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Treatment of Hemoglobin SC Disease With Hydroxyurea

SC Youth Treatment With Hydroxyurea Effects

Status
Terminated
Phases
Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT02336373
Acronym
SCYTHE
Enrollment
32
Registered
2015-01-13
Start date
2014-12-31
Completion date
2017-03-31
Last updated
2020-09-09

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Hemoglobin SC Disease

Keywords

Hemoglobin SC disease, hydroxyurea, quality of life, viscosity, red cell density

Brief summary

Sickle cell disease (SCD), specifically hemoglobin SC disease (HbSC), is a subtype of sickle cell disease with typically higher hemoglobin and milder or later disease complications. Sickle cell disease is a disorder in which red blood cells (RBCs) are abnormally shaped. This can result in painful episodes, serious infections, and damage to body organs. One medication used to treat sickle cell disease is hydroxyurea. Hydroxyurea therapy offers significant benefits for infants, children, and adolescents with sickle cell anemia. These include a reduction in the frequency of pain crises and acute chest syndrome (inflammation of the lungs). Hydroxyurea has been given to many HbSC patients but HbSC patients were not included in the large clinical trials used to test hydroxyurea in SCD, so less is known about how HbSC patients respond to hydroxyurea. The purpose of this research study is to see if hydroxyurea, a medication given to many children with the most common type of sickle cell, those who are homozygous for the sickle mutation (HbSS), helps children who have HbSC. The investigators will see if it helps by giving a questionaire when the medication is started, and then every two months at a clinic visit. The questionaire, called the Pediatric Quality of Life Inventory (PedsQL™) Sickle Cell Disease Module version 3.0, measures quality of life. The investigators will also see how hydroxyurea changes laboratory test numbers, and blood thickness.

Detailed description

To be eligible to participate in this study, patients must have HbSC disease, have experienced a sickle cell disease related complication, or have a score of 80 or lower on the PedsQL™ Sickle Cell Disease Module version 3.0. This questionnaire will be offered to all patients with HbSC seen in our clinic that consent to this study. If the patient is sexually active, they will be offered birth control. If the patient chooses not to initiate effective birth control, they will be tested at their scheduled vist with a urine pregnancy test. If the patient becomes pregnant they will be removed from the study. The maximum time patients will be on the study is 12 months after starting hydroxyurea therapy, with an option to participate in a 2 year observation study following the end of the study. Patients will be assessed in the clinic every two months after starting treatment. Hydroxyurea will be started at 10 mg/kg/day, and increased by 5 mg/kg/day at eight week intervals if needed to reach a maximum tolerated dose (MTD). The most common side effect of the drug is a drop in infection fighting cells, or white blood cells, so the medication will be started at a low dose and the dose will be increased only if it is safe to do so. Patients will be asked to allow the investigators to review information from their medical records at the start of the study, and throughout the study. If the patient would like to participate in the two year follow-up, their records will be reviewed during that period as well.

Interventions

DRUGhydroxyurea

Treat symptomatic HbSC patients to MTD on hydroxyurea, and assess for clinical improvement using the PedsQL™ Sickle Cell Disease Module version 3.0 after 6 months at MTD, compared to entrance scores

Sponsors

Baylor College of Medicine
Lead SponsorOTHER

Study design

Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
5 Years to 21 Years
Healthy volunteers
No

Inclusion criteria

1. Diagnosis of HbSC disease 2. Score equal or lower than 80 on the PedsQL™ Sickle Cell Disease Module version 3.0 3. Have experienced a sickle cell disease related complication

Exclusion criteria

1. Failure to meet inclusion criteria. 2. Hydroxyurea usage in the last 3 months. 3. Chronic RBC transfusion therapy. 4. Packed red blood cell transfusion in the last 3 months (temporary exclusion). 5. Pregnancy, or refusal to use medically effective birth control if female and sexually active.

Design outcomes

Primary

MeasureTime frameDescription
Change in PedsQL SCDM6 monthsMean change in PedsQL™ Sickle Cell Disease Module version 3.0 score after achieving MTD compared with baseline. PedsQL™ Sickle Cell Disease Module version 3.0 scores are on a 100 point scale ranging from 0 to 100 with higher values indicating better quality of life. PedsQL: pediatric qulaity of life

Secondary

MeasureTime frameDescription
Change in HVR at 225s-1up to 7 monthsChange in hematocrit viscosity ratio at 225s
DRBCup to 7 monthsChange in percent dense red blood cells
Change in HbFup to 7 monthsChange in fetal hemaglobin
Change in MCVup to 7 monthsChange in mean corpuscular volume
Change in MCHCup to 7 monthsChange in mean corpuscular hemoglobin concentration
Change in HVR at 45s-1up to 7 monthsChange in hematocrit to viscosity ratio (HVR) at 45s-1 at follow-up versus baseline. This is a measure of oxygen carrying capacity, as a higher hematocrit with lower viscosity indicates ability to deliver oxygen without slowed blood flow due to high viscosity or blood thickness. Higher values are associated with improvement.
Change in ARCup to 7 monthsChange in absolute reticulocyte count
Change in ANCup to 7 monthsChange in absolute neutrophil count
Change in LDHup to 7 monthsChange in lactate dehydrogenase
Change in UB Levelsup to 7 monthsChange in unconjugated bilirubin levels
Change in Hbup to 7 monthsChange in hemoglobin

Countries

United States

Participant flow

Participants by arm

ArmCount
Hydroxyurea
hydroxyurea (HU) at 10 mg/kg daily
32
Total32

Withdrawals & dropouts

PeriodReasonFG000
Overall StudyPhysician Decision14
Overall StudyProtocol closed early4

Baseline characteristics

CharacteristicHydroxyurea
Age, Categorical
<=18 years
32 Participants
Age, Categorical
>=65 years
0 Participants
Age, Categorical
Between 18 and 65 years
0 Participants
Age, Continuous11 years
STANDARD_DEVIATION 3.5
Ethnicity (NIH/OMB)
Hispanic or Latino
1 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
31 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
0 Participants
PedsQLTM 3.0 SCD Module score54.9 units on a scale
STANDARD_DEVIATION 20.4
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants
Race (NIH/OMB)
Asian
0 Participants
Race (NIH/OMB)
Black or African American
31 Participants
Race (NIH/OMB)
More than one race
1 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants
Race (NIH/OMB)
Unknown or Not Reported
0 Participants
Race (NIH/OMB)
White
0 Participants
Region of Enrollment
United States
32 participants
Sex: Female, Male
Female
13 Participants
Sex: Female, Male
Male
19 Participants

Adverse events

Event typeEG000
affected / at risk
deaths
Total, all-cause mortality
0 / 32
other
Total, other adverse events
0 / 32
serious
Total, serious adverse events
0 / 32

Outcome results

Primary

Change in PedsQL SCDM

Mean change in PedsQL™ Sickle Cell Disease Module version 3.0 score after achieving MTD compared with baseline. PedsQL™ Sickle Cell Disease Module version 3.0 scores are on a 100 point scale ranging from 0 to 100 with higher values indicating better quality of life. PedsQL: pediatric qulaity of life

Time frame: 6 months

Population: Participants who achieved MTD of hydroxyureq per protocol with observed PEDSQL scores at 6-months and baseline (study entry).

ArmMeasureValue (MEAN)Dispersion
HydroxureaChange in PedsQL SCDM5.7 Score on PedsQL 3.0 SCD ModuleStandard Deviation 15.5
Secondary

Change in ANC

Change in absolute neutrophil count

Time frame: up to 7 months

ArmMeasureValue (MEAN)Dispersion
HydroxureaChange in ANC-0.24 10^3 cells/uLStandard Deviation 0.82
Secondary

Change in ARC

Change in absolute reticulocyte count

Time frame: up to 7 months

ArmMeasureValue (MEAN)Dispersion
HydroxureaChange in ARC0.01 10^3 cells/uLStandard Deviation 0.025
Secondary

Change in Hb

Change in hemoglobin

Time frame: up to 7 months

ArmMeasureValue (MEAN)Dispersion
HydroxureaChange in Hb-0.62 percentStandard Deviation 0.59
Secondary

Change in HbF

Change in fetal hemaglobin

Time frame: up to 7 months

ArmMeasureValue (MEAN)Dispersion
HydroxureaChange in HbF-0.47 percentStandard Deviation 0.94
Secondary

Change in HVR at 225s-1

Change in hematocrit viscosity ratio at 225s

Time frame: up to 7 months

ArmMeasureValue (MEAN)Dispersion
HydroxureaChange in HVR at 225s-10.11 auStandard Deviation 0.83
Secondary

Change in HVR at 45s-1

Change in hematocrit to viscosity ratio (HVR) at 45s-1 at follow-up versus baseline. This is a measure of oxygen carrying capacity, as a higher hematocrit with lower viscosity indicates ability to deliver oxygen without slowed blood flow due to high viscosity or blood thickness. Higher values are associated with improvement.

Time frame: up to 7 months

ArmMeasureValue (MEAN)Dispersion
HydroxureaChange in HVR at 45s-10.083 auStandard Deviation 0.72
Secondary

Change in LDH

Change in lactate dehydrogenase

Time frame: up to 7 months

ArmMeasureValue (MEAN)Dispersion
HydroxureaChange in LDH-21.7 percentStandard Deviation 52.48
Secondary

Change in MCHC

Change in mean corpuscular hemoglobin concentration

Time frame: up to 7 months

ArmMeasureValue (MEAN)Dispersion
HydroxureaChange in MCHC0.33 percentStandard Deviation 0.43
Secondary

Change in MCV

Change in mean corpuscular volume

Time frame: up to 7 months

ArmMeasureValue (MEAN)Dispersion
HydroxureaChange in MCV-6.2 fLStandard Deviation 2.3
Secondary

Change in UB Levels

Change in unconjugated bilirubin levels

Time frame: up to 7 months

ArmMeasureValue (MEAN)Dispersion
HydroxureaChange in UB Levels-0.1 percentStandard Deviation 0.28
Secondary

DRBC

Change in percent dense red blood cells

Time frame: up to 7 months

ArmMeasureValue (MEAN)Dispersion
HydroxureaDRBC1.93 percentage of dense red blood cellsStandard Deviation 20.6

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026