Trial Outcomes & Findings for Long-Term Effects of Hydroxyurea in Children With Sickle Cell Anemia (The BABY HUG Follow-up Study) (NCT NCT00890396)
NCT ID: NCT00890396
Last Updated: 2020-08-20
Results Overview
The change in splenic function from the randomized control trial baseline measurement was one of the primary outcomes. The change in splenic function (worse vs not-worse) was compared between the randomized treatment groups (hydroxyurea vs placebo). The change in splenic function from baseline to 48 months was defined as worse if it changed from normal to decreased or absent, or decreased to absent; and not worse if it changed from decreased to decreased, normal to normal, decreased to normal, absent to absent, or absent to decreased.
COMPLETED
163 participants
48 Months from the date of randomization
2020-08-20
Participant Flow
Subjects that were eligible for enrollment included all children who have completed at least 18 months of the BABY HUG Treatment Study.
Parents and the participants' health care providers, who had not yet been informed of the BABY HUG randomized treatment, selected open label hydroxyurea (HU) treatment or standard care (SC).
Participant milestones
| Measure |
Active
An active follow-up involved the performance of many of the laboratory tests and procedures done during BABY HUG clinical trials study. These included, but not limited to, serial laboratory parameters that were not part of routine clinical care such as Hgb F levels, pitted cell count, Howell-Jolly Body determination, a liver-spleen scan, diethylenetriaminepentaacetic acid (DTPA) glomerular filtration rate (GFR) measurement, creatinine clearance, Cystatin C, urine concentrating ability, transcranial Doppler, and neuropsychological testing.
|
Passive
A passive follow-up involved the abstraction of clinical data from the medical record. Results of physical examinations and laboratory tests performed as part of routine clinical care were recorded.
|
|---|---|---|
|
Overall Study
STARTED
|
127
|
36
|
|
Overall Study
COMPLETED
|
122
|
34
|
|
Overall Study
NOT COMPLETED
|
5
|
2
|
Reasons for withdrawal
Withdrawal data not reported
Baseline Characteristics
Long-Term Effects of Hydroxyurea in Children With Sickle Cell Anemia (The BABY HUG Follow-up Study)
Baseline characteristics by cohort
| Measure |
Active
n=127 Participants
An active follow-up involved the performance of many of the laboratory tests and procedures done during BABY HUG clinical trials study. These included, but not limited to, serial laboratory parameters that were not part of routine clinical care such as Hgb F levels, pitted cell count, Howell-Jolly Body determination, a liver-spleen scan, DTPA GFR measurement, creatinine clearance, Cystatin C, urine concentrating ability, transcranial Doppler, and neuropsychological testing. Patients could be on or off hydroxyurea at the start of Follow-Up Study I, and could change treatment during the study.
|
Passive
n=36 Participants
A passive follow-up involved the abstraction of clinical data from the medical record. Results of physical examinations and laboratory tests performed as part of routine clinical care were recorded. Patients could be on or off hydroxyurea at the start of Follow-Up Study I, and could change treatment during the study.
|
Total
n=163 Participants
Total of all reporting groups
|
|---|---|---|---|
|
Age, Categorical
<=18 years
|
127 Participants
n=39 Participants
|
36 Participants
n=41 Participants
|
163 Participants
n=35 Participants
|
|
Age, Categorical
Between 18 and 65 years
|
0 Participants
n=39 Participants
|
0 Participants
n=41 Participants
|
0 Participants
n=35 Participants
|
|
Age, Categorical
>=65 years
|
0 Participants
n=39 Participants
|
0 Participants
n=41 Participants
|
0 Participants
n=35 Participants
|
|
Age, Continuous
|
4.41 Years
STANDARD_DEVIATION 1.12 • n=39 Participants
|
4.65 Years
STANDARD_DEVIATION 1.25 • n=41 Participants
|
4.46 Years
STANDARD_DEVIATION 1.15 • n=35 Participants
|
|
Sex: Female, Male
Female
|
68 Participants
n=39 Participants
|
25 Participants
n=41 Participants
|
93 Participants
n=35 Participants
|
|
Sex: Female, Male
Male
|
59 Participants
n=39 Participants
|
11 Participants
n=41 Participants
|
70 Participants
n=35 Participants
|
|
Region of Enrollment
United States
|
127 participants
n=39 Participants
|
36 participants
n=41 Participants
|
163 participants
n=35 Participants
|
PRIMARY outcome
Timeframe: 48 Months from the date of randomizationPopulation: All subjects who had 48 month and baseline spleen function measurement.
The change in splenic function from the randomized control trial baseline measurement was one of the primary outcomes. The change in splenic function (worse vs not-worse) was compared between the randomized treatment groups (hydroxyurea vs placebo). The change in splenic function from baseline to 48 months was defined as worse if it changed from normal to decreased or absent, or decreased to absent; and not worse if it changed from decreased to decreased, normal to normal, decreased to normal, absent to absent, or absent to decreased.
Outcome measures
| Measure |
Randomized to Hydroxyurea
n=60 Participants
Subjects randomized to Hydroxyurea in the randomized phase III clinical trial.
|
Randomized to Placebo
n=49 Participants
Subjects randomized to Placebo in the randomized phase III clinical trial.
|
|---|---|---|
|
Change in Qualitative Spleen Function From Randomized Control Trial Baseline Measurement - Compared Between Children Randomized to Hydroxyurea vs Placebo
Splenic function - worse from baseline
|
16 Participants
|
15 Participants
|
|
Change in Qualitative Spleen Function From Randomized Control Trial Baseline Measurement - Compared Between Children Randomized to Hydroxyurea vs Placebo
Splenic function - not worse from baseline
|
44 Participants
|
34 Participants
|
PRIMARY outcome
Timeframe: 48 Months from the date of randomizationPopulation: All subjects who were known to be on hydroxyurea vs. off hydroxyurea at the 48 month visit, and had 48 month and baseline spleen function measurement.
The change in splenic function from the randomized control trial baseline measurement was one of the primary outcomes.The change in splenic function (worse vs not-worse) was compared between children who were known to be on hydroxyurea vs. off hydroxyurea at the time of the visit. The change in splenic function from baseline to 48 months was defined as worse if it changed from normal to decreased or absent, or decreased to absent; and not worse if it changed from decreased to decreased, normal to normal, decreased to normal, absent to absent, or absent to decreased.
Outcome measures
| Measure |
Randomized to Hydroxyurea
n=88 Participants
Subjects randomized to Hydroxyurea in the randomized phase III clinical trial.
|
Randomized to Placebo
n=18 Participants
Subjects randomized to Placebo in the randomized phase III clinical trial.
|
|---|---|---|
|
Change in Qualitative Spleen Function From Randomized Control Trial Baseline Measurement - Compared Between Children on Hydroxyurea vs Off Hydroxyurea at Study Visit
Splenic function - worse from baseline
|
26 Participants
|
5 Participants
|
|
Change in Qualitative Spleen Function From Randomized Control Trial Baseline Measurement - Compared Between Children on Hydroxyurea vs Off Hydroxyurea at Study Visit
Splenic function - not worse from baseline
|
62 Participants
|
13 Participants
|
PRIMARY outcome
Timeframe: 48 Months from the date of randomizationPopulation: All subjects who had 48 month and baseline pitted cell measurements.
The change in the percentage of pitted cell from randomized control trial baseline measurement was one of the primary outcomes. The change in the percentage of pitted cell was compared between the randomized treatment groups (hydroxyurea vs placebo).
Outcome measures
| Measure |
Randomized to Hydroxyurea
n=59 Participants
Subjects randomized to Hydroxyurea in the randomized phase III clinical trial.
|
Randomized to Placebo
n=49 Participants
Subjects randomized to Placebo in the randomized phase III clinical trial.
|
|---|---|---|
|
Change in the Percentage of Pitted Cell From Randomized Control Trial Baseline Measurement - Compared Between Children Randomized to Hydroxyurea vs Placebo
|
-1.70 Percentage of pitted cell
Interval -5.7 to 0.0
|
-1.00 Percentage of pitted cell
Interval -3.4 to -0.1
|
PRIMARY outcome
Timeframe: 72 Months from the date of randomizationPopulation: All subjects who had 72 month and baseline pitted cell measurements.
The change in the percentage of pitted cell from randomized control trial baseline measurement was one of the primary outcomes. The change in the percentage of pitted cell was compared between the randomized treatment groups (hydroxyurea vs placebo).
Outcome measures
| Measure |
Randomized to Hydroxyurea
n=70 Participants
Subjects randomized to Hydroxyurea in the randomized phase III clinical trial.
|
Randomized to Placebo
n=64 Participants
Subjects randomized to Placebo in the randomized phase III clinical trial.
|
|---|---|---|
|
Change in the Percentage of Pitted Cell From Randomized Control Trial Baseline Measurement - Compared Between Children Randomized to Hydroxyurea vs Placebo
|
-1.55 Percentage of pitted cell
Interval -5.7 to -0.3
|
-1.40 Percentage of pitted cell
Interval -4.75 to -0.35
|
PRIMARY outcome
Timeframe: 48 Months from the date of randomizationPopulation: All subjects who were known to be on hydroxyurea vs. off hydroxyurea at the 48 month visit, and had 48 month and baseline pitted cell measurements.
The change in the percentage of pitted cell from the randomized control trial baseline measurement was one of the primary outcomes. The change in the percentage of pitted cell was compared between children who were known to be on hydroxyurea vs. off hydroxyurea at the time of the visit.
Outcome measures
| Measure |
Randomized to Hydroxyurea
n=91 Participants
Subjects randomized to Hydroxyurea in the randomized phase III clinical trial.
|
Randomized to Placebo
n=15 Participants
Subjects randomized to Placebo in the randomized phase III clinical trial.
|
|---|---|---|
|
Change in the Percentage of Pitted Cell From Randomized Control Trial Baseline Measurement - Compared Between Children on Hydroxyurea vs Off Hydroxyurea at Study Visit
|
-1.40 Percentage of pitted cell
Interval -5.0 to -0.1
|
-0.60 Percentage of pitted cell
Interval -3.6 to 0.7
|
PRIMARY outcome
Timeframe: 72 Months from the date of randomizationPopulation: All subjects who were known to be on hydroxyurea vs. off hydroxyurea at the 72 month visit, and had 72 month and baseline pitted cell measurements.
The change in the percentage of pitted cell from the randomized control trial baseline measurement was one of the primary outcomes. The change in the percentage of pitted cell was compared between children who were known to be on hydroxyurea vs. off hydroxyurea at the time of the visit.
Outcome measures
| Measure |
Randomized to Hydroxyurea
n=104 Participants
Subjects randomized to Hydroxyurea in the randomized phase III clinical trial.
|
Randomized to Placebo
n=27 Participants
Subjects randomized to Placebo in the randomized phase III clinical trial.
|
|---|---|---|
|
Change in the Percentage of Pitted Cell From Randomized Control Trial Baseline Measurement - Compared Between Children on Hydroxyurea vs Off Hydroxyurea at Study Visit
|
-1.30 Percentage of pitted cell
Interval -4.65 to -0.25
|
-1.70 Percentage of pitted cell
Interval -11.1 to -0.5
|
PRIMARY outcome
Timeframe: 48 Months from the date of randomizationPopulation: All subjects who had 48 month and baseline Howell-Jolly Bodies measurements.
The change in Howell-Jolly Bodies from randomized control trial baseline measurement was one of the primary outcomes. The change in Howell-Jolly Bodies was compared between the randomized treatment groups (hydroxyurea vs placebo).
Outcome measures
| Measure |
Randomized to Hydroxyurea
n=52 Participants
Subjects randomized to Hydroxyurea in the randomized phase III clinical trial.
|
Randomized to Placebo
n=40 Participants
Subjects randomized to Placebo in the randomized phase III clinical trial.
|
|---|---|---|
|
Change in Howell-Jolly Bodies (HJB) From Randomized Control Trial Baseline Measurement - Compared Between Children Randomized to Hydroxyurea vs Placebo
|
1626.25 Number of HJB per 10⁶ red blood cell
Interval 921.0 to 2316.5
|
1553.00 Number of HJB per 10⁶ red blood cell
Interval 189.0 to 2231.5
|
PRIMARY outcome
Timeframe: 72 Months from the date of randomizationPopulation: All subjects who had 72 month and baseline Howell-Jolly Bodies measurements.
The change in Howell-Jolly Bodies from randomized control trial baseline measurement was one of the primary outcomes. The change in Howell-Jolly Bodies was compared between the randomized treatment groups (hydroxyurea vs placebo).
Outcome measures
| Measure |
Randomized to Hydroxyurea
n=22 Participants
Subjects randomized to Hydroxyurea in the randomized phase III clinical trial.
|
Randomized to Placebo
n=20 Participants
Subjects randomized to Placebo in the randomized phase III clinical trial.
|
|---|---|---|
|
Change in Howell-Jolly Bodies (HJB) From Randomized Control Trial Baseline Measurement - Compared Between Children Randomized to Hydroxyurea vs Placebo
|
1847.50 Number of HJB per 10⁶ red blood cell
Interval 1270.0 to 2474.0
|
1906.50 Number of HJB per 10⁶ red blood cell
Interval 721.5 to 2679.5
|
PRIMARY outcome
Timeframe: 48 Months from the date of randomizationPopulation: All subjects who were known to be on hydroxyurea vs. off hydroxyurea at the 48 month visit, and had 48 month and baseline Howell-Jolly Bodies measurements.
The change in Howell-Jolly Bodies from the randomized control trial baseline measurement was one of the primary outcomes. The change in Howell-Jolly Bodies was compared between children who were known to be on hydroxyurea vs. off hydroxyurea at the time of the visit.
Outcome measures
| Measure |
Randomized to Hydroxyurea
n=79 Participants
Subjects randomized to Hydroxyurea in the randomized phase III clinical trial.
|
Randomized to Placebo
n=11 Participants
Subjects randomized to Placebo in the randomized phase III clinical trial.
|
|---|---|---|
|
Change in Howell-Jolly Bodies (HJB) From Randomized Control Trial Baseline Measurement - Compared Between Children on Hydroxyurea vs Off Hydroxyurea at Study Visit
|
1661.00 Number of HJB per 10⁶ red blood cell
Interval 796.0 to 2325.0
|
1510.00 Number of HJB per 10⁶ red blood cell
Interval 594.0 to 1875.0
|
PRIMARY outcome
Timeframe: 72 Months from the date of randomizationPopulation: All subjects who were known to be on hydroxyurea vs. off hydroxyurea at the 72 month visit, and had 72 month and baseline Howell-Jolly Bodies measurements.
The change in Howell-Jolly Bodies (HJB) from the randomized control trial baseline measurement was one of the primary outcomes. The change in Howell-Jolly Bodies was compared between children who were known to be on hydroxyurea vs. off hydroxyurea at the time of the visit.
Outcome measures
| Measure |
Randomized to Hydroxyurea
n=29 Participants
Subjects randomized to Hydroxyurea in the randomized phase III clinical trial.
|
Randomized to Placebo
n=12 Participants
Subjects randomized to Placebo in the randomized phase III clinical trial.
|
|---|---|---|
|
Change in Howell-Jolly Bodies From Randomized Control Trial Baseline Measurement - Compared Between Children on Hydroxyurea vs Off Hydroxyurea at Study Visit
|
1972.00 Number of HJB per 10⁶ red blood cell
Interval 1270.0 to 2530.0
|
1500.50 Number of HJB per 10⁶ red blood cell
Interval 622.5 to 2043.5
|
Adverse Events
Randomized to Hydroxyurea
Randomized to Placebo
Serious adverse events
| Measure |
Randomized to Hydroxyurea
n=84 participants at risk
Subjects randomized to Hydroxyurea in the randomized phase III clinical trial.
|
Randomized to Placebo
n=79 participants at risk
Subjects randomized to Placebo in the randomized phase III clinical trial.
|
|---|---|---|
|
Respiratory, thoracic and mediastinal disorders
Acute chest syndrome
|
1.2%
1/84 • Number of events 1 • The date of consent to follow-up study I (FUS-I) through end of FUS-I, up to 2 years
Serious adverse event (SAE) were Death, Life-threatening event, Prolonged hospitalization (greater than 7 days), Splenic sequestration crisis, Stroke / transient ischemic attack (TIA), Acute chest syndrome, or ICU admissions, and occurred during the first 5 days following performance of an active assessment study.
|
1.3%
1/79 • Number of events 1 • The date of consent to follow-up study I (FUS-I) through end of FUS-I, up to 2 years
Serious adverse event (SAE) were Death, Life-threatening event, Prolonged hospitalization (greater than 7 days), Splenic sequestration crisis, Stroke / transient ischemic attack (TIA), Acute chest syndrome, or ICU admissions, and occurred during the first 5 days following performance of an active assessment study.
|
Other adverse events
Adverse event data not reported
Additional Information
Susan Assmann, PhD
New England Research Institutes, Inc.
Results disclosure agreements
- Principal investigator is a sponsor employee
- Publication restrictions are in place