Dose Escalation Study to Evaluate the Safety, Tolerability, PK and PD of Voxelotor in Patients With SCD
![]() |
The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Know the risks and potential benefits of clinical studies and talk to your health care provider before participating. Read our disclaimer for details. |
ClinicalTrials.gov Identifier: NCT04247594 |
Recruitment Status :
Recruiting
First Posted : January 30, 2020
Last Update Posted : March 16, 2020
|
- Study Details
- Tabular View
- No Results Posted
- Disclaimer
- How to Read a Study Record
Condition or disease | Intervention/treatment | Phase |
---|---|---|
Sickle Cell Disease | Drug: Voxelotor | Phase 2 |
Study Type : | Interventional (Clinical Trial) |
Estimated Enrollment : | 45 participants |
Allocation: | Non-Randomized |
Intervention Model: | Sequential Assignment |
Masking: | None (Open Label) |
Primary Purpose: | Treatment |
Official Title: | A Phase 2, Open Label, Multiple Dose Escalation Study to Evaluate the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of Voxelotor in Patients With Sickle Cell Disease |
Actual Study Start Date : | January 9, 2020 |
Estimated Primary Completion Date : | June 2021 |
Estimated Study Completion Date : | December 2021 |

Arm | Intervention/treatment |
---|---|
Experimental: Cohort A open label
Participants will receive progressively higher doses of voxelotor administration starting from 1500 mg
|
Drug: Voxelotor
synthetic small molecule supplied as 500 mg tablets |
Experimental: Cohort B open label
Participants will receive doses higher than 1500 mg administered without up-titration
|
Drug: Voxelotor
synthetic small molecule supplied as 500 mg tablets |
- Treatment-emergent AEs [ Time Frame: approximately 200 days ]Treatment emergent AEs including SAEs
- Change in Hb and clinical measures of hemolysis (unconjugated bilirubin, % reticulocyte, absolute reticulocyte, and lactate dehydrogenase [LDH]) from Baseline [ Time Frame: approximately 200 days ]Change in Hb
- Proportion of participants with an Hb increase > 1 g/dL compared to Baseline [ Time Frame: approximately 200 days ]participants with an Hb increase > 1 g/dL compared to Baseline

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.
Ages Eligible for Study: | 18 Years to 60 Years (Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
Inclusion Criteria:
- Male or female with sickle cell disease
- Documentation of SCD genotype HbSS or HbSB0
- Age 18 to < 60 years, inclusive
- Participants, who if female and of child bearing potential, agree to use highly effective methods of contraception or practicing abstinence from study start to 30 days after the last dose of study drug, and who if male, agree to use barrier methods of contraception or practice abstinence from study start to 30 days after the last dose of study drug
- Participant has provided documented informed consent
Exclusion Criteria:
- More than 10 vaso-occlusive crises (VOCs) within 12 months of screening that required a hospital, emergency room, or clinic visit
- Female participant who is breast feeding or pregnant
- Hospitalized for sickle cell crisis or other vaso-occlusive event prior to 30 days of dosing (ie, a vaso-occlusive event cannot be within 30 days prior to dosing)
- Participants with known active hepatitis A, B, or C or who are known to be human immunodeficiency virus (HIV) positive
- Severe renal dysfunction or on chronic dialysis
- History of malignancy within the past 2 years prior to treatment Day 1 requiring chemotherapy and/or radiation (with the exception of local therapy for non-melanoma skin malignancy)
- History of unstable or deteriorating cardiac or pulmonary disease within 6 months prior to consent including but not limited to the following:
- Participated in another clinical trial of an investigational agent or medical device within 30 days or 5 half-lives of date of informed consent, whichever is longer, or is currently participating in another trial of an investigational agent or medical device
- Inadequate venous access as determined by the Investigator/site staff
- Ongoing or recent (within 2 years) substance abuse
- Inability to undergo magnetic resonance imaging (MRI) or cardiopulmonary exercise test (CPET) assessments (Cohort B only)
- Known allergy to voxelotor

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT04247594
Contact: Will Tappe, MD | (650) 825-4678 | wtappe@gbt.com | |
Contact: Theresa Thuener | +1 650 741 7710 | tthuener@gbt.com |
United Kingdom | |
Guy's and St Thomas' NHS Foundation Trust | Recruiting |
London, United Kingdom | |
Contact: Yemi Adelaja +44 (0)779 907 6144 yemi.adelaja@nhs.net | |
Principal Investigator: Henry Fok, MD | |
Guy's Hospital | Recruiting |
London, United Kingdom | |
Contact: Thompson Olaoni +44 (0)207 188 7188 ext 56496 thompson.olaoni@gstt.nhs.uk | |
Principal Investigator: Jo Howard, Professor | |
Hammersmith Hospital | Recruiting |
London, United Kingdom | |
Contact: Zainab Alashe +44 (0)203 313 8553 zainab.alashe@nhs.net | |
Principal Investigator: Mark Layton, Professor | |
Homerton University | Recruiting |
London, United Kingdom | |
Contact: Jessica Vize +44 (0)208 510 5785 jessica.vize@nhs.net | |
Principal Investigator: Dimitris Tsitsikas, MD | |
King's College Hospital | Recruiting |
London, United Kingdom | |
Contact: Karen Torre +44 (0) 20 3299 5501 karen.torre@nhs.net | |
Contact: Jen Lewis jen.lewis2@nhs.net | |
Principal Investigator: Moji Awogbade, MD | |
Royal London Hospital, Barts Health NHS Trust | Recruiting |
London, United Kingdom | |
Contact: Tasnima Ferdousi +44 (0)203 246 0261 tasnima.ferdousi@nhs.uk | |
Principal Investigator: Paul Telfer, DM |
Responsible Party: | Global Blood Therapeutics |
ClinicalTrials.gov Identifier: | NCT04247594 |
Other Study ID Numbers: |
GBT440-029 |
First Posted: | January 30, 2020 Key Record Dates |
Last Update Posted: | March 16, 2020 |
Last Verified: | March 2020 |
Studies a U.S. FDA-regulated Drug Product: | Yes |
Studies a U.S. FDA-regulated Device Product: | No |
Sickle Cell Disease, SCD |
Anemia, Sickle Cell Anemia, Hemolytic, Congenital Anemia, Hemolytic Anemia |
Hematologic Diseases Hemoglobinopathies Genetic Diseases, Inborn |