Sickle Cell DiseasePhase 2HOPE-KIDSNCT02850406
Study to Evaluate the Effect of GBT440 in Pediatrics With Sickle Cell Disease
A Phase 2 study testing Voxelotor in people with Sickle Cell Disease, run by Pfizer at 20 sites in 3 countries.
Trial summary
This study consists of four parts, Parts A, B, C, and D. Part A is a single dose pharmacokinetic (PK) study in pediatric participants with Sickle Cell Disease ages 6 to 17 years. Read more about this study
- Who is it for?
- Ages 6 months to 17 years
- Conditions the study is for
- Sickle Cell Disease
- What is being tested?
- Voxelotor
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 147 participants
- Where
- 20 sitesin 3 countries
- Study dates
- 5 Jul 2016to 2 Oct 2023
- Phase
- Phase 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 6 months to 17 years
- All sexes
- No healthy volunteers
- Child
Who may be able to join
- Male or female participants with homozygous hemoglobin SS (HbSS) or hemoglobin S beta0 thalassemia (HbS β0thal)
- Age:
- Part A - 6 to 17 years of age
- Part B - 12 to 17 years of age
- Part C - 4 to 17 years of age
- Part D - 6 months to <4 years of age
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- Hydroxyurea (HU) therapy:
- Parts A, B, and C: A participant taking hydroxyurea (HU) may be enrolled if the dose has been stable for at least 3 months with no anticipated need for dose adjustment during the study and no sign of hematological toxicity.
- Part D: A participant taking HU may be enrolled if the dose has been stable for at least 1 month. Titration to the maximum tolerated dose (MTD) is allowed during the study.
- Hemoglobin (HB):
- Part A - No restriction
- Parts B, C, \& D - Hb ≤ 10.5 g/dL
- For Part C only: Participants 12 to 17 years of age must have a TCD velocity of ≥ 140 cm/sec measured anytime during screening.
Who cannot join
- Any one of the following requiring medical attention within 14 days of signing the Informed Consent Form (ICF):
- Vaso-occlusive crisis (VOC)
- Acute chest syndrome (ACS)
- Splenic sequestration crisis
- Dactylitis
- Requires chronic transfusion therapy
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- History of stroke or meeting criteria for primary stroke prophylaxis (history of two TCD measurements ≥ 200 cm/sec by non-imaging TCD or ≥185 cm/sec by TCDi).
- Transfusion within 30 days prior to signing the ICF
- Body weight <5 kg for 1 month prior to the screening visit and at the screening visit.
Trial locations and contacts
20 sites in 3 countries.
20 sites in 3 countries
United States13 sites
Children's Healthcare of Atlanta Scottish Rite
Atlanta, Georgia, 30342
Our Lady of the Lake Children's Hospital (IP Address)
Baton Rouge, Louisiana, 70809
Brentwood Clinic UCSF Benioff Children's Hospital Oakland
Brentwood, California, 94513
Ann & Robert H. Lurie Children's Hospital of Chicago
Chicago, Illinois, 60611
University of Illinois at Chicago Clinical Research Center
Chicago, Illinois, 60612
University Hospitals Cleveland Medical Center, Rainbow Babies & Children's Hospital
Cleveland, Ohio, 44106
Brody School of Medicine at East Carolina University
Greenville, North Carolina, 27834
Children's Mercy Hospital
Kansas City, Missouri, 64108
St. Jude Children's Research Hospital
Memphis, Tennessee, 38105
Rutgers-Robert Wood Johnson Medical School
New Brunswick, New Jersey, 08903
The Children's Hospital of Philadelphia
Philadelphia, Pennsylvania, 19104
Children's Hospital of Pittsburgh of UPMC
Pittsburgh, Pennsylvania, 15224
Children's National Medical Center
Washington D.C., District of Columbia, 20010
United Kingdom4 sites
University College London Hospital, NHS Foundation Trust
London, Greater London, NW1 2PG
Barts Health NHS Trust, The Royal London Hospital
London, E1 1BB
Guy's and St Thoma's NHS Foundation Trust, Evelina London Children's Hospital
London, SE1 7EH
Manchester University NHS Foundation Trust, Royal Manchester Children's Hospital
Manchester, M13 9WL
Lebanon3 sites
American University of Beirut - Medical Center
Beirut
Rafik Hariri University Hospital
Beirut
Nini Hospital
Tripoli
About this study
Official title: A Phase 2a, Open-label, Single and Multiple Dose Study to Evaluate the Pharmacokinetics, Safety, Tolerability and Treatment Effect of GBT440 in Pediatric Participants With Sickle Cell Disease
This study consists of four parts, Parts A, B, C, and D.
- Part A is a single dose pharmacokinetic (PK) study in pediatric participants with Sickle Cell Disease ages 6 to 17 years.
- Part B is a multiple dose, safety, exploratory, efficacy, and PK study in adolescent participants with Sickle Cell Disease ages 12 to 17 years.
- Part C is a multiple dose, safety, tolerability, and PK study, which includes the assessment of hematological effects and the effect on TCD flow velocity of voxelotor in pediatric participants with Sickle Cell Disease ages 4 to 17 years.
- Part D is a multiple dose, safety, tolerability, and PK study, which examines the hematological effects of voxelotor in pediatric participants with Sickle Cell Disease ages 6 months to < 4 years.
- Conditions
- Sickle Cell Disease
- Being tested
- Voxelotor
- 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.
VoxelotorDrug
- Part A: Voxelotor will be administered as oral capsules or tablets
- Part B: Voxelotor will be administered as oral capsules or tablets
- Part C: Voxelotor will be administered as oral dispersible tablets or powder for oral suspension
- Part D: Voxelotor will be administered as oral dispersible tablets or powder for oral suspension
| Study group | Role | What they receive |
|---|---|---|
| Voxelotor | Experimental | Subjects to receive daily oral dosing of voxelotor according to which Part (A, B, C, or D), the subject is participating in:
* Part A: Subjects to receive daily oral dosing of voxelotor for 1 day (single dose)
* Part B: Subjects to receive daily oral dosing of voxelotor for up to 24 weeks (multiple dose)
* Part C: Subjects to receive daily oral dosing of voxelotor for up to 48 weeks (1500mg or 1500mg equivalent dose)
* Part D: Subjects to receive daily oral dosing of voxelotor for up to 48 weeks (1500mg equivalent dose) Receives: Drug: Voxelotor |
What is being measured
The primary outcome is the main question the study is designed to answer.
Part A: Maximum Concentration (Cmax) of Voxelotor in Whole Blood
Measured: pre-dose, 2, 8, 24, 48, 96, 168 and 336 hours post-dose
Part A: Area Under the Concentration-Time Curve (AUC) From Time 0 to the Time of the Last Quantifiable Concentration (AUC0-last) of Voxelotor in Whole Blood
AUC0-last was calculated using the linear/log trapezoid rule.
Measured: pre-dose, 2, 8, 24, 48, 96, 168 and 336 hours post-dose
Part A: Area Under the Concentration-Time Curve (AUC) From Time 0 Extrapolated to Infinity (AUC0-inf) of Voxelotor in Whole Blood
AUC0-inf was calculated as AUCt + Ct/lambdaz, where AUCt=area under the concentration-time curve at designated time, Ct is the last quantifiable concentration for whole blood and lambdaz=elimination rate constant.
Measured: pre-dose, 2, 8, 24, 48, 96,168 and 336 hours post-dose
Part B: Change From Baseline to Week 24 in Hemoglobin Level
Measured: Baseline, Week 24
Part C: Change From Baseline to Week 48 in Cerebral Blood Flow
Cerebral blood flow was measured using transcranial Doppler (TCD) sonography. Change from baseline in cerebral blood flow as measured by the time-averaged mean of the maximum (TAMM) TCD velocity is reported.
Measured: Baseline, Week 48
Part D: Number of Participants With Treatment Emergent Adverse Events (TEAEs) and Serious Adverse Events (SAEs)
An adverse event (AE) was defined as any untoward medical occurrence in a participant administered a pharmaceutical product during the course of a clinical investigation. TEAE was defined as an AE that emerged on or after initiation of study drug (having been absent pre-treatment), or an AE that existed pre-treatment and worsened on treatment (relative to the pre-treatment state) through 28 days after study drug discontinuation. An SAE was any AE that resulted in any of the following outcomes: death, life threatening adverse drug experience, inpatient hospitalization or prolongation of existing hospitalization, persistent or significant disability or incapacity, congenital anomaly or birth defect, other important medical events. AEs were classified as SCD-related and non-SCD related.
Measured: From start of study treatment up to 28 days after study treatment discontinuation (Up to 52 weeks)
Secondary outcomes (48)
Part A: Maximum Concentration (Cmax) of Voxelotor in Plasma
Measured: pre-dose, 2, 8, 24, 48, 96, 168 and 336 hours post-dose
Part A: Maximum Concentration (Cmax) of Voxelotor in Red Blood Cells (RBC)
Measured: pre-dose, 2, 8, 24, 48, 96, 168 and 336 hours post-dose
Part A: Area Under the Concentration-Time Curve (AUC) From Time 0 to the Time of the Last Quantifiable Concentration (AUC0-last) of Voxelotor in Plasma
AUC0-last was calculated using the linear/log trapezoid rule.
Measured: pre-dose, 2, 8, 24, 48, 96, 168 and 336 hours post-dose
Part A: Area Under the Concentration-Time Curve (AUC) From Time 0 to the Time of the Last Quantifiable Concentration (AUC0-last) of Voxelotor in RBC
AUC0-last was calculated using the linear/log trapezoid rule.
Measured: pre-dose, 2, 8, 24, 48, 96, 168 and 336 hours post-dose
Part A: Area Under the Concentration-Time Curve (AUC) From Time 0 Extrapolated to Infinity (AUC0-inf) of Voxelotor in Plasma
AUC0-inf was calculated as AUCt + Ct/lambdaz, where AUCt=area under the concentration-time curve at designated time, Ct is the last quantifiable concentration for plasma and lambdaz is the elimination rate constant.
Measured: pre-dose, 2, 8, 24, 48, 96, 168 and 336 hours post-dose
Part A: Area Under the Concentration-Time Curve (AUC) From Time 0 Extrapolated to Infinity (AUC0-inf) of Voxelotor in RBC
AUC0-inf was calculated as AUCt + Ct/lambdaz, where AUCt=area under the concentration-time curve at designated time, Ct is the last quantifiable concentration and lambdaz is the elimination rate constant.
Measured: pre-dose, 2, 8, 24, 48, 96, 168 and 336 hours post-dose
Part A: Time at Which Cmax Was Observed (Tmax) for Voxelotor in Whole Blood
Measured: pre-dose, 2, 8, 24, 48, 96, 168 and 336 hours post-dose
Part A: Time at Which Cmax Was Observed (Tmax) for Voxelotor in Plasma
Measured: pre-dose, 2, 8, 24, 48, 96, 168 and 336 hours post-dose
Part A: Time at Which Cmax Was Observed (Tmax) for Voxelotor in RBC
Measured: pre-dose, 2, 8, 24, 48, 96, 168 and 336 hours post-dose
Part A: Terminal Elimination Half-Life (T1/2) for Voxelotor in Whole Blood
T1/2 was the time measured for the drug concentration to decrease by one half.
Measured: pre-dose, 2, 8, 24, 48, 96, 168 and 336 hours post-dose
Part A: Terminal Elimination Half-Life (T1/2) for Voxelotor in Plasma
T1/2 was the time measured for the drug concentration to decrease by one half.
Measured: pre-dose, 2, 8, 24, 48, 96, 168 and 336 hours post-dose
Part A: Terminal Elimination Half-Life (T1/2) for Voxelotor in RBC
T1/2 was the time measured for the drug concentration to decrease by one half.
Measured: pre-dose, 2, 8, 24, 48, 96, 168 and 336 hours post-dose
Part A: Percentage Hemoglobin (Hb) Occupancy
Percentage hemoglobin occupancy (% Hb Occupancy) refers to the percentage of hemoglobin molecules within red blood cells that were bound to study drug. Concentration of voxelotor in whole blood and plasma was used to calculate %Hb occupancy. Percentage Hb occupancy within RBCs was estimated using the formula:
([Concentration of voxelotor in whole blood- {1-hematocrit}]*[Concentration of voxelotor in plasma/hematocrit])/5000*100.
Measured: 15 days
Part B: Percentage of Days With SCD Symptom Exacerbation During the First 24 Weeks of Treatment
SCD symptoms were measured using the Patient Reported Outcome (PRO), Sickle Cell Disease Severity Measure (SCDSM) which was a self-administered 9-item questionnaire of SCD core symptoms including pain severity, frequency, and type, as well as fatigue and mental acuity, on a 4-point response scale that was completed daily using a handheld electronic device by the participants.
Measured: From Day 1 up to 24 weeks
Part B: Change From Baseline to Week 21 to 24 in the Sickle Cell Disease Severity Measure (SCDSM) Total Symptom Score (TSS)
The SCDSM was a self-administered 9-item questionnaire of SCD core symptoms including pain severity, frequency, and type, as well as fatigue and mental acuity, on a 4-point response scale with a range of 0 (strongly disagree) to 4 (strongly agree) that was completed daily using a handheld electronic device by the participants. TSS was calculated as the sum of the 9-item questionnaire scores scaled to a 100-point scale with a range of 0 (no symptoms) to 100 (most severe symptoms). Baseline TSS was the average of the non-missing score during the Screening period. The average of change from baseline in SCDSM TSS score for the 4-week period (Week 21 to 24) is reported.
Measured: Baseline, Weeks 21 to 24
Part B: Percent Change From Baseline to Weeks 12 and 24 in Lactate Dehydrogenase (LDH)
Measured: Baseline, Weeks 12 and 24
Part B: Percent Change From Baseline to Weeks 12 and 24 in Indirect Bilirubin
Measured: Baseline, Weeks 12 and 24
Part B: Percent Change From Baseline to Weeks 12 and 24 in Percentage Reticulocytes
Measured: Baseline, Weeks 12 and 24
Part B: Cmax of Voxelotor in Whole Blood and Plasma
Measured: Day 1 (pre-dose, 2, 8, 24 hours post-dose), pre-dose on Weeks 2, 4, 8, 12, 16, 20 and 24
Part B: Area Under the Concentration-Time Curve (AUC) From Time 0 Extrapolated to Infinity (AUC0-inf) of Voxelotor for Whole Blood and Plasma
AUC0-inf was calculated as AUCt + Ct/lambdaz, where AUCt=area under the concentration-time curve at designated time, Ct is the last quantifiable concentration and lambdaz is the elimination rate constant.
Measured: Day 1 (pre-dose, 2, 8, 24 hours post-dose), pre-dose on Weeks 2, 4, 8, 12, 16, 20 and 24
Part B: Terminal Elimination Half-life of Voxelotor for Plasma and Whole Blood
T1/2 was the time measured for the drug concentration to decrease by one half.
Measured: Day 1 (pre-dose, 2, 8, 24 hours post-dose), pre-dose on Weeks 2, 4, 8, 12, 16, 20 and 24
Part B: Accumulation Ratio (Rac) of Voxelotor for Plasma and Whole Blood
Accumulation ratio was calculated as ratio of area under the concentration-time curve from time 0 to 24 hours (AUC0-24) at steady-state (Day 28) to AUC0-24 on Day 1.
Measured: Day 1 (0 to 24 hours post-dose) and Day 28 (0 to 24 hours post-dose)
Part B: Percentage Hemoglobin Occupancy
Percentage hemoglobin occupancy (% Hb Occupancy) refers to the percentage of hemoglobin molecules within red blood cells that were bound to study drug. Concentration of voxelotor in whole blood and plasma was used to calculate %Hb occupancy. Percentage Hb occupancy within RBCs was estimated using the formula:
([Concentration of voxelotor in whole blood- {1-hematocrit}]*[Concentration of voxelotor in plasma/hematocrit])/5000*100.
Measured: Day 28
Part B: Change From Baseline to Week 12 and 24 in Cerebral Blood Flow
Cerebral blood flow was measured using TCD sonography. Change from baseline in cerebral blood flow as measured by TAMM TCD velocity is reported.
Measured: Baseline, Weeks 12 and 24
Part C: Change From Baseline to Weeks 24 and 48 in Hemoglobin Level
Measured: Baseline, Weeks 24 and 48
Part C: Percent Change From Baseline to Weeks 24 and 48 in LDH
Measured: Baseline, Weeks 24 and 48
Part C: Percent Change From Baseline to Weeks 24 and 48 in Indirect Bilirubin
Measured: Baseline, Weeks 24 and 48
Part C: Percent Change From Baseline to Weeks 24 and 48 in Percentage Reticulocytes
Measured: Baseline, Weeks 24 and 48
Part C: Change From Baseline to Week 24 in Cerebral Blood Flow
Cerebral blood flow was measured using TCD sonography. Change from baseline in cerebral blood flow as measured by TAMM TCD velocity is reported.
Measured: Baseline, Week 24
Part C: Time to Initial Hemoglobin Response
Time to initial Hb response was defined as the time from first dose of study treatment to the first occurrence of a change from baseline in Hb > 1 gram per deciliter (g/dL).
Measured: From first dose of study treatment (Day 1) up to Week 48
Part C: Cmax of Voxelotor for Plasma and Whole Blood
Measured: Day 1 (15 minutes to 2 hours post-dose), pre-dose on Weeks 4, 8, 12, 16, 20, 24, 36 and 48
Part C: Area Under the Concentration-Time Curve (AUC) From Time 0 Extrapolated to Infinity (AUC0-inf) of Voxelotor for Whole Blood and Plasma
AUC0-inf was calculated as AUCt + Ct/lambdaz, where AUCt=area under the concentration-time curve at designated time, Ct is the last quantifiable concentration and lambdaz is the elimination rate constant.
Measured: Day 1 (15 minutes to 2 hours post-dose), pre-dose on Weeks 4, 8, 12, 16, 20, 24, 36 and 48
Part C: Terminal Elimination Half-life (T1/2) of Voxelotor for Whole Blood and Plasma
T1/2 was the time measured for the drug concentration to decrease by one half.
Measured: Day 1 (15 minutes to 2 hours post-dose), pre-dose on Weeks 4, 8, 12, 16, 20, 24, 36 and 48
Part C: Percentage Hemoglobin Occupancy of Voxelotor
Percentage hemoglobin occupancy (% Hb Occupancy) refers to the percentage of hemoglobin molecules within red blood cells that were bound to study drug. Concentration of voxelotor in whole blood and plasma was used to calculate %Hb occupancy. Percentage Hb occupancy within RBCs was estimated using the formula:
([Concentration of voxelotor in whole blood- {1-hematocrit}]*[Concentration of voxelotor in plasma/hematocrit])/5000*100.
Measured: Day 28
Part C: Percentage of Participants With Normal Transcranial Doppler (TCD) Flow Velocity at Week 48
Normal TCD flow velocity was considered as < 170 centimeter per second (cm/sec) by non-imagining TCD or < 155 cm/sec by imaging transcranial Doppler (TCDi). Percentage of participants with normal TCD flow velocity at Week 48 by Baseline TCD group (i.e. Baseline normal TCD [<170 cm/sec] and Baseline conditional TCD [>=170 cm/sec] is reported.
Measured: Week 48
Part C: Annualized Incidence Rate of Vaso-occlusive Crisis (VOC) Events
VOC events included preferred terms of sickle cell anaemia with crisis, acute chest syndrome, pneumonia necrotising and pneumonia. Annualized incidence rate was calculated as total number of events divided by total person years. Total person years=sum of participants treatment period in years, which covered the time from first dose to last dose.
Measured: Up to Week 48
Part C: Annualized Incidence Rate of Stroke Events
Annualized incidence rate was calculated as total number of events divided by total person years. Total person years=sum of participants treatment period in years, which covered the time from first dose to last dose.
Measured: Up to Week 48
Part D: Cmax of Voxelotor for Plasma and Whole Blood
Measured: Day 1 (anytime between 15 minutes to 2 hours post-dose), pre-dose on Weeks 2, 8, 12, 16, 24, 36 and 48
Part D: Area Under the Concentration-Time Curve (AUC) From Time 0 Extrapolated to Infinity (AUC0-inf) of Voxelotor for Plasma and Whole Blood
AUC0-inf was calculated as AUCt + Ct/lambdaz, where AUCt=area under the concentration-time curve at designated time, Ct is the last quantifiable concentration and lambdaz is the elimination rate constant.
Measured: Day 1 (anytime between 15 minutes to 2 hours post-dose), pre-dose on Weeks 2, 8, 12, 16, 24, 36 and 48
Part D: T1/2 of Voxelotor for Plasma and Whole Blood
T1/2 was the time measured for the drug concentration to decrease by one half.
Measured: Day 1 (anytime between 15 minutes to 2 hours post-dose), pre-dose on Weeks 2, 8, 12, 16, 24, 36 and 48
Part D: Percentage Hemoglobin Occupancy
Percentage hemoglobin occupancy (% Hb Occupancy) refers to the percentage of hemoglobin molecules within red blood cells that were bound to study drug. Concentration of voxelotor in whole blood and plasma was used to calculate %Hb occupancy. Percentage Hb occupancy within RBCs was estimated using the formula:
([Concentration of voxelotor in whole blood- {1-hematocrit}]*[Concentration of voxelotor in plasma/hematocrit])/5000*100.
Measured: Day 28
Part D: Change From Baseline to Weeks 24 and 48 in Hemoglobin Level
Measured: Baseline, Weeks 24 and 48
Part D: Percent Change From Baseline to Weeks 24 and 48 in LDH
Measured: Baseline, Weeks 24 and 48
Part D: Percent Change From Baseline to Weeks 24 and 48 in Indirect Bilirubin
Measured: Baseline, Weeks 24 and 48
Part D: Percent Change From Baseline to Weeks 24 and 48 in Reticulocytes Count
Measured: Baseline, Weeks 24 and 48
Part D: Time to Initial Hemoglobin Response
Time to initial Hb response, defined as the time from first dose of study treatment to the first occurrence of a change from baseline in Hb > 1 g/dL.
Measured: From first dose of study treatment (Day 1) up to Week 48
Part D: Annualized Incidence Rate of VOC Events
VOC events included preferred terms of 'Sickle cell anemia with crisis', 'Acute chest syndrome', 'Pneumonia necrotising,' and 'Pneumonia. Annualized incidence rate was calculated as total number of events divided by total person years. Total person years=sum of participants treatment period in years, which covered the time from first dose to last dose.
Measured: Up to Week 48
Part D: Annualized Incidence Rate of Stroke Events
Annualized incidence rate was calculated as total number of events divided by total person years. Total person years=sum of participants treatment period in years, which covered the time from first dose to last dose.
Measured: Up to Week 48
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 Aug 2016 (estimated)
- Study start5 Jul 2016
- Primary completion2 Oct 2023
- Study completion2 Oct 2023
Why it stopped: Emerging clinical data evaluated by Pfizer and shared with regulatory authorities indicates that the risk profile of voxelotor in people with SCD exceeds the benefits observed in previously generated global research and requires further assessment.
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.
- Publications (1)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 PfizerThe 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
- Phase 2
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Sequential
- Masking
- None (open label)
- Enrolment
- 147 participants (actual)
Sponsor and investigators
- Lead sponsor
- Pfizer
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Pfizer CT.gov Call Center, Study director, Pfizer
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02850406
- Sponsor's protocol ID
- GBT440-007
- Other IDs
- C5341020
- Acronym
- HOPE-KIDS
- Status last verified
- Jul 2025
- First submitted
- 1 Jul 2016
- Last updated
- 15 Aug 2025
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: 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.
- Expanded access
- Available
Publications
Estepp JH, Kalpatthi R, Woods G, Trompeter S, Liem RI, Sims K, Inati A, Inusa BPD, Campbell A, Piccone C, Abboud MR, Smith-Whitley K, Dixon S, Tonda M, Washington C, Griffin NM, Brown C. Safety and efficacy of voxelotor in pediatric patients with sickle cell disease aged 4 to 11 years. Pediatr Blood Cancer. 2022 Aug;69(8):e29716. doi: 10.1002/pbc.29716. Epub 2022 Apr 21.
PubMed 35451176
Study at a glance
From the registry record, last updated by the sponsor on 15 Aug 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase 2a, Open-label, Single and Multiple Dose Study to Evaluate the Pharmacokinetics, Safety, Tolerability and Treatment Effect of GBT440 in Pediatric Participants With Sickle Cell Disease
- ClinicalTrials.gov ID
- NCT02850406
- Acronym / sponsor ID
- HOPE-KIDS / GBT440-007
- Conditions
- Sickle Cell Disease
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- TerminatedReason stopped: Emerging clinical data evaluated by Pfizer and shared with regulatory authorities indicates that the risk profile of voxelotor in people with SCD exceeds the benefits observed in previously generated global research and requires further assessment.
- Enrolment
- 147 participants (actual)
- Lead sponsor
- PfizerIndustry (pharma, biotech, devices)
- Study start
- 5 Jul 2016 (actual)
- Primary completion
- 2 Oct 2023 (actual)
- Study completion
- 2 Oct 2023 (actual)
- First posted
- 1 Aug 2016 (estimated)
- Results
- Posted 15 Aug 2025
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study consists of four parts, Parts A, B, C, and D.
- Part A is a single dose pharmacokinetic (PK) study in pediatric participants with Sickle Cell Disease ages 6 to 17 years.
- Part B is a multiple dose, safety, exploratory, efficacy, and PK study in adolescent participants with Sickle Cell Disease ages 12 to 17 years.
- Part C is a multiple dose, safety, tolerability, and PK study, which includes the assessment of hematological effects and the effect on TCD flow velocity of voxelotor in pediatric participants with Sickle Cell Disease ages 4 to 17 years.
- Part D is a multiple dose, safety, tolerability, and PK study, which examines the hematological effects of voxelotor in pediatric participants with Sickle Cell Disease ages 6 months to < 4 years.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Sequential
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Voxelotor | Experimental | Drug: VoxelotorSubjects to receive daily oral dosing of voxelotor according to which Part (A, B, C, or D), the subject is participating in: * Part A: Subjects to receive daily oral dosing of voxelotor for 1 day (single dose) * Part B: Subjects to receive daily oral dosing of voxelotor for up to 24 weeks (multiple dose) * Part C: Subjects to receive daily oral dosing of voxelotor for up to 48 weeks (1500mg or 1500mg equivalent dose) * Part D: Subjects to receive daily oral dosing of voxelotor for up to 48 weeks (1500mg equivalent dose) |
Who may qualify
- Ages
- 6 months to 17 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child
Key inclusion criteria (13 listed)
- Male or female participants with homozygous hemoglobin SS (HbSS) or hemoglobin S beta0 thalassemia (HbS β0thal)
- Age:
- Hydroxyurea (HU) therapy:
- Hemoglobin (HB):
- For Part C only: Participants 12 to 17 years of age must have a TCD velocity of ≥ 140 cm/sec measured anytime during screening.
Key exclusion criteria (9 listed)
- Any one of the following requiring medical attention within 14 days of signing the Informed Consent Form (ICF):
- Requires chronic transfusion therapy
- History of stroke or meeting criteria for primary stroke prophylaxis (history of two TCD measurements ≥ 200 cm/sec by non-imaging TCD or ≥185 cm/sec by TCDi).
- Transfusion within 30 days prior to signing the ICF
- Body weight <5 kg for 1 month prior to the screening visit and at the screening visit.
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 |
|---|---|---|
| Voxelotor* Part A: Voxelotor will be administered as oral capsules or tablets * Part B: Voxelotor will be administered as oral capsules or tablets * Part C: Voxelotor will be administered as oral dispersible tablets or powder for oral suspension * Part D: Voxelotor will be administered as oral dispersible tablets or powder for oral suspension | Drug | Voxelotor |
Primary outcome
Part A: Maximum Concentration (Cmax) of Voxelotor in Whole Blood
Time frame: pre-dose, 2, 8, 24, 48, 96, 168 and 336 hours post-dose
Part A: Area Under the Concentration-Time Curve (AUC) From Time 0 to the Time of the Last Quantifiable Concentration (AUC0-last) of Voxelotor in Whole Blood
Time frame: pre-dose, 2, 8, 24, 48, 96, 168 and 336 hours post-dose
AUC0-last was calculated using the linear/log trapezoid rule.
Part A: Area Under the Concentration-Time Curve (AUC) From Time 0 Extrapolated to Infinity (AUC0-inf) of Voxelotor in Whole Blood
Time frame: pre-dose, 2, 8, 24, 48, 96,168 and 336 hours post-dose
AUC0-inf was calculated as AUCt + Ct/lambdaz, where AUCt=area under the concentration-time curve at designated time, Ct is the last quantifiable concentration for whole blood and lambdaz=elimination rate constant.
Part B: Change From Baseline to Week 24 in Hemoglobin Level
Time frame: Baseline, Week 24
Part C: Change From Baseline to Week 48 in Cerebral Blood Flow
Time frame: Baseline, Week 48
Cerebral blood flow was measured using transcranial Doppler (TCD) sonography. Change from baseline in cerebral blood flow as measured by the time-averaged mean of the maximum (TAMM) TCD velocity is reported.
Part D: Number of Participants With Treatment Emergent Adverse Events (TEAEs) and Serious Adverse Events (SAEs)
Time frame: From start of study treatment up to 28 days after study treatment discontinuation (Up to 52 weeks)
An adverse event (AE) was defined as any untoward medical occurrence in a participant administered a pharmaceutical product during the course of a clinical investigation. TEAE was defined as an AE that emerged on or after initiation of study drug (having been absent pre-treatment), or an AE that existed pre-treatment and worsened on treatment (relative to the pre-treatment state) through 28 days after study drug discontinuation. An SAE was any AE that resulted in any of the following outcomes: death, life threatening adverse drug experience, inpatient hospitalization or prolongation of existing hospitalization, persistent or significant disability or incapacity, congenital anomaly or birth defect, other important medical events. AEs were classified as SCD-related and non-SCD related.
48 secondary outcomes
Part A: Maximum Concentration (Cmax) of Voxelotor in Plasma
Time frame: pre-dose, 2, 8, 24, 48, 96, 168 and 336 hours post-dose
Part A: Maximum Concentration (Cmax) of Voxelotor in Red Blood Cells (RBC)
Time frame: pre-dose, 2, 8, 24, 48, 96, 168 and 336 hours post-dose
Part A: Area Under the Concentration-Time Curve (AUC) From Time 0 to the Time of the Last Quantifiable Concentration (AUC0-last) of Voxelotor in Plasma
Time frame: pre-dose, 2, 8, 24, 48, 96, 168 and 336 hours post-dose
Part A: Area Under the Concentration-Time Curve (AUC) From Time 0 to the Time of the Last Quantifiable Concentration (AUC0-last) of Voxelotor in RBC
Time frame: pre-dose, 2, 8, 24, 48, 96, 168 and 336 hours post-dose
Part A: Area Under the Concentration-Time Curve (AUC) From Time 0 Extrapolated to Infinity (AUC0-inf) of Voxelotor in Plasma
Time frame: pre-dose, 2, 8, 24, 48, 96, 168 and 336 hours post-dose
Part A: Area Under the Concentration-Time Curve (AUC) From Time 0 Extrapolated to Infinity (AUC0-inf) of Voxelotor in RBC
Time frame: pre-dose, 2, 8, 24, 48, 96, 168 and 336 hours post-dose
Part A: Time at Which Cmax Was Observed (Tmax) for Voxelotor in Whole Blood
Time frame: pre-dose, 2, 8, 24, 48, 96, 168 and 336 hours post-dose
Part A: Time at Which Cmax Was Observed (Tmax) for Voxelotor in Plasma
Time frame: pre-dose, 2, 8, 24, 48, 96, 168 and 336 hours post-dose
Part A: Time at Which Cmax Was Observed (Tmax) for Voxelotor in RBC
Time frame: pre-dose, 2, 8, 24, 48, 96, 168 and 336 hours post-dose
Part A: Terminal Elimination Half-Life (T1/2) for Voxelotor in Whole Blood
Time frame: pre-dose, 2, 8, 24, 48, 96, 168 and 336 hours post-dose
Part A: Terminal Elimination Half-Life (T1/2) for Voxelotor in Plasma
Time frame: pre-dose, 2, 8, 24, 48, 96, 168 and 336 hours post-dose
Part A: Terminal Elimination Half-Life (T1/2) for Voxelotor in RBC
Time frame: pre-dose, 2, 8, 24, 48, 96, 168 and 336 hours post-dose
Part A: Percentage Hemoglobin (Hb) Occupancy
Time frame: 15 days
Part B: Percentage of Days With SCD Symptom Exacerbation During the First 24 Weeks of Treatment
Time frame: From Day 1 up to 24 weeks
Part B: Change From Baseline to Week 21 to 24 in the Sickle Cell Disease Severity Measure (SCDSM) Total Symptom Score (TSS)
Time frame: Baseline, Weeks 21 to 24
Part B: Percent Change From Baseline to Weeks 12 and 24 in Lactate Dehydrogenase (LDH)
Time frame: Baseline, Weeks 12 and 24
Part B: Percent Change From Baseline to Weeks 12 and 24 in Indirect Bilirubin
Time frame: Baseline, Weeks 12 and 24
Part B: Percent Change From Baseline to Weeks 12 and 24 in Percentage Reticulocytes
Time frame: Baseline, Weeks 12 and 24
Part B: Cmax of Voxelotor in Whole Blood and Plasma
Time frame: Day 1 (pre-dose, 2, 8, 24 hours post-dose), pre-dose on Weeks 2, 4, 8, 12, 16, 20 and 24
Part B: Area Under the Concentration-Time Curve (AUC) From Time 0 Extrapolated to Infinity (AUC0-inf) of Voxelotor for Whole Blood and Plasma
Time frame: Day 1 (pre-dose, 2, 8, 24 hours post-dose), pre-dose on Weeks 2, 4, 8, 12, 16, 20 and 24
Part B: Terminal Elimination Half-life of Voxelotor for Plasma and Whole Blood
Time frame: Day 1 (pre-dose, 2, 8, 24 hours post-dose), pre-dose on Weeks 2, 4, 8, 12, 16, 20 and 24
Part B: Accumulation Ratio (Rac) of Voxelotor for Plasma and Whole Blood
Time frame: Day 1 (0 to 24 hours post-dose) and Day 28 (0 to 24 hours post-dose)
Part B: Percentage Hemoglobin Occupancy
Time frame: Day 28
Part B: Change From Baseline to Week 12 and 24 in Cerebral Blood Flow
Time frame: Baseline, Weeks 12 and 24
Part C: Change From Baseline to Weeks 24 and 48 in Hemoglobin Level
Time frame: Baseline, Weeks 24 and 48
Part C: Percent Change From Baseline to Weeks 24 and 48 in LDH
Time frame: Baseline, Weeks 24 and 48
Part C: Percent Change From Baseline to Weeks 24 and 48 in Indirect Bilirubin
Time frame: Baseline, Weeks 24 and 48
Part C: Percent Change From Baseline to Weeks 24 and 48 in Percentage Reticulocytes
Time frame: Baseline, Weeks 24 and 48
Part C: Change From Baseline to Week 24 in Cerebral Blood Flow
Time frame: Baseline, Week 24
Part C: Time to Initial Hemoglobin Response
Time frame: From first dose of study treatment (Day 1) up to Week 48
Part C: Cmax of Voxelotor for Plasma and Whole Blood
Time frame: Day 1 (15 minutes to 2 hours post-dose), pre-dose on Weeks 4, 8, 12, 16, 20, 24, 36 and 48
Part C: Area Under the Concentration-Time Curve (AUC) From Time 0 Extrapolated to Infinity (AUC0-inf) of Voxelotor for Whole Blood and Plasma
Time frame: Day 1 (15 minutes to 2 hours post-dose), pre-dose on Weeks 4, 8, 12, 16, 20, 24, 36 and 48
Part C: Terminal Elimination Half-life (T1/2) of Voxelotor for Whole Blood and Plasma
Time frame: Day 1 (15 minutes to 2 hours post-dose), pre-dose on Weeks 4, 8, 12, 16, 20, 24, 36 and 48
Part C: Percentage Hemoglobin Occupancy of Voxelotor
Time frame: Day 28
Part C: Percentage of Participants With Normal Transcranial Doppler (TCD) Flow Velocity at Week 48
Time frame: Week 48
Part C: Annualized Incidence Rate of Vaso-occlusive Crisis (VOC) Events
Time frame: Up to Week 48
Part C: Annualized Incidence Rate of Stroke Events
Time frame: Up to Week 48
Part D: Cmax of Voxelotor for Plasma and Whole Blood
Time frame: Day 1 (anytime between 15 minutes to 2 hours post-dose), pre-dose on Weeks 2, 8, 12, 16, 24, 36 and 48
Part D: Area Under the Concentration-Time Curve (AUC) From Time 0 Extrapolated to Infinity (AUC0-inf) of Voxelotor for Plasma and Whole Blood
Time frame: Day 1 (anytime between 15 minutes to 2 hours post-dose), pre-dose on Weeks 2, 8, 12, 16, 24, 36 and 48
Part D: T1/2 of Voxelotor for Plasma and Whole Blood
Time frame: Day 1 (anytime between 15 minutes to 2 hours post-dose), pre-dose on Weeks 2, 8, 12, 16, 24, 36 and 48
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 15 Aug 2025.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Derived from this study: PubMed 35451176Estepp JH, Kalpatthi R, Woods G, Trompeter S, Liem RI, Sims K, Inati A, Inusa BPD, Campbell A, Piccone C, Abboud MR, Smith-Whitley K, Dixon S, Tonda M, Washington C, Griffin NM, Brown C. Safety and efficacy of voxelotor in pediatric patients with sickle cell disease aged 4 to 11 years. Pediatr Blood Cancer. 2022 Aug;69(8):e29716. doi: 10.1002/pbc.29716. Epub 2022 Apr 21.
- To obtain contact information for a study center near you, click here.Link provided by the sponsor.
- Individual participant dataSharing planned: Yes. 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.
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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.
Pfizer CT.gov Call Center study director
Pfizer
20 sites in 3 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing Voxelotor in people with Sickle Cell Disease, run by Pfizer at 20 sites in 3 countries.
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 13 inclusion and 9 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 15 Aug 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 20 sites in United States, United Kingdom, Lebanon. 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?
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 15 Aug 2025). 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?
Part A: Maximum Concentration (Cmax) of Voxelotor in Whole Blood (time frame: pre-dose, 2, 8, 24, 48, 96, 168 and 336 hours post-dose). The study lists 6 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 NCT02850406, which also lists 1 linked publication.
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 15 Aug 2025.