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

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

Detailed Description
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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

Official Title
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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

Conditions
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Sickle Cell Disease

Intervention / Treatment
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* Drug: open-label GBT021601


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Male or female age 6 months or older with SCD who participated and received study drug or placebo in the previous GBT-Sponsored GBT021601 clinical study and remained on the previous study within 30 calendar days of the Day 1 visit for Study GBT021601-022. 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 GBT021601. Female participants of childbearing potential are required to have a negative urine pregnancy test prior to dosing on Day 1. Note: Female participants who become of childbearing potential during the study must be willing to have negative urine pregnancy tests to remain in the study. If sexually active, female participants 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 120 days after the last dose of study drug. 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 GBT021601 clinical study. Current or recent use of voxelotor. Recent use is defined as within 10 days prior to Day 1.

Ages Eligible for Study
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Minimum Age: 6 Months
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Treatment<br>open-label GBT021601 | Drug: open-label GBT021601<br>* open-label GBT021601<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To evaluate the incidence of SCD treatment-emergent adverse events with the daily dosing of GBT021601 in participants with sickle cell disease | Incidence of treatment-emergent adverse events. | Outcome measures will be evaluated from time of enrollment every 12 weeks through end of treatment up to 4 years | 
| To evaluate the effects of long-term use of GBT021601 on hemolytic anemia. | Change from baseline in hematological laboratory parameters. | Outcome measures will be evaluated from time of enrollment every 12 weeks through end of treatment up to 4 years | 
| To evaluate the long-term effects of GBT021601 treatment on inflammation | Change from baseline in adhesion of whole blood to microfluidic channels. | Outcome measures will be evaluated from time of enrollment every 12 weeks through end of treatment up to 4 years | 
| To evaluate the long-term effects of GBT021601 treatment on quality of life (QOL) assessments | Change from baseline in QOL assessments including Patient Global Impression of Change (PGI-C). | Outcome measures will be evaluated from time of enrollment every 12 weeks through end of treatment up to 4 years | 
| To evaluate the change from baseline in hemoglobin | Change in hemoglobin of daily dosing of GBT021601 in participants with SCD | Outcome measures will be evaluated from time of enrollment every 12 weeks through end of treatment up to 4 years | 
| To evaluate the change from baseline in reticulocytes | Change in reticulocytes from baseline of daily dosing of GBT021601 in participants with SCD | Outcome measures will be evaluated from time of enrollment every 12 weeks through end of treatment up to 4 years | 
| To evaluate the long-term effects of GBT021601 treatment on inflammation | Change from baseline in adhesion of white blood cells to microfluidic channels. | Outcome measures will be evaluated from time of enrollment every 12 weeks through end of treatment up to 4 years | 
| To evaluate the long-term effects of GBT021601 treatment on quality of life (QOL) | Change from baseline in QOL assessments including Clinical Global Impression of Change (CGI-C). | Outcome measures will be evaluated from time of enrollment every 12 weeks through end of treatment up to 4 years | 
| To evaluate the long-term effects of GBT021601 treatment on quality of life (QOL) | Change from baseline in QOL assessments including Patient Global Impression of Severity (PGI-S). | Outcome measures will be evaluated from time of enrollment every 12 weeks through end of treatment up to 4 years | 
| To evaluate the long-term effects of GBT021601 treatment on quality of life (QOL) | Change from baseline in QOL assessments including Clinical Global Impression of Severity (CGI-S). | Outcome measures will be evaluated from time of enrollment every 12 weeks through end of treatment up to 4 years | 
| To evaluate change from baseline in lactate dehydrogenase | Changes in lactate dehydrogenase from baseline of daily dosing of GBT021601 in participants with SCD | Outcome measures will be evaluated from time of enrollment every 12 weeks through end of treatment up to 4 years | 
| To evaluate change from baseline in unconjugated bilirubin | Changes in unconjugated bilirubin from baseline of daily dosing of GBT021601 in participants with SCD | Outcome measures will be evaluated from time of enrollment every 12 weeks through end of treatment up to 4 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To evaluate the pharmacokinetic parameters of long-term exposure to GBT021601 | Trough and 1-to 2-hour post dose blood and plasma concentrations of GBT021601. | Outcome measures will be evaluated from time of enrollment every 12 weeks through end of treatment up to 4 years |