Sickle Cell DiseaseEarly Phase 1NCT05662098

Alternative Dosing And Prevention of Transfusions (ADAPT)

A Early Phase 1 study testing Hydroxyurea in people with Sickle Cell Disease, run by Children's Hospital Medical Center, Cincinnati at 1 site in Uganda.

Active, not recruiting

Under way, not looking for participants. Everyone needed has enrolled. The study is still running.

Official record

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Trial summary

ADAPT is a prospective cohort study at Jinja Regional Referral Hospital (JRRH) primarily to assess the effect of hydroxyurea on blood transfusion utilization and secondarily to determine the feasibility of PK-guided hydroxyurea dosing. Read more about this study

Who is it for?: Ages 12 months to 10 years
Conditions the study is for: Sickle Cell Disease
What is being tested?: Hydroxyurea
Type of treatment: Pill or oral medicine
Could I receive a placebo?: No, everyone receives an active treatment
How many people: 100 participants
Where: 1 siteUganda
Study dates: 16 Jun 2022to 31 Dec 2027
Phase: Early Phase 1
Are there results?: Not yet: the study is under way

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 12 months to 10 years
All sexes
No healthy volunteers
Child

Who may be able to join

Patients with documented HbSS disease
Age: ≥ 12 months and ≤ 10 years of age, at the time of enrollment
Parent or guardian willing and able to provide informed consent
Able to comply with all study related treatments, evaluations, and follow-up

Who cannot join

Current hydroxyurea treatment (or within the past 6 months)
Regular blood transfusions (6 or more within the past 12 months)
Transfusion within the last 30 days (temporary exclusion)
Known malignancy or other known chronic illnesses including but not limited to active tuberculosis, renal disease
Current participation in other therapeutic clinical trials, or within 6 months of prior disease-modifying treatments

Trial locations and contacts

1 site in 1 country.

Uganda1 site

Jinja Regional Referral Hospital (JRRH), Department of Paediatrics, Sickle Cell Clinic
Jinja

Other trials in Uganda

About this study

Official title: Alternative Dosing And Prevention of Transfusions (ADAPT): A Prospective Study to Reduce Transfusion Requirements for Children With Sickle Cell Anemia Using Pharmacokinetics-based Hydroxyurea Dosing

Read the detailed description

Hypothesis

There will be a 50% reduction in the rate of blood transfusions received during the hydroxyurea treatment period compared with the pre-treatment period.
A PK-guided starting dose will be generated for 80% of participants.
Participants on PK-guided hydroxyurea treatment will require 25% fewer blood transfusions during their first year of hydroxyurea than those on dose escalation.

Conditions: Sickle Cell Disease
Being tested: Hydroxyurea
Keywords: Pharmacokinetics, Hydroxyurea, Transfusion
Medical subject headings: Anemia, Sickle Cell

What participants receive

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

HydroxyureaDrug
All participants will receive an individualized PK hydroxyurea assessment. Participants for whom the PK-process successfully generates a dose in the predicted treatment range of 15-35 mg/kg/day, will start on that personalized dose. Participants for whom the process does not generate a starting hydroxyurea dose in the predicted treatment range, due to potential pitfalls in lab draws, serum storage, sample processing, or hydroxyurea analysis, will start at a default dose of 20.0 ± 2.5 mg/kg/day. For all participants, the hydroxyurea dose will be adjusted as needed based on blood counts to establish the optimal dose. Where necessary, a weekly dosing average will be determined, so that treatment can occur solely with locally available and affordable 500mg hydroxyurea capsules.

Study groups in NCT05662098
Study group	Role	What they receive
Treatment	Experimental	All participants will receive an individualized PK hydroxyurea assessment. Participants for whom the PK-process successfully generates a dose in the predicted treatment range of 15-35 mg/kg/day, will start on that personalized dose. Participants for whom the process does not generate a starting hydroxyurea dose in the predicted treatment range, due to potential pitfalls in lab draws, serum storage, sample processing, or hydroxyurea analysis, will start at a default dose of 20.0 ± 2.5 mg/kg/day. For all participants, the hydroxyurea dose will be adjusted as needed based on blood counts to establish the optimal dose. Where necessary, a weekly dosing average will be determined, so that treatment can occur solely with locally available and affordable 500mg hydroxyurea capsules. Receives: Drug: Hydroxyurea

What is being measured

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

To compare the rates of blood transfusions overall and by specific indications in children with sickle cell anaemia (SCA), prior to and during hydroxyurea treatment
The incidence rate ratio of transfusions overall and by specific indication during the screening phase as compared to the treatment phase
Measured: One year (Enrollment - Month 15)

Secondary outcomes (1)

To determine clinical and laboratory factors associated with reduction in blood transfusions for children with SCA on hydroxyurea treatment
The relative risk of transfusion due to the most common clinical diagnoses and laboratory factors for children with SCA on hydroxyurea treatment.
Measured: One year (Enrollment - Month 15)

Timeline

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

16 Jun 202231 Dec 2027

First posted22 Dec 2022
Study start16 Jun 2022
Primary completion31 Dec 2026 (estimated)
Study completion31 Dec 2027 (estimated)

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Publications (2)Papers the sponsor has linked to this study.
Other trials for Sickle Cell DiseaseStudies of the same condition, open and under way.
More trials run by Children's Hospital Medical Center, CincinnatiThe sponsor's other registered studies.
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: Early Phase 1
Primary purpose: Treatment
Allocation: Not applicable
Intervention model: Single group
Model description: ADAPT is a prospective cohort study at Jinja Regional Referral Hospital (JRRH) primarily to assess the effect of hydroxyurea on blood transfusion utilization and secondarily to determine the feasibility of PK-guided hydroxyurea dosing.
Masking: None (open label)
Enrolment: 100 participants (estimated)

IDs, dates and publications

ClinicalTrials.gov ID: NCT05662098
Sponsor's protocol ID: ADAPT
Status last verified: Apr 2026
First submitted: 4 Oct 2022
Last updated: 9 Apr 2026
Results posted: No
Data monitoring committee: No
FDA-regulated drug: No
FDA-regulated device: No

Publications

Power-Hays A, Namazzi R, Dong M, Kazinga C, Kato C, Aliwuya S, McElhinney K, Conroy AL, Lane A, John C, Vinks AA, Latham T, Opoka RO, Ware RE. The feasibility of pharmacokinetic-based dosing of hydroxyurea for children with sickle cell anaemia in Uganda: Baseline results of the alternative dosing and prevention of transfusions trial. Br J Clin Pharmacol. 2025 Jun;91(6):1865-1872. doi: 10.1111/bcp.70071.
PubMed 40441700
Power-Hays A, Namazzi R, Dong M, Kazinga C, Kato C, Aliwuya S, McElhinney K, Conroy AL, Lane A, John C, Vinks AA, Latham T, Opoka RO, Ware RE. The feasibility of pharmacokinetic-based dosing of hydroxyurea for children with sickle cell anaemia in Uganda: Baseline results of the alternative dosing and prevention of transfusions trial. Br J Clin Pharmacol. 2025 Apr 13;91(6):1865-72. doi: 10.1002/bcp.70071. Online ahead of print.
PubMed 40222814

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
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HPC Offered for PRESERVE Expansion
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Study to Evaluate the Safety and Tolerability of Escalating Doses of Fostamatinib in Subjects With Stable Sickle Cell Disease
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RecruitingPhase 4
Clinical and Biomarker Effects of Depot Medroxyprogesterone Acetate in Females With Sickle Cell Disease
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All Sickle Cell Disease trials

Study at a glance

From the registry record, last updated by the sponsor on 9 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: Alternative Dosing And Prevention of Transfusions (ADAPT): A Prospective Study to Reduce Transfusion Requirements for Children With Sickle Cell Anemia Using Pharmacokinetics-based Hydroxyurea Dosing
ClinicalTrials.gov ID: NCT05662098
Acronym / sponsor ID: ADAPT
Conditions: Sickle Cell Disease
Keywords: Pharmacokinetics, Hydroxyurea, Transfusion
Phase: Early Phase 1
Study type: Interventional
Recruitment status: Active, not recruiting
Enrolment: 100 participants (estimated)
Lead sponsor: Children's Hospital Medical Center, CincinnatiUniversity, hospital or other
Collaborators: Jinja Regional Referral Hospital (JRRH), Sickle Cell Clinic, Jinja, Uganda
Study start: 16 Jun 2022 (actual)
Primary completion: 31 Dec 2026 (estimated)
Study completion: 31 Dec 2027 (estimated)
First posted: 22 Dec 2022 (actual)
Results: Not posted in the source record

Clinical summary

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

Detailed description

Hypothesis

There will be a 50% reduction in the rate of blood transfusions received during the hydroxyurea treatment period compared with the pre-treatment period.
A PK-guided starting dose will be generated for 80% of participants.
Participants on PK-guided hydroxyurea treatment will require 25% fewer blood transfusions during their first year of hydroxyurea than those on dose escalation.

Study design

Primary purpose: Treatment
Allocation: Not applicable
Intervention model: Single group
Masking: None (open label)
Number of arms: 1
Model description: ADAPT is a prospective cohort study at Jinja Regional Referral Hospital (JRRH) primarily to assess the effect of hydroxyurea on blood transfusion utilization and secondarily to determine the feasibility of PK-guided hydroxyurea dosing.

Arm	Type	Receives
Treatment	Experimental	Drug: HydroxyureaAll participants will receive an individualized PK hydroxyurea assessment. Participants for whom the PK-process successfully generates a dose in the predicted treatment range of 15-35 mg/kg/day, will start on that personalized dose. Participants for whom the process does not generate a starting hydroxyurea dose in the predicted treatment range, due to potential pitfalls in lab draws, serum storage, sample processing, or hydroxyurea analysis, will start at a default dose of 20.0 ± 2.5 mg/kg/day. For all participants, the hydroxyurea dose will be adjusted as needed based on blood counts to establish the optimal dose. Where necessary, a weekly dosing average will be determined, so that treatment can occur solely with locally available and affordable 500mg hydroxyurea capsules.

Who may qualify

Ages: 12 months to 10 years
Sex: All
Healthy volunteers: Not accepted
Age groups: Child

Key inclusion criteria (4 listed)

Patients with documented HbSS disease
Age: ≥ 12 months and ≤ 10 years of age, at the time of enrollment
Parent or guardian willing and able to provide informed consent
Able to comply with all study related treatments, evaluations, and follow-up

Key exclusion criteria (5 listed)

Current hydroxyurea treatment (or within the past 6 months)
Regular blood transfusions (6 or more within the past 12 months)
Transfusion within the last 30 days (temporary exclusion)
Known malignancy or other known chronic illnesses including but not limited to active tuberculosis, renal disease
Current participation in other therapeutic clinical trials, or within 6 months of prior disease-modifying treatments

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
HydroxyureaAll participants will receive an individualized PK hydroxyurea assessment. Participants for whom the PK-process successfully generates a dose in the predicted treatment range of 15-35 mg/kg/day, will start on that personalized dose. Participants for whom the process does not generate a starting hydroxyurea dose in the predicted treatment range, due to potential pitfalls in lab draws, serum storage, sample processing, or hydroxyurea analysis, will start at a default dose of 20.0 ± 2.5 mg/kg/day. For all participants, the hydroxyurea dose will be adjusted as needed based on blood counts to establish the optimal dose. Where necessary, a weekly dosing average will be determined, so that treatment can occur solely with locally available and affordable 500mg hydroxyurea capsules.	Drug	Treatment

Primary outcome

To compare the rates of blood transfusions overall and by specific indications in children with sickle cell anaemia (SCA), prior to and during hydroxyurea treatment
Time frame: One year (Enrollment - Month 15)
The incidence rate ratio of transfusions overall and by specific indication during the screening phase as compared to the treatment phase

1 secondary outcome

To determine clinical and laboratory factors associated with reduction in blood transfusions for children with SCA on hydroxyurea treatment
Time frame: One year (Enrollment - Month 15)

Results and safety

This study is still under way. Results are not available in the source record yet.

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 9 Apr 2026.
Derived from this study: PubMed 40441700Power-Hays A, Namazzi R, Dong M, Kazinga C, Kato C, Aliwuya S, McElhinney K, Conroy AL, Lane A, John C, Vinks AA, Latham T, Opoka RO, Ware RE. The feasibility of pharmacokinetic-based dosing of hydroxyurea for children with sickle cell anaemia in Uganda: Baseline results of the alternative dosing and prevention of transfusions trial. Br J Clin Pharmacol. 2025 Jun;91(6):1865-1872. doi: 10.1111/bcp.70071.
Derived from this study: PubMed 40222814Power-Hays A, Namazzi R, Dong M, Kazinga C, Kato C, Aliwuya S, McElhinney K, Conroy AL, Lane A, John C, Vinks AA, Latham T, Opoka RO, Ware RE. The feasibility of pharmacokinetic-based dosing of hydroxyurea for children with sickle cell anaemia in Uganda: Baseline results of the alternative dosing and prevention of transfusions trial. Br J Clin Pharmacol. 2025 Apr 13;91(6):1865-72. doi: 10.1002/bcp.70071. Online ahead of print.

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
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Not yet recruitingPhase 1
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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.

Russell Ware, MD, PhD study director

Children's Hospital Medical Center, Cincinnati

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

Questions about this trial

What is this clinical trial studying?

A Early Phase 1 study testing Hydroxyurea in people with Sickle Cell Disease, run by Children's Hospital Medical Center, Cincinnati at 1 site in Uganda.

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 4 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: under way, not looking for participants, as of the sponsor's last update on 9 Apr 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 Uganda. 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 phase mean?

Early Phase 1 (sometimes called Phase 0) studies give a very small amount of a treatment to a few people, mainly to see how the body handles it.

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

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

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?

To compare the rates of blood transfusions overall and by specific indications in children with sickle cell anaemia (SCA), prior to and during hydroxyurea treatment (time frame: One year (Enrollment - Month 15)). 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 NCT05662098, which also lists 2 linked publications.

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 9 Apr 2026.