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

August 31, 2026 updated by: Robert I. Liem, Ann & Robert H Lurie Children's Hospital of Chicago

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

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.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Terminated

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

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.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
6

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 2
  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

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

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

10 years to 25 years (Child, Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • 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

Exclusion Criteria:

  • 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

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Hydroxyurea

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.
Drug: Hydroxyurea

Drug to be initiated at standard starting dose with dose escalation until maximum tolerated dose reached.

Other Names:
  • Experimental arm

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Time Frame
Mean Reduction in TRJV at M6
Time Frame: 6 months after initiation of hydroxyurea
6 months after initiation of hydroxyurea
Mean Reduction in TRJV at M12
Time Frame: 12 months after initiation of hydroxyurea
12 months after initiation of hydroxyurea

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Time Frame
Mean Increase Hb F% at M6
Time Frame: 6 months after initiation of hydroxyurea
6 months after initiation of hydroxyurea
Mean Increase in HbF% at M12
Time Frame: 12 months after initiation of hydroxyurea
12 months after initiation of hydroxyurea
Mean Reduction in LDH at M6
Time Frame: 6 months after initiation of hydroxyurea
6 months after initiation of hydroxyurea
Mean Reduction in LDH at M12
Time Frame: 12 months after initiation of hydroxyurea
12 months after initiation of hydroxyurea
Mean Reduction in Retic% at M6
Time Frame: 6 months after initiation of hydroxyurea
6 months after initiation of hydroxyurea
Mean Reduction in Retic% at M12
Time Frame: 12 months after initiation of hydroxyurea
12 months after initiation of hydroxyurea

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Ann & Robert H Lurie Children's Hospital of Chicago

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Robert I Liem, MD, Ann & Robert H Lurie Children's Hospital of Chicago

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
July 1, 2006

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
June 1, 2008

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
June 1, 2008

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
July 10, 2006

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 10, 2006

First Posted (Estimated)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
July 11, 2006

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
September 24, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 31, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
August 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 12735

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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