Study to Assess the Effect of Long-term Treatment With Voxelotor in Participants Who Have Completed Treatment in Study GBT440-031

NCT03573882 | Terminated Phase 3 Results FDA Drug

• 2 other identifiers: GBT440-034C5341022
• Study Type: interventional
• Target: 179
• Locations: 11 countries
• Sites: 60

Brief Summary

Open Label Extension Study of Voxelotor Clinical Trial Participants with Sickle Cell Disease Who Participated in Voxelotor Clinical Trials

Conditions

Sickle Cell Disease

Keywords

Open Label Extension

Outcome Measures

Primary Outcomes (6)

• Number of Participants With Sickle Cell Disease (SCD)-Related Treatment Emergent Adverse Events (TEAEs)

  An AE was defined as any untoward medical occurrence associated with the use of a drug in humans, whether or not considered drug related. TEAEs were defined as AEs with onset on or after the date of informed consent until 28 days after last dose of study drug. SCD-related TEAEs included preferred terms (PTs) of sickle cell anaemia with crisis, acute chest syndrome (ACS), pneumonia, priapism, and osteonecrosis. The number of participants with any SCD-related TEAEs was reported in this outcome measure.

  From date of informed consent up to 28 days after last dose of study drug (maximum up to 300.7 weeks)

• Number of Participants With Non- SCD-Related TEAEs

  An AE was defined as any untoward medical occurrence associated with the use of a drug in humans, whether or not considered drug related. TEAEs were defined as AEs with onset on or after the date of informed consent until 28 days after last dose of study drug. Non-SCD-related TEAEs included all the PTs of TEAEs other than SCD- related TEAEs. The number of participants with any non-SCD-related TEAEs was reported in this outcome measure.

  From date of informed consent up to 28 days after last dose of study drug (maximum up to 300.7 weeks)

• Number of Participants With SCD-Related Treatment Emergent Serious Adverse Events (TESAEs)

  An SAE is an AE at any dose, in view of investigator resulted in any of following outcomes: death; life-threatening AE; inpatient hospitalization/prolongation of existing hospitalization; persistent/significant incapacity or disability; a congenital anomaly/birth defect and important medical events (IME) that may not result in death, be immediately life threatening; or require hospitalization may be considered serious when based upon medical judgement, they may jeopardize study participant and may require medical or surgical intervention to prevent one of outcomes listed in definition. TESAEs were defined as SAEs with onset on or after the date of informed consent until 28 days after last dose of study drug. Number of participants with SCD-Related TESAEs was reported in this outcome measure.

  From date of informed consent up to 28 days after last dose of study drug (maximum up to 300.7 weeks)

• Number of Participants With Non-SCD-Related TESAEs

  An SAE is an AE at any dose, in view of investigator resulted in any of following outcomes: death; life-threatening AE; inpatient hospitalization/prolongation of existing hospitalization; persistent/significant incapacity or disability; a congenital anomaly/birth defect and IME that may not result in death, be immediately life threatening; or require hospitalization may be considered serious when based upon medical judgement, they may jeopardize study participant and may require medical or surgical intervention to prevent one of outcomes listed in definition. TESAEs were defined as SAEs with onset on or after the date of informed consent until 28 days after last dose of study drug. Number of participants with non-SCD related TESAEs was reported in this outcome measure.

  From date of informed consent up to 28 days after last dose of study drug (maximum up to 300.7 weeks)

• Annualized Incidence Rate (Events Per Person Years) of SCD-Related Complications

  Annualized incidence rate was defined as total number of events (i.e. complications observed for all participants) divided by total person years. Total person-years= sum of participant summary period in years where summary period=date of informed consent until the earlier of 28 days after last dose of study drug or end of study date. SCD related complications included acute chest syndrome, cerebrovascular accident, hepatic sequestration, ocular icterus, osteonecrosis, pneumonia, priapism, pulmonary hypertension, retinopathy, sickle cell anaemia with crisis, skin ulcer and splenic sequestration. The 95% CI was based on exact Poisson confidence limits. Incidence rate of all SCD related complications is reported in this outcome measure.

  From date of informed consent up to earlier of 28 days after last dose of study drug or end of study date (maximum up to 300.7 weeks)

• Annualized Incidence Rate (VOC Events Per Person Years) of On-Treatment Vaso-occlusive Crisis (VOCs)

  Annualized incidence rate was defined as total number of VOC events divided by total person years. Total person-years= sum of participant summary period in years where summary period=date of informed consent to last dose of study drug. VOC during the treatment period was defined as composite of acute painful crisis or acute chest syndrome (ACS) and included the following: moderate to severe pain lasting at least 2 hours; no explanation other than VOC; required oral or parenteral opioids, ketorolac, or other analgesics prescribed or directed by a healthcare professional. The 95% CI was based on exact Poisson confidence limits.

  From date of informed consent to last dose of study drug (maximum up to 296.7 weeks)

Secondary Outcomes (4)

• Change From Baseline in Hemoglobin Level at Week 48

  Baseline, Week 48

• Percent Change From Baseline in Reticulocytes Percentage at Week 48

  Baseline, Week 48

• Percent Change From Baseline in Absolute Reticulocytes at Week 48

  Baseline, Week 48

• Percent Change From Baseline in Indirect Bilirubin at Week 48

  Baseline, Week 48

Study Arms (1)

Voxelotor

OTHER

Participants will receive voxelotor (GBT440) at the highest dose (either 900 mg or 1500 mg) deemed safe by the Data Safety Monitoring Board (DSMB).

Drug: Voxelotor

Interventions

Voxelotor DRUG

300mg or 500mg Tablet, Oral, With or Without Food

Also known as: GBT440

Voxelotor

Eligibility Criteria

• Age: 12 Years - 65 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)

You may qualify if:

• Male or female study participants with SCD who participated and received study treatment in Study GBT440-031.
• Note: Participants in GBT440-031 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.
• Females of child-bearing potential are required to have a negative urine pregnancy test prior to dosing on Day 1.
• Female participants of child-bearing potential must use highly effective methods of contraception to 30 days after the last dose of study drug. Male participants must use barrier methods of contraception to 30 days after the last dose of study drug.
• Participant has provided written informed consent or assent (the ICF must be reviewed and signed by each participant; in the case of pediatric participants, both the consent of the participant's legal representative or legal guardian, and the participant's assent must be obtained).

You may not qualify if:

• Female who is breast-feeding or pregnant.
• Participant withdrew consent from Study GBT440-031.
• Participant was lost to follow-up from Study GBT440-031.
• Participant requiring chronic dialysis.
• Any medical, psychological, safety, or behavioral conditions, which, in the opinion of the Investigator, may confound safety interpretation, interfere with compliance, or preclude informed consent.

Sponsors & Collaborators

• Pfizer: lead

Study Sites (60)

Arkansas Primary Care Clinic, PA

Little Rock, Arkansas, 72204, United States

Location

UCSF Benioff Children's Hospital Oakland

Oakland, California, 94609, United States

Location

Jackson Memorial Hospital (Investigational Drug Services)

Miami, Florida, 33136, United States

Location

Jackson Memorial Hospital

Miami, Florida, 33136, United States

Location

University of Miami Hospital & Clinics/SCCC, Research Pharmacy (Investigational Drug Services)

Miami, Florida, 33136, United States

Location

University of Miami

Miami, Florida, 33136, United States

Location

Children's Healthcare of Atlanta - Scottish Rite

Atlanta, Georgia, 30342, United States

Location

University of Illinois at Chicago Clinical Research Center

Chicago, Illinois, 60612, United States

Location

University of Illinois Hospital and Health Science System

Chicago, Illinois, 60612, United States

Location

Indiana Hemophilia and Thrombosis Center

Indianapolis, Indiana, 46260, United States

Location

St. Jude Affiliate Clinic Baton Rouge

Baton Rouge, Louisiana, 70808, United States

Location

Our Lady of the Lake Physician Group-Medical Oncology

Baton Rouge, Louisiana, 70809, United States

Location

University Medical Center New Orleans

New Orleans, Louisiana, 70112, United States

Location

Johns Hopkins University/Sickle Cell Infusion Center

Baltimore, Maryland, 21287, United States

Location

Brigham and Women's Hospital

Boston, Massachusetts, 02115, United States

Location

Brigham and Women's Hospital Research Pharmacy

Boston, Massachusetts, 02215, United States

Location

Dana Farber Cancer Institute

Boston, Massachusetts, 02215, United States

Location

Children's Hospital of Michigan

Detroit, Michigan, 48201, United States

Location

Newark Beth Israel Medical Center

Newark, New Jersey, 07112, United States

Location

Columbia University Medical Center - Herbert Irving Pavilion

New York, New York, 10032, United States

Location

Montefiore - Einstein Center for Cancer Care

The Bronx, New York, 10461, United States

Location

UNC Hospitals

Chapel Hill, North Carolina, 27514, United States

Location

Clinical and Translational Research Center (CTRC)

Chapel Hill, North Carolina, 27599, United States

Location

Duke University Medical Center

Durham, North Carolina, 27710, United States

Location

Investigational Drug Service, Duke University Hospital

Durham, North Carolina, 27710, United States

Location

Lynn Health Science Institute

Oklahoma City, Oklahoma, 73112, United States

Location

Thomas Jefferson University

Philadelphia, Pennsylvania, 19107, United States

Location

University of Pittsburgh Medical Center (UPMC)

Pittsburgh, Pennsylvania, 15232, United States

Location

Medical University of South Carolina - Comprehensive Sickle Cell Clinic

Charleston, South Carolina, 29425, United States

Location

Medical University of South Carolina: Investigational Drug Services Pharmacy

Charleston, South Carolina, 29425, United States

Location

Methodist Comprehensive Sickle Cell Clinic

Memphis, Tennessee, 38104, United States

Location

Texas Children's Hospital - Investigational Pharmacy

Houston, Texas, 77030, United States

Location

Texas Children's Hospital

Houston, Texas, 77030, United States

Location

Clinical Research Services Unit- Virginia Commonwealth University

Richmond, Virginia, 23298, United States

Location

Toronto General Hospital-University Health Network

Toronto, Ontario, M5G 2C4, Canada

Location

Alexandria Clinical Research Center, Faculty of Medicine, Alexandria University

Alexandria, Egypt

Location

Alexandria Clinical Research Center, Faculty of Medicine

Alexandria, Egypt

Location

Zagazig University Hospital

Alsharkia, Egypt

Location

Abu El Rich Hospital,Cairo University Hospital

Cairo, 11541, Egypt

Location

Ain Shams University Hospital

Cairo, Egypt

Location

The Egyptian Thalassemia Association ( E.T.A)

Cairo, Egypt

Location

Hôpital Européen Georges Pompidou - Medecine Interne

Paris, 75015, France

Location

Azienda Ospedaliera di Padova

Padua, Padova Veneto, 35128, Italy

Location

Centres for Disease Control and Prevention

Siaya, Kisumu County, Kenya

Location

KEMRI/CRDR - Kenya Medical Research Insititute - Center for respiratory Disease Research

Nairobi, 00101, Kenya

Location

Gertrude's Children's Hospital

Nairobi, Kenya

Location

American University of Beirut

Beirut, Lebanon

Location

Nini Hospital

Tripoli, Lebanon

Location

Academic Medical Center(AMC)

Amsterdam, 1105 AZ, Netherlands

Location

ErasmusMC

Rotterdam, 3015 CN, Netherlands

Location

Sultan Qaboos University Hospital

Muscat, 123, Oman

Location

Adana Acibadem Hospital

Adana, 01130, Turkey (Türkiye)

Location

Erciyes Universitesi Tip Fakultesi

Kayseri, 38039, Turkey (Türkiye)

Location

Mersin Universitesi Tip Fakultesi Saglik Arastirma ve Uygulama Hastanesi

Mersin, 33343, Turkey (Türkiye)

Location

Barts Health NHS Trust

London, Greater London, E1 1BB, United Kingdom

Location

Homerton University Hospital NHS Foundation Trust

London, Greater London, E9 6SR, United Kingdom

Location

Guys and St. Thomas Hospital NHS Foundation Trust

Great Maze Pond, London, SE1 9RT, United Kingdom

Location

King's College Hospital

London, SE5 9RS, United Kingdom

Location

Imperial College Healthcare NHS Trust, Hammersmith Hospital

London, W12 0HS, United Kingdom

Location

McMillan Cancer Centre

London, WC1E 6AG, 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

Study Record Dates

• First Submitted: May 15, 2018
• First Posted: June 29, 2018
• Study Start: June 6, 2018
• Primary Completion: November 12, 2024
• Study Completion: November 12, 2024
• Last Updated: November 18, 2025
• Results First Posted: November 18, 2025

Record last verified: 2025-11

Data Sharing

• IPD Sharing: Will share

Locations

TU (3); FR (1); IT (1); EG (6); LE (2); NL (2); US (34); KE (3); OM (1); CA (1); GB (6)