Trial · NCT04247594

Dose Escalation Study to Evaluate the Safety, Tolerability, PK and PD of Voxelotor in Patients With SCD

NCT04247594, Phase 2, Terminated, Pfizer; results first posted 2023-11-21

3 sourcestrials-2026-11-12-0.5.0

Cite this record

ConductScience Library. Dose Escalation Study to Evaluate the Safety, Tolerability, PK and PD of Voxelotor in Patients With SCD. Trials, record NCT04247594. Release trials-2026-11-12-0.5.0, 12 Nov 2026. https://conductscience.org/library/trials/NCT04247594

On this page

Trial

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

Title: Dose Escalation Study to Evaluate the Safety, Tolerability, PK and PD of Voxelotor in Patients With SCD
NCT number: NCT04247594
Status: Terminated
Phases: Phase 2
Enrollment: 6 participants, actual
Lead sponsor: Pfizer
Conditions: Sickle Cell Disease
Interventions: Voxelotor
First posted: 2020-01-30
Last updated: 2023-11-21
Results first posted: 2023-11-21

Source ClinicalTrials.gov

Registered outcomes4

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

List	Outcome	Time frame	Description
Primary	Treatment-emergent Adverse Events (AEs)	approximately 300 days	Treatment emergent AEs including SAEs
Secondary	Number of Participants With Clinically Significant Abnormalities in Hb, Unconjugated Bilirubin, % Reticulocyte, Absolute Reticulocyte, and Lactate Dehydrogenase [LDH]	approximately 200 days
Secondary	Number of Participants With an Hb Increase > 1 g/dL Compared to Baseline	approximately 200 days	Participants with an Hb increase \> 1 g/dL compared to Baseline.
Secondary	Incidence Rate of VOCs	approximately 200 days	Incidence rate of vaso-occlusive crisis

Source ClinicalTrials.gov

Outcomes4

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

Type	Outcome	Time frame	Population	Units	Measured as
PRIMARY	Treatment-emergent Adverse Events (AEs)	approximately 300 days	Subjects treated with at least one dose of voxelotor	Participants	COUNT_OF_PARTICIPANTS
SECONDARY	Number of Participants With Clinically Significant Abnormalities in Hb, Unconjugated Bilirubin, % Reticulocyte, Absolute Reticulocyte, and Lactate Dehydrogenase [LDH]	approximately 200 days	Subjects treated with at least one dose of Voxelotor	Participants	COUNT_OF_PARTICIPANTS
SECONDARY	Number of Participants With an Hb Increase > 1 g/dL Compared to Baseline	approximately 200 days	Subjects treated with at least one dose of Voxelotor	Participants	COUNT_OF_PARTICIPANTS
SECONDARY	Incidence Rate of VOCs	approximately 200 days	Subjects treated with at least one dose of Voxelotor	Participants	COUNT_OF_PARTICIPANTS

Source ClinicalTrials.gov

Results by group14

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

Outcome	Group	Category	Value	Units
Treatment-emergent Adverse Events (AEs)	Voxelotor 1500 mg	Sickle cell disease (SCD) related TEAE	5	Participants
Treatment-emergent Adverse Events (AEs)	Voxelotor 2000 mg	Sickle cell disease (SCD) related TEAE	1	Participants
Treatment-emergent Adverse Events (AEs)	Voxelotor 2500 mg	Sickle cell disease (SCD) related TEAE	1	Participants
Treatment-emergent Adverse Events (AEs)	Voxelotor 3000 mg	Sickle cell disease (SCD) related TEAE	0	Participants
Treatment-emergent Adverse Events (AEs)	Voxelotor 1500 mg	Non-SCD related TEAE	6	Participants
Treatment-emergent Adverse Events (AEs)	Voxelotor 2000 mg	Non-SCD related TEAE	4	Participants
Treatment-emergent Adverse Events (AEs)	Voxelotor 2500 mg	Non-SCD related TEAE	2	Participants
Treatment-emergent Adverse Events (AEs)	Voxelotor 3000 mg	Non-SCD related TEAE	1	Participants
Number of Participants With Clinically Significant Abnormalities in Hb, Unconjugated Bilirubin, % Reticulocyte, Absolute Reticulocyte, and Lactate Dehydrogenase [LDH]	Voxelotor 1500 mg		0	Participants
Number of Participants With Clinically Significant Abnormalities in Hb, Unconjugated Bilirubin, % Reticulocyte, Absolute Reticulocyte, and Lactate Dehydrogenase [LDH]	Voxelotor 2000 mg		0	Participants

1 to 10 of 14Source ClinicalTrials.gov

See all 14 results by group

Participant flow3

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

Period	Milestone	Group	Participants
Overall Study	STARTED	Open Label	6
Overall Study	COMPLETED	Open Label	2
Overall Study	NOT COMPLETED	Open Label	4

Source ClinicalTrials.gov

Adverse events136

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
other	Alanine aminotransferase increased	Investigations	Period 1	1	6
other	Alanine aminotransferase increased	Investigations	Period 2	0	4
other	Alanine aminotransferase increased	Investigations	Period 3	2	3
other	Alanine aminotransferase increased	Investigations	Period 4	0	1
other	Headache	Nervous system disorders	Period 1	1	6
other	Headache	Nervous system disorders	Period 2	2	4
other	Headache	Nervous system disorders	Period 3	1	3
other	Headache	Nervous system disorders	Period 4	0	1
other	Fatigue	General disorders	Period 1	2	6
other	Fatigue	General disorders	Period 2	0	4

1 to 10 of 136Source ClinicalTrials.gov

See all 136 adverse events

Adverse event totals12

The totals the trial posted for each group.

Total	Group	Affected	At risk
Total, all-cause mortality	Period 1	0	6
Total, all-cause mortality	Period 2	0	4
Total, all-cause mortality	Period 3	0	3
Total, all-cause mortality	Period 4	0	1
Total, other adverse events	Period 1	6	6
Total, other adverse events	Period 2	4	4
Total, other adverse events	Period 3	2	3
Total, other adverse events	Period 4	1	1
Total, serious adverse events	Period 1	4	6
Total, serious adverse events	Period 2	0	4

1 to 10 of 12Source ClinicalTrials.gov

See all 12 adverse event totals

Papers0

The papers the trial lists on ClinicalTrials.gov.

None in this release.

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/NCT04247594

GET https://conductscience.org/api/trials/v1/NCT04247594/events?page=2

API reference For AI assistants