Sickle Cell DiseasePhase 1/2NCT00350844

Hydroxyurea for Children and Young Adults With Sickle Cell Disease and Pulmonary Hypertension

A Phase 1/2 study testing Hydroxyurea in people with Sickle Cell Disease and Pulmonary Hypertension, run by Ann & Robert H Lurie Children's Hospital of Chicago at 1 site in United States.

Terminated

Stopped early. The study ended before it was planned to and will not resume.

Official record

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Trial summary

The goal of this study is to test the hypothesis that hydroxyurea is effective for the specific treatment of secondary pulmonary hypertension found on screening in children and young adults with sickle cell disease. Read more about this study

Who is it for?: Ages 10 to 25 years
Conditions the study is for: Sickle Cell Disease, Pulmonary Hypertension
What is being tested?: Hydroxyurea
Could I receive a placebo?: No, everyone receives an active treatment
How many people: 6 participants
Where: 1 siteUnited States
Study dates: Jul 2006to Jun 2008
Phase: Phase 1/2
Are there results?: Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

Ages 10 to 25 years
All sexes
No healthy volunteers
Child, Adult

Who may be able to join

Age between 10 and 25 years old
Sickle cell disease with hemoglobin SS, SC or S-B^0 thalassemia confirmed on hemoglobin electrophoresis
Tricuspid regurgitant jet velocity (TRJV) equal to or greater than 2.5 m/sec on 2 baseline Doppler echocardiograms at least 3 months apart

Who cannot join

Patients already being treated with hydroxyurea
Patients on a chronic transfusion protocol
Patients with evidence of hepatic (alanine aminotransferase [ALT] equal to or greater than 2 SD above normal) or renal dysfunction (creatinine [Cr] equal to or greater than 2 SD above normal)
Patients who are pregnant
Patients with documented causes of severe pulmonary hypertension other than from SCD

Trial locations and contacts

1 site in 1 country.

United States1 site

Ann & Robert H Lurie Children's Hospital of Chicago
Chicago, Illinois, 60611

Other trials in United States

About this study

Official title: A Pilot Study of Hydroxyurea for the Treatment of Pulmonary Hypertension in Children and Young Adults With Sickle Cell Disease

Read the detailed description

Increasing evidence suggests that pulmonary hypertension, defined by an elevated tricuspid regurgitant jet velocity (TRJV) on echocardiogram, is a major cause of morbidity and mortality in adults with sickle cell disease (SCD). However, both the prevalence and optimal treatment of pulmonary hypertension in children and young adults with SCD are unknown.

We hypothesize that short term therapy with hydroxyurea will decrease TRJV in children and young adults with pulmonary hypertension found on screening. Patients eligible for treatment will have had evidence of pulmonary hypertension on at least 2 screening echocardiograms. Baseline laboratory tests will be obtained and other causes of secondary pulmonary hypertension will be excluded prior to initiation of treatment. Patients will be treated with hydroxyurea according to a standard dose escalation schedule for a total of 12 months. A clinic visit will be required every 2 months and standard screening for toxicity will be performed monthly. There will be an interim analysis of the primary outcome at 6 months following therapy.

Conditions: Sickle Cell Disease, Pulmonary Hypertension
Being tested: Hydroxyurea
Keywords: Sickle Cell Disease, Pulmonary Hypertension
Medical subject headings: Anemia, Sickle Cell, Hypertension, Pulmonary

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

HydroxyureaDrug
Also called Experimental arm
Drug to be initiated at standard starting dose with dose escalation until maximum tolerated dose reached.

Study groups in NCT00350844
Study group	Role	What they receive
Hydroxyurea	Experimental	Single arm pilot of hydroxyurea in the experimental arm with starting dose of 20 mg/kg/day po and dose escalation every 2 months until maximum tolerated dose. Receives: Drug: Hydroxyurea

What is being measured

The primary outcome is the main question the study is designed to answer.

Mean Reduction in TRJV at M6
Measured: 6 months after initiation of hydroxyurea
Mean Reduction in TRJV at M12
Measured: 12 months after initiation of hydroxyurea

Secondary outcomes (6)

Mean Increase Hb F% at M6
Measured: 6 months after initiation of hydroxyurea
Mean Increase in HbF% at M12
Measured: 12 months after initiation of hydroxyurea
Mean Reduction in LDH at M6
Measured: 6 months after initiation of hydroxyurea
Mean Reduction in LDH at M12
Measured: 12 months after initiation of hydroxyurea
Mean Reduction in Retic% at M6
Measured: 6 months after initiation of hydroxyurea
Mean Reduction in Retic% at M12
Measured: 12 months after initiation of hydroxyurea

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

Jul 2006Jun 2008

First posted11 Jul 2006 (estimated)
Study startJul 2006
Primary completionJun 2008
Study completionJun 2008

Why it stopped: Low subject accrual

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
Other trials for Sickle Cell DiseaseStudies of the same condition, open and under way.
What the trial phases meanHow a treatment moves from first tests in people to approval.

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design

Study type: Interventional
Phase: Phase 1/2
Primary purpose: Treatment
Allocation: Not applicable
Intervention model: Single group
Masking: None (open label)
Enrolment: 6 participants (actual)

IDs, dates and publications

ClinicalTrials.gov ID: NCT00350844
Sponsor's protocol ID: 12735
Status last verified: Aug 2026
First submitted: 10 Jul 2006
Last updated: 24 Sep 2026
Results posted: Yes, on ClinicalTrials.gov
Data monitoring committee: No
FDA-regulated drug: Yes
FDA-regulated device: No

Want to know more?

The sponsor has not listed a contact. The official record may have more details.

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

See locations

Active, not recruitingPhase 1/2
Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of Long-term Mitapivat Dosing in Subjects With Stable Sickle Cell Disease: An Extension of a Phase I Pilot Study of Mitapivat
Sickle Cell Disease, Hemolytic Anemia
RecruitingObservational study
HPC Offered for PRESERVE Expansion
Bone Marrow Transplant (BMT)
RecruitingPhase 1
Study to Evaluate the Safety and Tolerability of Escalating Doses of Fostamatinib in Subjects With Stable Sickle Cell Disease
Sickle Cell Disorders, Sickle Cell Disease
RecruitingPhase 4
Clinical and Biomarker Effects of Depot Medroxyprogesterone Acetate in Females With Sickle Cell Disease
Sickle Cell Disease (SCD), Vaso-Occlusive Pain Episode in Sickle Cell Disease
Not yet recruitingPhase 1
Buprenorphine for the Management of Pain in Children With Sickle Cell Disease
Sickle Cell Disease (SCD), Sickle Cell Disease Vaso-occlusive Crisis

All Sickle Cell Disease trials

Study at a glance

From the registry record, last updated by the sponsor on 24 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: A Pilot Study of Hydroxyurea for the Treatment of Pulmonary Hypertension in Children and Young Adults With Sickle Cell Disease
ClinicalTrials.gov ID: NCT00350844
Acronym / sponsor ID: 12735
Conditions: Sickle Cell Disease, Pulmonary Hypertension
Keywords: Sickle Cell Disease, Pulmonary Hypertension
Phase: Phase 1/2
Study type: Interventional
Recruitment status: TerminatedReason stopped: Low subject accrual
Enrolment: 6 participants (actual)
Lead sponsor: Ann & Robert H Lurie Children's Hospital of ChicagoUniversity, hospital or other
Study start: Jul 2006
Primary completion: Jun 2008 (actual)
Study completion: Jun 2008 (actual)
First posted: 11 Jul 2006 (estimated)
Results: Posted 8 May 2013

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

Detailed description

Study design

Primary purpose: Treatment
Allocation: Not applicable
Intervention model: Single group
Masking: None (open label)
Number of arms: 1

Arm	Type	Receives
Hydroxyurea	Experimental	Drug: HydroxyureaSingle arm pilot of hydroxyurea in the experimental arm with starting dose of 20 mg/kg/day po and dose escalation every 2 months until maximum tolerated dose.

Who may qualify

Ages: 10 to 25 years
Sex: All
Healthy volunteers: Not accepted
Age groups: Child, Adult

Key inclusion criteria (3 listed)

Age between 10 and 25 years old
Sickle cell disease with hemoglobin SS, SC or S-B^0 thalassemia confirmed on hemoglobin electrophoresis
Tricuspid regurgitant jet velocity (TRJV) equal to or greater than 2.5 m/sec on 2 baseline Doppler echocardiograms at least 3 months apart

Key exclusion criteria (5 listed)

Patients already being treated with hydroxyurea
Patients on a chronic transfusion protocol
Patients with evidence of hepatic (alanine aminotransferase [ALT] equal to or greater than 2 SD above normal) or renal dysfunction (creatinine [Cr] equal to or greater than 2 SD above normal)
Patients who are pregnant
Patients with documented causes of severe pulmonary hypertension other than from SCD

Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.

Interventions

Intervention	Type	Arms
HydroxyureaAlso: Experimental armDrug to be initiated at standard starting dose with dose escalation until maximum tolerated dose reached.	Drug	Hydroxyurea

Primary outcome

Mean Reduction in TRJV at M6
Time frame: 6 months after initiation of hydroxyurea
Mean Reduction in TRJV at M12
Time frame: 12 months after initiation of hydroxyurea

6 secondary outcomes

Mean Increase Hb F% at M6
Time frame: 6 months after initiation of hydroxyurea
Mean Increase in HbF% at M12
Time frame: 12 months after initiation of hydroxyurea
Mean Reduction in LDH at M6
Time frame: 6 months after initiation of hydroxyurea
Mean Reduction in LDH at M12
Time frame: 12 months after initiation of hydroxyurea
Mean Reduction in Retic% at M6
Time frame: 6 months after initiation of hydroxyurea
Mean Reduction in Retic% at M12
Time frame: 12 months after initiation of hydroxyurea

Results and safety

Results posted to the registry on 8 May 2013, as reported by the sponsor. Figures are copied from the record, not re-analysed. Full results on ClinicalTrials.gov.

Participant flow

Group	Started	Completed
Hydroxyurea	6	4

Primary outcome: Mean Reduction in TRJV at M6

Time frame: 6 months after initiation of hydroxyurea. Mean (Standard Deviation). Unit: m/sec

Measure	Hydroxyurea n = 4
Value	0.3 (0.5)

Population analysed: Only 4/6 participants had evaluable data at M6

Primary outcome: Mean Reduction in TRJV at M12

Time frame: 12 months after initiation of hydroxyurea. Mean (Standard Deviation). Unit: m/sec

Measure	Hydroxyurea n = 4
Value	0.6 (0.2)

Population analysed: Only 4/6 participants had evaluable data at M12

6 secondary outcomes are reported in the full results.

Adverse events

Other adverse events reported at 0% frequency or more

Group	Serious adverse events	Other adverse events	Deaths
Hydroxyurea	0 of 6 (0%)	0 of 6 (0%)	Not reported

Limitations and caveats (from the sponsor): Given our small sample size, no other secondary data were evaluated and no further statistical analysis was performed on reported primary or secondary data.

Loading the posted results from ClinicalTrials.gov…

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 24 Sep 2026.
Posted resultsParticipant flow, baseline, all outcome measures and adverse events.

Related trials for Sickle Cell Disease

Active, not recruitingPhase 1/2
Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of Long-term Mitapivat Dosing in Subjects With Stable Sickle Cell Disease: An Extension of a Phase I Pilot Study of Mitapivat
Sickle Cell Disease, Hemolytic Anemia
RecruitingObservational study
HPC Offered for PRESERVE Expansion
Bone Marrow Transplant (BMT)
RecruitingPhase 1
Study to Evaluate the Safety and Tolerability of Escalating Doses of Fostamatinib in Subjects With Stable Sickle Cell Disease
Sickle Cell Disorders, Sickle Cell Disease
RecruitingPhase 4
Clinical and Biomarker Effects of Depot Medroxyprogesterone Acetate in Females With Sickle Cell Disease
Sickle Cell Disease (SCD), Vaso-Occlusive Pain Episode in Sickle Cell Disease
Not yet recruitingPhase 1
Buprenorphine for the Management of Pain in Children With Sickle Cell Disease
Sickle Cell Disease (SCD), Sickle Cell Disease Vaso-occlusive Crisis

Referral and contact

AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.

Robert I Liem, MD principal investigator

Ann & Robert H Lurie Children's Hospital of Chicago

1 site in 1 country: see every site and its status.

Questions about this trial

What is this clinical trial studying?

A Phase 1/2 study testing Hydroxyurea in people with Sickle Cell Disease and Pulmonary Hypertension, run by Ann & Robert H Lurie Children's Hospital of Chicago at 1 site in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 3 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: stopped early, as of the sponsor's last update on 24 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this combined phase mean?

Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.

Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

Yes. Results are posted in the registry (first posted 8 May 2013). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Mean Reduction in TRJV at M6 (time frame: 6 months after initiation of hydroxyurea). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT00350844.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 24 Sep 2026.