Study to Evaluate the Effect of GBT440 on TCD in Pediatrics With Sickle Cell Disease (HOPE Kids 2)

March 6, 2026 updated by: Pfizer

A Phase 3, Randomized, Double-Blind, Placebo-Controlled Study of Voxelotor (GBT440) in Pediatric Participants With Sickle Cell Disease (HOPE Kids 2)

This study is a Phase 3, randomized, double-blind, placebo-controlled study of voxelotor in pediatric participants, aged ≥ 2 to < 15 years old, with Sickle Cell Disease. The primary objective is to evaluate the effect of voxelotor on the TCD (Transcranial Doppler Ultrasound) measurements in SCD participants in this age range.

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

This study is a Phase 3, randomized, double-blind, placebo-controlled study of voxelotor in pediatric participants, aged ≥ 2 to < 15 years old, with Sickle Cell Disease. The study will be conducted at approximately 50 international clinical sites, and will enroll approximately 224 participants. Participants will be randomized in a 1:1 ratio to receive voxelotor or placebo. All participants younger than 12 years of age and randomized to voxelotor will receive a dose based on their body weight, to provide exposure corresponding to the adult dose of 1500 mg/day.

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.
236

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 3

Expanded Access

Expanded Access

A way for patients with serious diseases or conditions who cannot participate in a clinical trial to gain access to a medical product that has not been approved by the U.S. Food and Drug Administration (FDA). Also called compassionate use. There are different expanded access types.
No longer available

No longer available

  • Available: Expanded access is currently available for this investigational treatment, and patients who are not participants in the clinical study may be able to gain access to the drug, biologic, or medical device being studied.
  • No longer available: Expanded access was available for this intervention previously but is not currently available and will not be available in the future.
  • Temporarily not available: Expanded access is not currently available for this intervention but is expected to be available in the future.
  • Approved for marketing: The intervention has been approved by the U.S. Food and Drug Administration for use by the public.
 outside the clinical trial. See expanded access record.

Contacts and Locations

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

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • Egypt
      • Alexandria, Egypt, 21131
        • Alexandria Clinical Research Center, Faculty of Medicine, Alexandria University
      • Cairo, Egypt, 11562
        • Abu El Rich Hospital, Cairo University Hospital
    • Abassia
      • Cairo, Abassia, Egypt, 11566
        • Ain Shams University Hospital- Clinical Research Center (MASRI)
    • Alsharkia
      • Zagazig, Alsharkia, Egypt
        • Zagazig University Hospital
  • Ghana
    • Ashanti Region
      • Kumasi, Ashanti Region, Ghana, 00233
        • Komfo Anokye Teaching Hospital
    • Greater Accra Region
      • Accra, Greater Accra Region, Ghana, GA-221-1570
        • Department of Child Health, University of Ghana Medical School, College of Health Sciences, Korle-Bu
  • Italy
      • Florence, Italy, 50139
        • Azienda Ospedaliera Universitaria Meyer "A.O.U. Meyer" - SOC "Oncologia, Ematologia e TCSE"
      • Napoli, Italy, 80138
        • Azienda Ospedaliera Universitaria (A.O.U.) "Luigi Vanvitelli"
      • Padua, Italy, 35128
        • Azienda Ospedaliera Universita' (AOU ) Padova
      • Padua, Italy, 35128
        • Azienda Ospedaliera Universita' (AOU) Padova
  • Kenya
      • Nairobi, Kenya, 00100
        • KEMRI CRDR Clinical Research Annex
      • Nairobi, Kenya, 00200
        • Strathmore University Medical Centre
      • Nairobi, Kenya, 100
        • Gertrude's Children Hospital
    • Siaya County
      • Kisumu, Siaya County, Kenya, 40600
        • Kemri/Crdr,Siaya,Kemri Clinical Research Annex
  • Nigeria
      • Enugu, Nigeria, 460000
        • University of Nigeria Teaching Hospital
      • Kaduna, Nigeria, 800212
        • Barau Dikko Teaching/Kaduna State University
      • Kano, Nigeria, 700233
        • Aminu Kano Teaching Hospital
    • Lagos
      • Surulere, Lagos, Nigeria, 100254
        • Lagos University Teaching Hospital
    • Oyo State
      • Ibadan, Oyo State, Nigeria, 200212
        • College of Medicine, University of Ibadan
  • Oman
      • Muscat, Oman
        • Sultan Qaboos University Hospital
  • Saudi Arabia
      • Riyadh, Saudi Arabia, 11481
        • King Abdullah International Medical Research Center (KAIMRC), Ministry of National Guard - Health
  • United Kingdom
      • London, United Kingdom, E1 1BB
        • Barts Health NHS Trust
  • United States
    • District of Columbia
      • Washington D.C., District of Columbia, United States, 20010
        • Children's National Medical Center
    • Florida
      • Miami, Florida, United States, 33136
        • University of Miami
    • Georgia
      • Atlanta, Georgia, United States, 30303
        • Children's Healthcare of Atlanta: Hughes Spalding
    • Massachusetts
      • Boston, Massachusetts, United States, 02115
        • Boston Children's Hospital
      • Boston, Massachusetts, United States, 02115
        • Boston Children's Hospital - Clinical Research Pharmacy
    • Mississippi
      • Jackson, Mississippi, United States, 39216
        • University of Mississippi Medical Center
    • Pennsylvania
      • Philadelphia, Pennsylvania, United States, 19104
        • The Children's Hospital of Philadelphia
    • South Carolina
      • Charleston, South Carolina, United States, 29425
        • Medical University of South Carolina
      • Charleston, South Carolina, United States, 29425
        • Medical University of South Carolina: Investigational Drug Services
      • Charleston, South Carolina, United States, 29425
        • Medical University of South Carolina: Shawn Jenkins Women's and Children's Hospital
    • Texas
      • Houston, Texas, United States, 77030
        • Texas Children's Hospital
      • Houston, Texas, United States, 77030
        • Texas Children's Hospital - Investigational Pharmacy
      • Houston, Texas, United States, 77030
        • Texas Children's Hospital- Wallace Tower

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

2 years to 14 years (Child)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Male or female participants with Sickle Cell Anemia (SCA) HbSS, HbSβ0 thalassemia genotype
  2. TCD time averaged maximum of the mean velocity (TAMMV) arterial cerebral blood flow ≥ 170 to < 200cm/sec during the Screening Period
  3. Hb ≥ 5.5 and ≤ 10.5 g/dL during screening
  4. For participants taking HU, the dose of HU (mg/kg) must be stable for at least 90 days prior to signing the informed consent form (ICF) and/or assent form, and with no anticipated need for dose adjustments (other than weight based) or for initiation of HU for non-chronic use during the study, in the opinion of the Investigator
  5. Written informed parental/guardian consent and participant assent (where applicable) has been obtained per IRB/EC policy and requirements, consistent with ICH guidelines.

Exclusion Criteria:

  1. Body weight < 10kg at the screening visit
  2. Hospitalization for VOC or acute chest syndrome (ACS) within the 14 days prior to execution of informed consent/assent
  3. More than 10 VOCs within the past 12 months that required hospitalization, emergency room, or clinic visit
  4. Stroke resulting in focal neurological deficit; previous silent infarcts are permitted.
  5. Known history or findings suggestive of significant cerebral vasculopathy
  6. History of seizure disorder
  7. Has been treated with erythropoietin or other hematopoietic growth factors within 28 days of signing informed consent/assent or if, in the opinion of the Investigator, there is an anticipated need for such agents during the study
  8. RBC transfusion therapy (also termed chronic, prophylactic, or preventative transfusion) or has received an RBC transfusion or exchange transfusion for any reason within 90 days of signing the informed consent/assent

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: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

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.
Placebo Comparator: Placebo
Matching placebo.
Drug: Placebo
Matching placebo.
Experimental: Voxelotor
Voxelotor 1500mg or equivalent daily as a tablet, dispersible tablet, or as powder for oral suspension.
Drug: Voxelotor
Participants are randomized 1:1 to receive voxelotor or placebo.

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
Measure Description
Time Frame
Change From Baseline in Time-Averaged Maximum of Mean Velocity (TAMMV) Arterial Cerebral Blood Flow at Week 24
Time Frame: Baseline (value at screening), Week 24
TAMMV is an ultrasound measurement used in transcranial Doppler (TCD) to assess blood flow in cerebral arteries. TCD flow velocities were categorized as follows: (i) Normal: < 170 centimeter per second (cm/sec); (ii) Conditional: 170 to < 200 cm/sec - the eligible participant population for this study; (iii) Abnormal: >= 200 cm/sec.
Baseline (value at screening), Week 24

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
Measure Description
Time Frame
Change From Baseline in TAMMV Arterial Cerebral Blood Flow at Week 48
Time Frame: Baseline (value at Screening), Weeks 48
TAMMV is an ultrasound measurement used in TCD to assess blood flow in cerebral arteries. TCD flow velocities were categorized as follows: (i) Normal: < 170 cm/sec; (ii) Conditional: 170 to < 200 cm/sec - the eligible participant population for this study; (iii) Abnormal: >= 200 cm/sec.
Baseline (value at Screening), Weeks 48
Time to Conversion to Abnormal TCD Flow
Time Frame: Up to 96 weeks
Time to conversion was the number of weeks from the date of randomization to the date of first determined TCD assessment when an abnormal TCD flow velocity (>= 200 cm/sec) was determined. TCD flow velocities were categorized as follows: (i) Normal: < 170 cm/sec; (ii) Conditional: 170 to < 200 cm/sec - the eligible participant population for this study; (iii) Abnormal: >= 200 cm/sec. The stratified Log Rank Test was stratified by stratification factors: baseline HU use (yes; no), age group (2 to <= 8 years; >8 to <15 years), and baseline TAMMV value (170 cm/sec to < 185 cm/sec; 185 cm/sec to < 200 cm/sec).
Up to 96 weeks
Time to Reversion to Normal TCD Flow
Time Frame: Up to 96 weeks
TCD was used to assess cerebral artery blood flow velocity in children with sickle cell disease (SCD). Time to first normal TCD flow was the number of weeks from randomization to the date of first determined normal TCD flow. Normal is < 170 cm/sec.
Up to 96 weeks
Percentage of Participants With TAMMV Reduced by >=15 cm/Sec From Baseline at Weeks 24, 48 and 96
Time Frame: At Weeks 24, 48 and 96
In this outcome measure, percentage of participants whose TAMMV reduced by >=15 cm/sec from Baseline at Weeks 24, 48 and 96 is reported. TAMMV is an ultrasound measurement used in TCD to assess blood flow in cerebral arteries. TCD flow velocities are categorized as follows: (i) Normal: < 170 cm/sec; (ii) Conditional: 170 to < 200 cm/sec - the eligible participant population for this study; (iii) Abnormal: >= 200 cm/sec.
At Weeks 24, 48 and 96
Change From Baseline in Hemoglobin (Hb) at Weeks 24, 48 and 96
Time Frame: Baseline (value at Screening), Weeks 24, 48 and 96
Change from baseline in hemoglobin at weeks 24, 48 and 96 were reported in this outcome measure.
Baseline (value at Screening), Weeks 24, 48 and 96
Percent Change From Baseline in Unconjugated Bilirubin at Weeks 24, 48 and 96
Time Frame: Baseline (value at Screening), Weeks 24, 48 and 96
Percent change from baseline in unconjugated bilirubin at weeks 24, 48 and 96 was reported in this outcome measure.
Baseline (value at Screening), Weeks 24, 48 and 96
Percent Change From Baseline in Reticulocyte at Weeks 24, 48 and 96
Time Frame: Baseline (value at Screening), Weeks 24, 48 and 96
Percent change from baseline in reticulocyte at weeks 24, 48 and 96 was reported in this outcome measure.
Baseline (value at Screening), Weeks 24, 48 and 96
Percent Change From Baseline in Absolute Reticulocyte at Weeks 24, 48 and 96
Time Frame: Baseline (value at Screening), Weeks 24, 48 and 96
Percent change from baseline in absolute reticulocyte at weeks 24, 48 and 96 was reported in this outcome measure.
Baseline (value at Screening), Weeks 24, 48 and 96
Percent Change From Baseline in Lactate Dehydrogenase (LDH) at Weeks 24, 48 and 96
Time Frame: Baseline (value at Screening), Weeks 24, 48 and 96
Percent change from baseline in LDH at weeks 24, 48 and 96 was reported in this outcome measure.
Baseline (value at Screening), Weeks 24, 48 and 96
Annualized Incidence Rate of Vaso-Occlusive Crises (VOCs)
Time Frame: From randomization to the last dose date, post-randomization HU initiation with no HU at baseline, end of study or study termination, whichever occurred earlier (maximum up to 110 weeks)
VOC was defined as a composite of acute painful crisis and/or acute chest syndrome (ACS). Annualized incidence rate was defined as total number of events per total person-years on treatment. Total person-years was the sum of participants treatment period in years, which included the time from randomization date to the earliest of (last dose date, post-randomization HU initiation for participants with no HU at baseline, end of study, or study termination). The 95% CI of rate displayed the exact Poisson confidence limits.
From randomization to the last dose date, post-randomization HU initiation with no HU at baseline, end of study or study termination, whichever occurred earlier (maximum up to 110 weeks)

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.
Pfizer

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.
  • Study Director: Pfizer CT.gov Call Center, Pfizer

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Helpful Links

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 (Actual)

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.
November 11, 2020

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.
January 18, 2024

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.
November 6, 2024

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).
December 20, 2019

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.
January 2, 2020

First Posted (Actual)

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.
January 6, 2020

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.
March 10, 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.
March 6, 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.
March 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.
  • GBT440-032
  • C5341021 (Other Identifier: Alias Study Number)
  • 2017-000903-26 (EudraCT Number)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical_trials/trial_data_and_results/data_requests.

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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