Purpose

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.

Condition

Eligibility

Eligible Ages
Between 6 Months and 17 Years
Eligible Genders
All
Accepts Healthy Volunteers
No

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

Phase
Phase 2
Study Type
Interventional
Allocation
N/A
Intervention Model
Sequential Assignment
Primary Purpose
Treatment
Masking
None (Open Label)

Arm Groups

ArmDescriptionAssigned Intervention
Experimental
Voxelotor
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)
  • Drug: 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

Recruiting Locations

More Details

NCT ID
NCT02850406
Status
Active, not recruiting
Sponsor
Pfizer

Notice

Study information shown on this site is derived from ClinicalTrials.gov (a public registry operated by the National Institutes of Health). The listing of studies provided is not certain to be all studies for which you might be eligible. Furthermore, study eligibility requirements can be difficult to understand and may change over time, so it is wise to speak with your medical care provider and individual research study teams when making decisions related to participation.