Open-Label Extension of Voxelotor

NCT04188509 | Terminated Phase 3 Results FDA Drug

• 3 other identifiers: GBT440-0382019-003144-76C5341023
• Study Type: interventional
• Target: 162
• Locations: 5 countries
• Sites: 20

Brief Summary

Open-label extension study of voxelotor for participants with Sickle Cell Disease who have participated in voxelotor clinical trials.

Conditions

Sickle Cell Disease

Outcome Measures

Primary Outcomes (3)

• Number of Participants With Treatment Emergent Adverse Events (AEs)

  An AE was defined as any untoward medical occurrence associated with the use of a drug in humans, whether or not considered to be drug related. A treatment emergent AE was defined as an AE with an onset date on or after the date of informed consent until 28 days after discontinuation of drug. AEs included both serious AEs (SAEs) and all non-SAEs. An SAE was an AE or suspected adverse reaction that, at any dose, in the view of the either the investigator or sponsor, resulted in any of the following outcomes: death, was life-threatening, resulted in persistent disability/incapacity; constituted a congenital anomaly/birth defect; was important medical event; required inpatient hospitalization or prolongation of existing hospitalization.

  From date of informed consent until 28 days after last dose of study drug (maximum up to 4.31 years)

• Number of Participants With SAEs

  An AE was defined as any untoward medical occurrence associated with the use of a drug in humans, whether or not considered to be drug related. An SAE was an AE or suspected adverse reaction that, at any dose, in the view of the either the investigator or sponsor, resulted in any of the following outcomes: death, was life-threatening, resulted in persistent disability/incapacity; constituted a congenital anomaly/birth defect; was important medical event; required inpatient hospitalization or prolongation of existing hospitalization.

  From date of informed consent until 28 days after last dose of study drug (maximum up to 4.31 years)

• Number of Participants With Sickle Cell Disease (SCD) Related TEAEs and SAEs

  SCD-related AEs were common complications associated with the study participant's SCD and were not considered to be related to voxelotor unless judged by the investigator to have worsened in severity and/or frequency or changed in nature during the study. SCD-related complications included the following: sickle cell anemia with crisis, acute chest syndrome (ACS), pneumonia, priapism, and osteonecrosis. A treatment emergent AE was defined as an AE with an onset date on or after the date of informed consent until 28 days after discontinuation of drug. An SAE was an AE or suspected adverse reaction that, at any dose, in the view of either the investigator or sponsor, resulted in any of the following outcomes: death, was life-threatening, resulted in persistent disability/incapacity; constituted a congenital anomaly/birth defect; was important medical event; required inpatient hospitalization or prolongation of existing hospitalization.

  From date of informed consent until 28 days after last dose of study drug (maximum up to 4.31 years)

Study Arms (1)

Voxelotor

EXPERIMENTAL

All participants will receive voxelotor once daily (QD), administered orally as tablets, dispersible tablets, or a stick pack formulation (powder blend formulation packaged as stick packs). Participants aged ≥ 12 years and/or ≥ 40 kgs will receive a voxelotor dose of 1500 mg QD. Participants aged \< 12 years and \< 40 kgs will receive weight based dosing of voxelotor. The participant's weight at study entry will be used to determine the starting voxelotor dose in this study. Participants may receive study drug as long they continue to receive clinical benefit that outweighs risk as determined by the investigator and/or until the participant has access to voxelotor from an alternative source.

Drug: Voxelotor

Interventions

Voxelotor DRUG

All participants will receive voxelotor once daily (QD), administered orally as tablets, dispersible tablets, or a powder for oral suspension formulation (powder formulation packaged as stick packs).

Also known as: GBT440

Voxelotor

Eligibility Criteria

• Age: 6 Months+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)

You may qualify if:

• Male or female participant with SCD, who participated and received study drug in a GBT-sponsored voxelotor clinical study.
• Note: Participants who discontinued study drug due to an AE, but who remained on study, may be eligible for treatment in this study provided the AE does not pose a risk for treatment with voxelotor.
• Note: Participants who discontinued Study GBT440-032 as the result of an abnormal transcranial Doppler (TCD) flow velocity assessment (≥ 200 cm/sec) are eligible for treatment in this study.
• \- Participant has provided written consent/assent (for pediatric participants, both the consent of the participant's legal representative or legal guardian and the participant's assent \[where applicable\] must be obtained).

You may not qualify if:

• Female participant who is breastfeeding or pregnant
• Participant withdrew consent from a GBT-sponsored voxelotor clinical study
• Known hypersensitivity to voxelotor or any other components of the study drug
• Use of St. John's wort, sensitive cytochrome P450 (CYP) 3A4 substrates with a narrow therapeutic index, or moderate or strong CYP3A4 inducers within 30 days of Day 1

Sponsors & Collaborators

• Pfizer: lead

Study Sites (20)

Children's National Medical Center

Washington D.C., District of Columbia, 20010, United States

Location

Children's Healthcare of Atlanta Scottish Rite

Atlanta, Georgia, 30342, United States

Location

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

Chicago, Illinois, 60611, United States

Location

Children's Mercy Hospital

Kansas City, Missouri, 64108, United States

Location

ECU Physicians, Brody Outpatient Clinic

Greenville, North Carolina, 27834, United States

Location

UPMC Children's Hospital of Pittsburgh

Pittsburgh, Pennsylvania, 15224, United States

Location

Zagazig University Hospital

Zagazig, Alsharkia, Egypt

Location

Alexandria University Hospital - Clinical Research Center

Alexandria, 21131, Egypt

Location

Cairo University Hospital, Abu El Rish Hospital

Cairo, 11562, Egypt

Location

Ain Shams University Hospital - Clinical Research Center (MASRI-CRC)

Cairo, Egypt

Location

American University of Beirut - Medical Center

Beirut, Lebanon

Location

Nini Hospital

Tripoli, Lebanon

Location

University of Calabar Teaching Hospital

Calabar, Cross River State, 540281, Nigeria

Location

College of Medicine, University of Ibadan

Ibadan, Oyo State, 200212, Nigeria

Location

Barau Dikko Teaching Hospital/Kaduna State University

Kaduna, 800212, Nigeria

Location

Aminu Kano Teaching Hospital

Kano, 700233, Nigeria

Location

Lagos University Teaching Hospital

Lagos, 100254, Nigeria

Location

University College Hospital NHS Foundation Trust

London, Greater London, NW1 2PG, United Kingdom

Location

Barts Health NHS Trust , The Royal London Hospital

London, E1 1BB, United Kingdom

Location

Guy'S and St Thomas' Nhs Foundation Trust

London, SE1 7EH, United Kingdom

Location

Related Links

• To obtain contact information for a study center near you, click here.

MeSH Terms

Conditions

Anemia, Sickle Cell

Interventions

voxelotor

Condition Hierarchy (Ancestors)

Anemia, Hemolytic, Congenital; Anemia, Hemolytic; Anemia; Hematologic Diseases; Hemic and Lymphatic Diseases; Hemoglobinopathies; Genetic Diseases, Inborn; Congenital, Hereditary, and Neonatal Diseases and Abnormalities

Results Point of Contact

• Title: Pfizer ClinicalTrials.gov Call Center
• Organization: Pfizer Inc.

ClinicalTrials.gov_Inquiries@pfizer.com

1-800-718-1021

Study Officials

• Pfizer CT.gov Call Center

  Pfizer

  STUDY DIRECTOR

Publication Agreements

• PI is Sponsor Employee: No
• Restriction Type: OTHER
• Restrictive Agreement: Yes

Study Design

• Study Type: interventional
• Phase: phase 3
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR
• Expanded Access: Yes

Model Details: Open-Label Extension study available to eligible participants from GBT-sponsored voxelotor clinical studies.

Study Record Dates

• First Submitted: December 3, 2019
• First Posted: December 6, 2019
• Study Start: November 18, 2019
• Primary Completion: November 1, 2024
• Study Completion: November 1, 2024
• Last Updated: November 13, 2025
• Results First Posted: November 13, 2025

Record last verified: 2025-10

Data Sharing

• IPD Sharing: Will share

Locations

US (6); NG (5); GB (3); EG (4); LE (2)