared non-inferior to the standard treatment regimen (transfusions), after adjusting for baseline differences, the hydroxyurea-treated group must have a mean TCD velocity similar to that observed with transfusion prophylaxis.


Options:
A: Inclusion Criteria:

* Diagnosis of sickle cell anemia (HbSS, HbSD, HbS/β0-thalassemia, or similarly severe SCA genotype)
* Age 6 months to 21 years at the time of enrollment
* Clinical decision by patient, family, and healthcare providers to initiate hydroxyurea therapy

Exclusion Criteria:

* Current treatment with chronic, monthly blood transfusions or erythrocytapheresis
* Treatment with hydroxyurea within the past 3 months
* Hemoglobin SC disease, HbS/β+-thalassemia
* Current treatment with other investigational sickle cell medications
* Current known pregnancy or lactation
B: Inclusion Criteria:

* Male and female subjects with a confirmed diagnosis of sickle cell disease (HbSS or HBS-β0 thalassemia) between the ages of 18 and 65 years, inclusive
* Subjects who are being treated with hydroxyurea must be on a stable dose for at least 8 weeks, with the intent of remaining on the same dose of hydroxyurea throughout the clinical trial including the protocol-specified follow-up period. Subjects who are not treated with hydroxyurea should not plan to begin treatment during the study period.
* Body Mass Index (BMI) of 17.5 to 35 kg/m2; and a total body weight \>40 kg (88 lbs

Exclusion Criteria:

* History of a recent major surgery, within 3 months of baseline visit.
* Serious infection (requiring hospitalization or parenteral antibiotics) within 1 month of baseline visit.
* History of cerebrovascular accident or seizure disorder.
* Subjects with a history of clinically significant orthostatic blood pressure (BP) changes or clinically significant orthostatic symptoms.
* Known previous diagnosis of acute hepatitis of any aetiology Hepatitis B or C or Human immunodeficiency virus (HIV) infection.
* History of any malignancy except for subjects who had a basal or squamous cell cancer which has been treated and fully resolved for a minimum of 5 years.
* History or evidence of cardiac disease including: myocardial infarction, cardiac arrhythmia
* Systemic therapy with any of the following medications that are strong or moderate CYP3A4 inhibitors within 7 days or 5 half-lives (whichever is longer) or CYP3A inducers within 28 days prior to the first dose of the trial medication, or during the trial.
* Use of PDE5 inhibitors within 7 days prior to the first dose of the trial medication, or at any time during the trial.
* Creatinine clearance \<30ml/min.
* Hemoglobin level \<6 gm/dL.
* Alanine transaminase (ALT/SGPT) and Aspartate aminotransferase (AST/SGOT) \>2x upper limit of normal, (based on clinic laboratory normal range).
* Any condition possibly affecting drug absorption (eg, gastrectomy).
* A positive urine drug screen for illicit drug.
* History of regular alcohol consumption exceeding 14 drinks/week for females or 21 drinks/week for males (1 drink = 5 ounces (150 mL) of wine or 12 ounces (360 mL) of beer or 1.5 ounces (45 mL) of hard liquor) within 6 months of Screening.
* Treatment with an investigational drug within 2 months (or as determined by the local requirement, whichever is longer) or 5 half-lives preceding the first dose of study medication.
* 12-lead ECG demonstrating QTc \>450 or a QRS interval \>120 msec msec at Screening.
* Other severe acute or chronic medical or psychiatric condition or laboratory abnormality that may increase the risk associated with study participation or investigational product administration or may interfere with the interpretation of study results and, in the judgment of the investigator, would make the subject inappropriate for entry into this study.
* A family history of long QT syndrome and/or ECG abnormalities at screening or randomization, including those listed below:

  * Subjects with pre-randomization evidence of QTcF prolongation (defined as \>450 ms) at screening or baseline are not eligible for randomization.
  * Predominant heart rhythm other than normal sinus rhythm eg, atrial fibrillation, atrial flutter, supraventricular tachycardia.
  * Atrioventricular (AV) block greater than first degree.
* Use of concomitant medications that prolong the QT/QTc interval
* Pregnant females and, breast feeding females and females of childbearing potential; male and female subjects of childbearing potential who are unwilling or unable to use highly effective methods of contraception as outlined in this protocol for the duration of the study and for at least 30 days after the last dose of investigational product.
* Subjects who lack the capacity to consent for themselves.
C: Inclusion Criteria:

1. Pediatric subjects with severe forms of sickle cell anemia (HbSS, HbSβ0 thalassemia,HbSOArab)
2. Age range of 4.0-15.99 years, inclusive, at the time of enrollment
3. Documented index (pre-treatment) abnormally high TCD Velocity by Transcranial Doppler ultrasonography. An abnormally high index TCD is defined as TCD V greater than or equal to 200 cm/sec, or abnormally high TCDi V greater than or equal to185cm/sec, or TCD maximum V greater than or equal to 250 cm/sec.
4. At least 12 months of chronic monthly erythrocyte transfusions since the index abnormal TCD examination
5. Adequate monthly erythrocyte transfusions with average HbS less than or equal to 45% (the upper limit of the established academic community standard) for the past 6 months before enrollment
6. Parent or guardian willing and able to provide informed consent with verbal or written assent from the child
7. Ability to comply with study related treatments, evaluations, and follow-up

Exclusion Criteria:

1. Completed overt clinical stroke or TIA
2. Inability to obtain TCD velocities due to anatomical abnormalities such as a) Inadequate bone windows b) Previous revascularization procedures (e.g., EDAS)
3. Known severe vasculopathy or moya-moya disease on brain MRA
4. Inability to receive or tolerate chronic red blood cell (RBC) transfusion therapy, due to any of the following: a) Multiple RBC alloantibodies making cross-matching difficult or impossible b) RBC autoantibodies making cross-matching difficult or impossible c) Religious objection to transfusions that preclude their chronic use d) Non-compliance with transfusions over the past 6 months before enrollment (temporary exclusion)
5. Inability to take or tolerate daily oral hydroxyurea, including a) Known allergy to hydroxyurea therapy b) Positive serology to HIV infection c) Malignancy d) Current lactation e) Previous stem cell transplant or other myelosuppressive therapy
6. Clinical and laboratory evidence of hypersplenism (temporary exclusions): a) Palpable splenomegaly greater than 5cm below the left costal margin AND b) Transfusion requirement greater than 250 mL/kg over the previous 12 months
7. Abnormal laboratory values at initial evaluation (temporary exclusions): a) Pre-transfusion hemoglobin concentration less than 8.0 gm/dL b) WBC count less than 3.0 x 10\^9/L c) Absolute neutrophil count (ANC) less than 1.5 x 10\^9/L d) Platelet count less than 100 x 10\^9/L e) Serum creatinine more than twice the upper limit for age OR greater than or equal to 1.0 mg/dL
8. Current participation in other therapeutic clinical trials
9. Current use of other therapeutic agents for sickle cell disease (e.g., arginine, decitabine, magnesium). Subjects must have been off hydroxyurea for at least 3- months prior to enrollment.
10. Any condition or chronic illness, such as a positive tuberculin (PPD) test, which in the opinion of the CI makes participation ill-advised.
11. Inability or unwillingness to complete required screening and exit studies, including TCD ultrasonography, brain MRI/MRA, liver MRI and blood tests.
12. A sibling enrolled in TWiTCH
13. Pregnancy or unwillingness to use a medically acceptable form of contraception if sexually active (male OR female).
D: Inclusion Criteria:

* Children with confirmed SCA who participated in the NOHARM study of hydroxyurea at the Mulago Hospital Sickle Cell Clinic (MHSCC), will be eligible for the MTD study after completing both 12-months of blinded study treatment and then an additional 12-months of open-label hydroxyurea for the second year of the study.
* The age range for enrollment into NOHARM, which began in 2014, was 1-4 years. Therefore, the children who will be enrolled in the follow up MTD study will be 3-6 years of age.

Exclusion Criteria:

* Not willing to come for all scheduled clinical visits or accept randomization

Answer: C