Trial · NCT03036813

Study to Evaluate the Effect of Voxelotor Administered Orally to Patients With Sickle Cell Disease (GBT_HOPE)

NCT03036813, Phase 3, Completed, Pfizer; results first posted 2021-01-07

3 sourcestrials-2026-11-12-0.5.0

Cite this record

ConductScience Library. Study to Evaluate the Effect of Voxelotor Administered Orally to Patients With Sickle Cell Disease (GBT_HOPE). Trials, record NCT03036813. Release trials-2026-11-12-0.5.0, 12 Nov 2026. https://conductscience.org/library/trials/NCT03036813

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Trial

As registered on ClinicalTrials.gov, in the graph's capture of the registry.

Title: Study to Evaluate the Effect of Voxelotor Administered Orally to Patients With Sickle Cell Disease (GBT_HOPE)
NCT number: NCT03036813
Status: Completed
Phases: Phase 3
Enrollment: 449 participants, actual
Lead sponsor: Pfizer
Conditions: Sickle Cell Disease
Interventions: voxelotor, Placebo
First posted: 2017-01-30
Last updated: 2023-07-27
Results first posted: 2021-01-07

Source ClinicalTrials.gov

Registered outcomes6

Each outcome the trial registered, primary first, in ClinicalTrials.gov's words.

List	Outcome	Time frame	Description
Primary	Number of Participants With Increase in Hb >1 g/dL From Baseline to Week 24	Baseline to Week 24	Number of participants with increase in Hb \>1 g/dL from Baseline to Week 24
Secondary	Annualized Vaso-Occlusive Crisis (VOC) Incidence Rate	Baseline to Week 72	Number of Vaso-Occlusive Crisis (VOC) events averaged per year.
Secondary	Percentage Change From Baseline in Hemolysis Measures	Baseline to Week 24	Percentage change from Baseline to week 24 in unconjugated bilirubin
Secondary	Percentage Change From Baseline in Hemolysis Measures	Baseline to Week 24	Percentage change from Baseline to week 24 in the absolute reticulocyte which is used to estimate the degree of effective erythropoiesis. This values is important in Sickle Cell Disease and was reported by the central laboratory.
Secondary	Percentage Change From Baseline in Hemolysis Measures	Baseline to Week 24	Percentage change from Baseline to week 24 in reticulocytes % which is a % of total Red Blood Cells (RBCs).
Secondary	Percentage Change From Baseline in Hemolysis Measures	Baseline to Week 24	Percentage change from Baseline to week 24 in Lactate Dehydrogenase (LDH)

Source ClinicalTrials.gov

Outcomes6

Each outcome the trial posted results for, in ClinicalTrials.gov's words.

Type	Outcome	Time frame	Population	Units	Measured as
PRIMARY	Number of Participants With Increase in Hb >1 g/dL From Baseline to Week 24	Baseline to Week 24	All randomized subject (ITT population).	Participants	COUNT_OF_PARTICIPANTS
SECONDARY	Annualized Vaso-Occlusive Crisis (VOC) Incidence Rate	Baseline to Week 72	Population excludes 3 subjects (1 in the placebo group and 2 in the voxelotor 1500-mg group) who were not treated.	Events per year	MEAN
SECONDARY	Percentage Change From Baseline in Hemolysis Measures	Baseline to Week 24	Analysis population includes all randomized patients with a baseline value and at least one post-baseline value	percentage change	LEAST_SQUARES_MEAN
SECONDARY	Percentage Change From Baseline in Hemolysis Measures	Baseline to Week 24		percentage change	LEAST_SQUARES_MEAN
SECONDARY	Percentage Change From Baseline in Hemolysis Measures	Baseline to Week 24		Percentage Change	LEAST_SQUARES_MEAN
SECONDARY	Percentage Change From Baseline in Hemolysis Measures	Baseline to Week 24	Analysis population includes all randomized patients with a baseline value and at least one post-baseline value	Percentage Change	LEAST_SQUARES_MEAN

Source ClinicalTrials.gov

Results by group18

Each measurement the trial posted, group by group, in the words and numbers it posted.

Outcome	Group	Value	Spread	Units
Number of Participants With Increase in Hb >1 g/dL From Baseline to Week 24	Voxelotor 900 mg	30		Participants
Number of Participants With Increase in Hb >1 g/dL From Baseline to Week 24	Voxelotor 1500 mg	46		Participants
Number of Participants With Increase in Hb >1 g/dL From Baseline to Week 24	Placebo	6		Participants
Annualized Vaso-Occlusive Crisis (VOC) Incidence Rate	Voxelotor 900 mg	2.4	95% Confidence Interval 1.9 to 3.1	Events per year
Annualized Vaso-Occlusive Crisis (VOC) Incidence Rate	Voxelotor 1500 mg	2.4	95% Confidence Interval 1.8 to 3.1	Events per year
Annualized Vaso-Occlusive Crisis (VOC) Incidence Rate	Placebo	2.8	95% Confidence Interval 2.2 to 3.6	Events per year
Percentage Change From Baseline in Hemolysis Measures	Voxelotor 900 mg	-20.1	Standard Error 3.41	percentage change
Percentage Change From Baseline in Hemolysis Measures	Voxelotor 1500 mg	-29.1	Standard Error 3.46	percentage change
Percentage Change From Baseline in Hemolysis Measures	Placebo	-2.8	Standard Error 3.51	percentage change
Percentage Change From Baseline in Hemolysis Measures	Voxelotor 900 mg	4.7	Standard Error 5.13	percentage change

1 to 10 of 18Source ClinicalTrials.gov

See all 18 results by group

Participant flow9

How many started, completed or left each group, period by period.

Period	Milestone	Group	Participants
Overall Study	STARTED	Voxelotor 900mg	92
Overall Study	STARTED	Voxelotor 1500mg	90
Overall Study	STARTED	Placebo	92
Overall Study	COMPLETED	Voxelotor 900mg	70
Overall Study	COMPLETED	Voxelotor 1500mg	63
Overall Study	COMPLETED	Placebo	66
Overall Study	NOT COMPLETED	Voxelotor 900mg	22
Overall Study	NOT COMPLETED	Voxelotor 1500mg	27
Overall Study	NOT COMPLETED	Placebo	26

Source ClinicalTrials.gov

Adverse events321

Each adverse event the trial posted, group by group: the participants affected out of those at risk.

Type	Event	Organ system	Group	Affected	At risk	Events
other	Headache	Nervous system disorders	Voxelotor 900 mg	20	92	22
other	Headache	Nervous system disorders	Voxelotor 1500 mg	27	88	33
other	Headache	Nervous system disorders	Placebo	23	91	34
other	Diarrhoea	Gastrointestinal disorders	Voxelotor 900 mg	17	92	24
other	Diarrhoea	Gastrointestinal disorders	Voxelotor 1500 mg	20	88	22
other	Diarrhoea	Gastrointestinal disorders	Placebo	10	91	12
other	Arthralgia	Musculoskeletal and connective tissue disorders	Voxelotor 900 mg	14	92	24
other	Arthralgia	Musculoskeletal and connective tissue disorders	Voxelotor 1500 mg	18	88	33
other	Arthralgia	Musculoskeletal and connective tissue disorders	Placebo	13	91	17
other	Nausea	Gastrointestinal disorders	Voxelotor 900 mg	17	92	21

1 to 10 of 321Source ClinicalTrials.gov

See all 321 adverse events

Adverse event totals9

The totals the trial posted for each group.

Total	Group	Affected	At risk
Total, all-cause mortality	Voxelotor 900 mg	2	92
Total, all-cause mortality	Voxelotor 1500 mg	2	88
Total, all-cause mortality	Placebo	2	91
Total, other adverse events	Voxelotor 900 mg	85	92
Total, other adverse events	Voxelotor 1500 mg	85	88
Total, other adverse events	Placebo	81	91
Total, serious adverse events	Voxelotor 900 mg	20	92
Total, serious adverse events	Voxelotor 1500 mg	25	88
Total, serious adverse events	Placebo	23	91

Source ClinicalTrials.gov

Papers4

The papers the trial lists on ClinicalTrials.gov.

PMID	Listed as	Source
28337324	DERIVED	PubMed
31199090	DERIVED	PubMed
33476432	DERIVED	PubMed
33838113	DERIVED	PubMed

Grants0

The grants NIH RePORTER links to the trial, newest funded first: NIH's, and some of AHRQ's, CDC's, FDA's and VA's. Each shows its title, principal investigators, organization and funder in its newest year.

None in this release.

Trial comparisons0

Comparisons of the trial's two groups, calculated by ConductScience from the counts it posted.

None in this release.

Tests0

The ConductCognition tests this trial's registered outcomes name, as ScienceGraph matched them in trial-tests-2026-11-12-0.2.1.

None in this release.

Data dates

The day each source was copied for this release.

ClinicalTrials.gov: 2026-11-12; ClinicalTrials.gov
Results, from AACT: 2026-03-23; AACT
NIH grant links: 2026-11-13; NIH RePORTER

Sources 3

ClinicalTrials.gov's posted results, through CTTI's AACTFreely available. Acknowledgement requested
ClinicalTrials.govNo license stated
NIH RePORTER's clinical studies and project filesPublic domain

Each source's terms

ClinicalTrials.gov's posted results, through CTTI's AACTClinicalTrials.gov data via Aggregate Analysis of ClinicalTrials.gov (AACT), CTTI. CTTI makes its materials freely available and requests acknowledgement. https://aact.ctti-clinicaltrials.org/documentation/299
ClinicalTrials.govnone stated
NIH RePORTER's clinical studies and project filesPublic domain (NIH RePORTER)

ClinicalTrials.gov's data carry an international copyright outside the United States: https://clinicaltrials.gov/about-site/terms-conditions.

For software

Read this trial from software.

The record and each of its lists are JSON, twenty rows a page. No key.

GET https://conductscience.org/api/trials/v1/NCT03036813

GET https://conductscience.org/api/trials/v1/NCT03036813/events?page=2

API reference For AI assistants