GBT021601-022: A Study of GBT021601 in Participants With Sickle Cell Disease (SCD)

An Open-label Extension Study to Evaluate the Long-term Safety of GBT021601 Administered to Participants With Sickle Cell Disease Who Have Participated in a GBT021601 Clinical Trial

An Open-label Extension Study of GBT021601 in Participants with Sickle Cell Disease

An Open-label Extension Study to Evaluate the Long-term Safety and Efficacy of GBT021601 Administered to Participants with Sickle Cell Disease Who Have Participated in a GBT021601 Clinical Trial

Inclusion Criteria:

1. Male or female aged 6 months or older with SCD who participated and received study drug or placebo in a previous osivelotor clinical study and completed the end of treatment visit.

   Note: Participants who discontinued study drug in the originating study due to an TEAE, but who remained on study, may be eligible for treatment in this study provided the TEAE does not pose a risk for treatment with osivelotor.

2. Females of childbearing potential are required to have a negative urine pregnancy test prior to dosing on Day 1.

   Note: Females who become of childbearing potential during the study must be willing to have negative urine pregnancy tests to remain in the study.

3. If sexually active, females of childbearing potential must consistently use highly effective methods of contraception consistently throughout the study and for at least 120 days after the last dose of study drug. If sexually active, male participants must use barrier methods of contraception until 84 days after the last dose of study drug. Male participants are eligible to participate if they agree to the following requirements during the study intervention period and for 84 days after the last dose of study intervention:

   • Refrain from donating sperm PLUS either
   • Be abstinent from heterosexual intercourse as their preferred and usual lifestyle OR
   • Must agree to use a male condom when engaging in any activity that allows for passage of ejaculate to another person

4. Participant has provided written informed consent/assent. For underage participants, both the consent of the participant's legal representative or legal guardian and the participant's assent (where applicable) must be obtained based on local requirements.

Exclusion Criteria:

• Participant withdrew consent or was noncompliant from the originating osivelotor clinical study
• Current or recent use of voxelotor. Recent use is defined as within 10 days prior to Day 1
• Current or recent use of crizanlizumab. Recent use is defined as within 90 days prior to Day 1
• Participant has any medical, psychological, safety, or behavioral conditions that, in the opinion of the Investigator, may confound safety interpretation, interfere with compliance, or preclude informed consent
• Has received an investigational drug (including investigational vaccines) within 5 times the elimination half-life (if known) or within 30 days (if the elimination half-life- is unknown) prior to study drug administration or is concurrently enrolled in any research judged not to be scientifically or medically compatible with this study