for people ages 12 years and up (full criteria)
at Oakland, California and other locations
study started
estimated completion



Open Label Extension Study of GBT440 Clinical Trial Patients with Sickle Cell Disease Who Participated in GBT440 Clinical Trials

Official Title

An Open Label Extension Study of GBT440 Administered Orally to Patients With Sickle Cell Disease Who Have Participated in GBT440 Clinical Trials


This open label extension (OLE), multi-center study will be conducted at approximately 100 clinical sites globally and will be available to eligible participants from study GBT440-031.

The study will enroll participants from GBT440-031 (approximately 435) under any of the following conditions:

  • Participant has completed 72 weeks of treatment regardless of dose selection for GBT440-031
  • Dose selection has occurred for GBT440-031 and participant is on non-selected dose
  • GBT440-031 study interim data analysis and/or study modifications have occurred
  • GBT440-031 study has completed

The objective of this open-label extension (OLE) study is to assess the effect of long-term treatment with GBT440 in participants who have completed treatment in study GBT440-031, on the following parameters:

  1. Safety based upon AEs, clinical laboratory tests, physical examinations (PE) and other clinical measures.
  2. Frequency of sickle cell disease (SCD)-related complications.
  3. Hemolytic anemia as measured by hematological laboratory parameters (e.g. hemoglobin, reticulocytes and unconjugated bilirubin).

All participants will receive daily GBT440 treatment.

Participants may receive study drug as long they continue to receive clinical benefit which outweighs risk as determined by the Investigator and/or until the participant has access to GBT440 from an alternative source (i.e., commercialization or through a managed access program).


Sickle Cell Disease Open Label Extension Anemia, Sickle Cell Voxelotor GBT440


You can join if…

Open to people ages 12 years and up

  • 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 GBT440.

  • 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 CAN'T join 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.


  • UCSF Benioff Children's Hospital Oakland
    Oakland California 94609 United States
  • Lynn Health Science Institute
    Oklahoma City Oklahoma 73112 United States


in progress, not accepting new patients
Start Date
Completion Date
Global Blood Therapeutics
Phase 3
Study Type
Last Updated