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Study to Evaluate the Effect of GBT440 in Pediatrics With Sickle Cell Disease

Phase 2
Terminated
Conditions
Sickle Cell Disease
Interventions
Registration Number
NCT02850406
Lead Sponsor
Pfizer
Brief 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.

* 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.

Detailed Description

Not available

Recruitment & Eligibility

Status
TERMINATED
Sex
All
Target Recruitment
147
Inclusion Criteria
  • 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
  • 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.

Exclusion Criteria
  • 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

  • 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

Exclusion Criteria for Part D Only:

  • Body weight <5 kg for 1 month prior to the screening visit and at the screening visit.

Study & Design

Study Type
INTERVENTIONAL
Study Design
SEQUENTIAL
Arm && Interventions
GroupInterventionDescription
VoxelotorVoxelotorSubjects 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)
Primary Outcome Measures
NameTimeMethod
Part A: Area Under the Concentration-Time Curve (AUC) From Time 0 Extrapolated to Infinity (AUC0-inf) of Voxelotor in Whole Bloodpre-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 D: Number of Participants With Treatment Emergent Adverse Events (TEAEs) and Serious Adverse Events (SAEs)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.

Part A: Maximum Concentration (Cmax) of Voxelotor in Whole Bloodpre-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 Bloodpre-dose, 2, 8, 24, 48, 96, 168 and 336 hours post-dose

AUC0-last was calculated using the linear/log trapezoid rule.

Part B: Change From Baseline to Week 24 in Hemoglobin LevelBaseline, Week 24
Part C: Change From Baseline to Week 48 in Cerebral Blood FlowBaseline, 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.

Secondary Outcome Measures
NameTimeMethod
Part A: Maximum Concentration (Cmax) of Voxelotor in Red Blood Cells (RBC)pre-dose, 2, 8, 24, 48, 96, 168 and 336 hours post-dose
Part C: Percent Change From Baseline to Weeks 24 and 48 in Indirect BilirubinBaseline, Weeks 24 and 48
Part A: Area Under the Concentration-Time Curve (AUC) From Time 0 Extrapolated to Infinity (AUC0-inf) of Voxelotor in Plasmapre-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 plasma and lambdaz is the elimination rate constant.

Part A: Time at Which Cmax Was Observed (Tmax) for Voxelotor in Plasmapre-dose, 2, 8, 24, 48, 96, 168 and 336 hours post-dose
Part A: Terminal Elimination Half-Life (T1/2) for Voxelotor in Whole Bloodpre-dose, 2, 8, 24, 48, 96, 168 and 336 hours post-dose

T1/2 was the time measured for the drug concentration to decrease by one half.

Part A: Terminal Elimination Half-Life (T1/2) for Voxelotor in Plasmapre-dose, 2, 8, 24, 48, 96, 168 and 336 hours post-dose

T1/2 was the time measured for the drug concentration to decrease by one half.

Part A: Maximum Concentration (Cmax) of Voxelotor in Plasmapre-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 Plasmapre-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 to the Time of the Last Quantifiable Concentration (AUC0-last) of Voxelotor in RBCpre-dose, 2, 8, 24, 48, 96, 168 and 336 hours post-dose

AUC0-last was calculated using the linear/log trapezoid rule.

Part B: Area Under the Concentration-Time Curve (AUC) From Time 0 Extrapolated to Infinity (AUC0-inf) of Voxelotor for Whole Blood and PlasmaDay 1 (pre-dose, 2, 8, 24 hours post-dose), pre-dose on Weeks 2, 4, 8, 12, 16, 20 and 24

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.

Part B: Terminal Elimination Half-life of Voxelotor for Plasma and Whole BloodDay 1 (pre-dose, 2, 8, 24 hours post-dose), pre-dose on Weeks 2, 4, 8, 12, 16, 20 and 24

T1/2 was the time measured for the drug concentration to decrease by one half.

Part B: Accumulation Ratio (Rac) of Voxelotor for Plasma and Whole BloodDay 1 (0 to 24 hours post-dose) and Day 28 (0 to 24 hours post-dose)

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.

Part D: T1/2 of Voxelotor for Plasma and Whole BloodDay 1 (anytime between 15 minutes to 2 hours post-dose), pre-dose on Weeks 2, 8, 12, 16, 24, 36 and 48

T1/2 was the time measured for the drug concentration to decrease by one half.

Part D: Time to Initial Hemoglobin ResponseFrom first dose of study treatment (Day 1) up to Week 48

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.

Part A: Area Under the Concentration-Time Curve (AUC) From Time 0 Extrapolated to Infinity (AUC0-inf) of Voxelotor in RBCpre-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 and lambdaz is the elimination rate constant.

Part A: Time at Which Cmax Was Observed (Tmax) for Voxelotor in Whole Bloodpre-dose, 2, 8, 24, 48, 96, 168 and 336 hours post-dose
Part A: Time at Which Cmax Was Observed (Tmax) for Voxelotor in RBCpre-dose, 2, 8, 24, 48, 96, 168 and 336 hours post-dose
Part A: Terminal Elimination Half-Life (T1/2) for Voxelotor in RBCpre-dose, 2, 8, 24, 48, 96, 168 and 336 hours post-dose

T1/2 was the time measured for the drug concentration to decrease by one half.

Part A: Percentage Hemoglobin (Hb) Occupancy15 days

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.

Part B: Percentage of Days With SCD Symptom Exacerbation During the First 24 Weeks of TreatmentFrom Day 1 up to 24 weeks

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.

Part B: Percent Change From Baseline to Weeks 12 and 24 in Lactate Dehydrogenase (LDH)Baseline, Weeks 12 and 24
Part B: Percent Change From Baseline to Weeks 12 and 24 in Percentage ReticulocytesBaseline, Weeks 12 and 24
Part B: Cmax of Voxelotor in Whole Blood and PlasmaDay 1 (pre-dose, 2, 8, 24 hours post-dose), pre-dose on Weeks 2, 4, 8, 12, 16, 20 and 24
Part B: Change From Baseline to Week 21 to 24 in the Sickle Cell Disease Severity Measure (SCDSM) Total Symptom Score (TSS)Baseline, Weeks 21 to 24

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.

Part B: Percent Change From Baseline to Weeks 12 and 24 in Indirect BilirubinBaseline, Weeks 12 and 24
Part B: Percentage Hemoglobin OccupancyDay 28

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.

Part C: Time to Initial Hemoglobin ResponseFrom first dose of study treatment (Day 1) up to Week 48

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).

Part B: Change From Baseline to Week 12 and 24 in Cerebral Blood FlowBaseline, Weeks 12 and 24

Cerebral blood flow was measured using TCD sonography. Change from baseline in cerebral blood flow as measured by TAMM TCD velocity is reported.

Part C: Percent Change From Baseline to Weeks 24 and 48 in LDHBaseline, Weeks 24 and 48
Part C: Annualized Incidence Rate of Vaso-occlusive Crisis (VOC) EventsUp to Week 48

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.

Part D: Cmax of Voxelotor for Plasma and Whole BloodDay 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 OccupancyDay 28

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.

Part D: Percent Change From Baseline to Weeks 24 and 48 in LDHBaseline, Weeks 24 and 48
Part D: Percent Change From Baseline to Weeks 24 and 48 in Indirect BilirubinBaseline, Weeks 24 and 48
Part D: Annualized Incidence Rate of Stroke EventsUp to Week 48

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.

Part C: Change From Baseline to Weeks 24 and 48 in Hemoglobin LevelBaseline, Weeks 24 and 48
Part C: Change From Baseline to Week 24 in Cerebral Blood FlowBaseline, Week 24

Cerebral blood flow was measured using TCD sonography. Change from baseline in cerebral blood flow as measured by TAMM TCD velocity is reported.

Part C: Cmax of Voxelotor for Plasma and Whole BloodDay 1 (15 minutes to 2 hours post-dose), pre-dose on Weeks 4, 8, 12, 16, 20, 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 BloodDay 1 (anytime between 15 minutes to 2 hours post-dose), pre-dose on Weeks 2, 8, 12, 16, 24, 36 and 48

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.

Part D: Change From Baseline to Weeks 24 and 48 in Hemoglobin LevelBaseline, Weeks 24 and 48
Part C: Percent Change From Baseline to Weeks 24 and 48 in Percentage ReticulocytesBaseline, Weeks 24 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 PlasmaDay 1 (15 minutes to 2 hours post-dose), pre-dose on Weeks 4, 8, 12, 16, 20, 24, 36 and 48

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.

Part C: Terminal Elimination Half-life (T1/2) of Voxelotor for Whole Blood and PlasmaDay 1 (15 minutes to 2 hours post-dose), pre-dose on Weeks 4, 8, 12, 16, 20, 24, 36 and 48

T1/2 was the time measured for the drug concentration to decrease by one half.

Part C: Percentage Hemoglobin Occupancy of VoxelotorDay 28

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.

Part C: Percentage of Participants With Normal Transcranial Doppler (TCD) Flow Velocity at Week 48Week 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.

Part C: Annualized Incidence Rate of Stroke EventsUp to Week 48

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.

Part D: Percent Change From Baseline to Weeks 24 and 48 in Reticulocytes CountBaseline, Weeks 24 and 48
Part D: Annualized Incidence Rate of VOC EventsUp to Week 48

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.

Trial Locations

Locations (20)

Brentwood Clinic UCSF Benioff Children's Hospital Oakland

🇺🇸

Brentwood, California, United States

Children's National Medical Center

🇺🇸

Washington, District of Columbia, United States

Children's Healthcare of Atlanta Scottish Rite

🇺🇸

Atlanta, Georgia, United States

Ann & Robert H. Lurie Children's Hospital of Chicago

🇺🇸

Chicago, Illinois, United States

University of Illinois at Chicago Clinical Research Center

🇺🇸

Chicago, Illinois, United States

Our Lady of the Lake Children's Hospital (IP Address)

🇺🇸

Baton Rouge, Louisiana, United States

Children's Mercy Hospital

🇺🇸

Kansas City, Missouri, United States

Rutgers-Robert Wood Johnson Medical School

🇺🇸

New Brunswick, New Jersey, United States

Brody School of Medicine at East Carolina University

🇺🇸

Greenville, North Carolina, United States

University Hospitals Cleveland Medical Center, Rainbow Babies & Children's Hospital

🇺🇸

Cleveland, Ohio, United States

Scroll for more (10 remaining)
Brentwood Clinic UCSF Benioff Children's Hospital Oakland
🇺🇸Brentwood, California, United States

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