A Study to Evaluate GBT021601-012 Single Dose and Multiple Dose in Participants With Sickle Cell Disease (SCD)

A Phase 1 study testing GBT021601 in people with Sickle Cell Disease, run by Pfizer at 3 sites in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Trial summary

The purpose of this study is to evaluate the safety, tolerability, and pharmacokinetics (PK), and pharmacodynamics (i.e., how the body absorbs, distributes, breaks down, and excretes) of GBT021601, a hemoglobin S (HbS) polymerization inhibitor, in participants with SCD, following single and multiple ascending doses. Read more about this study

Who is it for?: Ages 18 to 60 years
Conditions the study is for: Sickle Cell Disease
What is being tested?: GBT021601
Type of treatment: Pill or oral medicine
Could I receive a placebo?: No, everyone receives an active treatment
How many people: 6 participants
Where: 3 sitesUnited States
Study dates: 21 May 2021to 6 Dec 2022
Phase: Phase 1
Are there results?: Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

Ages 18 to 60 years
All sexes
No healthy volunteers
Adult

Who may be able to join

Male or Female with SCD
Participants with SCD ages 18 to 60 years, inclusive.
Participant has provided documented informed consent.
Patients with stable and close to baseline hemoglobin value
Patients on HU should be on stable dose for at least 90 days prior to signing ICF

Who cannot join

Patients had more than 10 VOC within 12 months of screening
Patients who are pregnant or nursing
Patients who receive RBC transfusion therapy regularly or received an RBC transfusion for any reason within 60 days of signing the ICF
Hospitalized for sickle cell crisis or other vaso-occlusive event within 14 days of signing the ICF or within 24 days prior to Day 1 treatment

Trial locations and contacts

3 sites in 1 country.

United States3 sites

Visionaries Clinical Research LLC
Atlanta, Georgia, 30329
Children's Healthcare of Atlanta AFLAC Center
Atlanta, Georgia, 30342
Advanced Pharma CR, LLC
Miami, Florida, 33147

Other trials in United States

About this study

Official title: An Intrapatient Single Dose and Multiple Ascending Dose Study to Evaluate the Pharmacokinetics, Safety, Tolerability, and Pharmacodynamics of GBT021601, a Hemoglobin S Polymerization Inhibitor, in Participants With Sickle Cell Disease (SCD)

Read the detailed description

This is an open-label intrapatient single dose followed by a multiple dose escalation study in at least six (6) participants with SCD.

Conditions: Sickle Cell Disease
Being tested: GBT021601
Medical subject headings: Anemia, Sickle Cell

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

GBT021601Drug
Tablets and capsules which contain GBT021601 drug substance

Study groups in NCT04983264
Study group	Role	What they receive
Single-dose Period (Part A)	Experimental	Refer to Study Description Receives: Drug: GBT021601
Multiple Ascending-dose Period (Part B and Part C)	Experimental	Refer to Study Description Receives: Drug: GBT021601

What is being measured

The primary outcome is the main question the study is designed to answer.

Number of Participants With Treatment Emergent Adverse Events (TEAEs) and Serious Adverse Events (SAEs)
An adverse event (AE) was any untoward medical occurrence in a study participant administered a product or medical device; the event need not necessarily have a causal relationship with the treatment or usage. A treatment-emergent AE (TEAE) was an AE that occurs or worsens during the on-treatment period defined as the time from the first dose of study drug through minimum of 56 days after last dose of study treatment. A Serious Adverse Event (SAE) was any untoward medical occurrence at any dose that: resulted in death; was life-threatening experience (immediate risk of death); required inpatient hospitalization or prolongation if existing hospitalization; resulted in persistent or significant disability/ incapacity; resulted in congenital anomaly/birth defect; was considered an important medical event. TEAEs and SAEs were reported for both Sickle Cell Disease (SCD) and non-SCD related events, in this outcome measure.
Measured: From first dose of study drug (Day 1) to at least 56 days after last dose of study drug (up to a maximum of 316 days)
Number of Participants With Clinically Significant Physical Examination Findings
Physical examination included were general appearance, head, ears, eyes, nose, throat, neck, skin, cardiovascular system, respiratory system, gastrointestinal system, musculoskeletal system, lymph nodes, and nervous system. Clinically significant physical examination abnormalities were considered as adverse events based on investigator's discretion.
Measured: Baseline (Day 1) up to at least 56 days after last dose of study drug (up to a maximum of 316 days)
Number of Participants With Clinically Significant Change From Baseline in Laboratory Parameters
Laboratory parameters included hematology(hemoglobin,hematocrit,red blood cell count,platelet count,white blood cell count,total neutrophils,eosinophils,monocytes,basophils,lymphocytes);blood chemistry(blood urea,nitrogen, creatinine,glucose,calcium,sodium,potassium,chloride,total bicarbonate,aspartate aminotransferase,alanine aminotransferase,total bilirubin,alkaline phosphatase,uric acid albumin,total protein);urinalysis(decimal logarithm of reciprocal of hydrogen ion activity [pH], glucose, protein, blood,ketones, microscopy[urine tested positive for blood or protein]),urine drug screening:cannabinoids,amphetamines,methamphetamines,opiates,methadone,cocaine,benzodiazepines,phencyclidine,barbiturates,alcohol breath test. Hemoximetry RBC deformability,dense cells test; erythropoietin,follicle stimulating hormone,pregnancy test,Serology panel for HIV 1/2 antibody,Hepatitis A, B and C,SARS CoV-2.Clinical significance of any parameter was determined at the investigator's discretion.
Measured: Baseline (Day 1) up to at least 56 days after last dose of study drug (up to a maximum of 316 days)
Number of Participants With Clinically Significant Change From Baseline in Vital Signs
Vital signs assessments included were systolic and diastolic blood pressure, heart rate, respiratory rate and body temperature. These measurements were taken after the participants had rested for at least 5 minutes in the supine position. Any clinically significant abnormal vital sign assessment required at least one repeat measurement. Clinical significance of any parameter was determined based on investigator's discretion.
Measured: Baseline (Day 1) up to at least 56 days after last dose of study drug (up to a maximum of 316 days)
Number of Participants With Clinically Significant Change From Baseline in Electrocardiogram (ECG)
ECG values included here were Heart rate (HR), PR, QRS, QT, and QTcF intervals, interpretation of the tracings (eg, rhythm, presence of arrhythmia or conduction defects, any evidence of myocardial ischemia/infarction, or ST segment, T-wave, and U-wave abnormalities). Abnormal and clinically significant 12-lead ECG included QT interval corrected for heart rate according to Fridericia's formula (QTcF) > 450 millisecond (ms), QRS interval >= 120 ms, PR interval > 220 ms, based on the average of triplicated ECG, assessed at Screening and Day-1. If any of these test results were out of range, then the test could be repeated once (in triplicate).
Measured: Baseline (Day 1) up to at least 56 days after last dose of study drug (up to a maximum of 316 days)

Secondary outcomes (22)

Maximum GBT021601 Concentration (Cmax) in Plasma, Whole Blood and Red Blood Cells (RBCs): Part A
Cmax was defined as the peak concentration observed directly from the experimental data without any interpolation.
Measured: Pre-dose, 0.25 hour (hr), 0.5 hr, 1 hr, 2 hrs, 4 hrs, 6 hrs, 8 hrs,12 hrs, 24 hrs, 36 hrs, 48 hrs, 72 hrs, 168 hrs, 336 hrs, 504 hrs, 672 hrs, 1008 hrs post-dose on Day 1
Maximum GBT021601 Concentration (Cmax) in Plasma, Whole Blood and Red Blood Cells (RBCs): Part B
Cmax was defined as the peak concentration observed directly from the experimental data without any interpolation.
Measured: Pre-dose, 0.25 hr to 1 hr, 2 to 4 hrs post-dose on Day 56, 63, 70, 77, 84, 91, 98, 105, 112
Maximum GBT021601 Concentration (Cmax) in Plasma, Whole Blood and Red Blood Cells (RBCs): Part C
Cmax was defined as the peak concentration observed directly from the experimental data without any interpolation.
Measured: Pre-dose on Day 1, 14, 28, 42 and 0.25 hr to 1 hr, 2 to 4 hrs post-dose on Day 28 and 42
Minimum GBT021601 Concentration (Cmin) in Plasma, Whole Blood and Red Blood Cells (RBCs): Part B
Cmin was defined as the lowest concentration observed directly from the experimental data without any interpolation.
Measured: Pre-dose, 0.25 hr to 1 hr, 2 to 4 hrs post-dose on Day 56, 63, 70, 77, 84, 91, 98, 105, 112
Minimum GBT021601 Concentration (Cmin) in Plasma, Whole Blood and Red Blood Cells (RBCs): Part C
Cmin was defined as the lowest concentration observed directly from the experimental data without any interpolation.
Measured: Pre-dose on Day 1, 14, 28, 42 and 0.25 hr to 1 hr, 2 to 4 hrs post-dose on Day 28 and 42
Time to Attain Maximum Serum Concentration (Tmax) in Plasma, Whole Blood and Red Blood Cells (RBCs): Part A
Maximum observed concentration was defined as the peak concentration observed directly from the experimental data without any interpolation. The time to the maximum observed concentration was defined as the time corresponding to Cmax.
Measured: Pre-dose, 0.25 hour (hr), 0.5 hr, 1 hr, 2 hrs, 4 hrs, 6 hrs, 8 hrs,12 hrs, 24 hrs, 36 hrs, 48 hrs, 72 hrs, 168 hrs, 336 hrs, 504 hrs, 672 hrs, 1008 hrs post-dose on Day 1
Area Under the Concentration Time Curve From Time Zero to the Next Dose (AUC0-tau) in Plasma, Whole Blood and Red Blood Cells (RBCs): Part A
AUC0-tau was defined from time 0 to time of the last quantifiable concentration and was calculated using the linear or logarithmic trapezoid rule. AUCtau was calculated by using hours*microgram per milliliter (hr*mcg)/mL.
Measured: Pre-dose, 0.25 hour (hr), 0.5 hr, 1 hr, 2 hrs, 4 hrs, 6 hrs, 8 hrs,12 hrs, 24 hrs, 36 hrs, 48 hrs, 72 hrs, 168 hrs, 336 hrs, 504 hrs, 672 hrs, 1008 hrs post-dose on Day 1
Area Under the Serum Concentration Time Curve From Time Zero Extrapolated to Infinite Time (AUCinf) in Plasma, Whole Blood and Red Blood Cells (RBCs): Part A
AUCinf was defined as the area calculated by linear/log trapezoid rule from time 0 to infinity with the area extrapolated from the last quantifiable concentration to infinity.
Measured: Pre-dose, 0.25 hour (hr), 0.5 hr, 1 hr, 2 hrs, 4 hrs, 6 hrs, 8 hrs,12 hrs, 24 hrs, 36 hrs, 48 hrs, 72 hrs, 168 hrs, 336 hrs, 504 hrs, 672 hrs, 1008 hrs post-dose on Day 1
Area Under the Concentration Time Curve From Time Zero up to Time 24 Hours (AUC 0-24) in Plasma, Whole Blood and Red Blood Cells (RBCs): Part A
AUC0-24 was defined as the area under the free plasma concentration time curve from time 0 to 24 hours post-dose.
Measured: Pre-dose, 0.25 hour (hr), 0.5 hr, 1 hr, 2 hrs, 4 hrs, 6 hrs, 8 hrs,12 hrs, 24 hrs post-dose on Day 1
Apparent Oral Clearance (CL/F) in Plasma, Whole Blood and Red Blood Cells (RBCs): Part A
CL/F was a quantitative measure of the rate at which a drug substance was removed from the blood. It was calculated as dose of GBT021601 by AUC from time 0 to infinity.
Measured: Pre-dose, 0.25 hour (hr), 0.5 hr, 1 hr, 2 hrs, 4 hrs, 6 hrs, 8 hrs,12 hrs, 24 hrs, 36 hrs, 48 hrs, 72 hrs, 168 hrs, 336 hrs, 504 hrs, 672 hrs, 1008 hrs post-dose on Day 1
Terminal Elimination Half-Life (t1/2) in Plasma, Whole Blood and Red Blood Cells (RBCs): Part A
t1/2 was the time measured for the plasma concentration to decrease by one half.
Measured: Pre-dose, 0.25 hour (hr), 0.5 hr, 1 hr, 2 hrs, 4 hrs, 6 hrs, 8 hrs,12 hrs, 24 hrs, 36 hrs, 48 hrs, 72 hrs, 168 hrs, 336 hrs, 504 hrs, 672 hrs, 1008 hrs post-dose on Day 1
Apparent Volume of Distribution (Vz/F) in Plasma, Whole Blood and Red Blood Cells (RBCs): Part A
Volume of distribution was defined as the theoretical volume in which the total amount of drug would need to be uniformly distributed to produce the desired plasma concentration of a drug. Vz/F was determined based on the fraction absorbed.
Measured: Pre-dose, 0.25 hour (hr), 0.5 hr, 1 hr, 2 hrs, 4 hrs, 6 hrs, 8 hrs,12 hrs, 24 hrs, 36 hrs, 48 hrs, 72 hrs, 168 hrs, 336 hrs, 504 hrs, 672 hrs, 1008 hrs post-dose on Day 1
Percentage Hemoglobin Occupancy
Percentage hemoglobin occupancy (%Hb Occupancy) refers to the proportion of hemoglobin molecules within red blood cells that were bound to study drug (GBT021601). Cmin and Cmax values was used to calculate %Hb occupancy: %Hb Occupancy = GBT021601*RBC per Mean Corpuscular Hemoglobin Concentration (MCHC).
Measured: Part A: Pre-dose,0.25,0.5,1,2,4, 6,8,12,24,36,48,72,168,336,504,672,1008 hrs on Day 1; Part B: Pre-dose,0.25 to 1,2 to 4 hrs post-dose on Day 56,63,70,77,84,91,98,105,112; Part C:Pre-dose on Day 1,14,28,42 and 0.25 to 1, 2 to 4 hrs post-dose on Day 28,42
Plasma Concentrations Versus Time Summary of GBT021601: Part A
The plasma concentration versus time summary was measured by the amount of specific substance in the bloodstream over the specified timepoint.
Measured: Pre-dose, 0.25 hour (hr), 0.5 hr, 1 hr, 2 hrs, 4 hrs, 6 hrs, 8 hrs,12 hrs, 24 hrs, 36 hrs, 48 hrs, 72 hrs, 168 hrs, 336 hrs, 504 hrs, 672 hrs, 1008 hrs post-dose on Day 1
Plasma Concentrations Versus Time Summary of GBT021601: Part B
The plasma concentration versus time summary was measured by the amount of specific substance in the bloodstream over the specified timepoint.
Measured: Pre-dose, 0.25 hr to 1 hr, 2 to 4 hrs post-dose on Day 56, 63, 70, 77, 84, 91, 98, 105, 112, 140,168, 196, 218
Plasma Concentrations Versus Time Summary of GBT021601: Part C
The plasma concentration versus time summary was measured by the amount of specific substance in the bloodstream over the specified timepoint.
Measured: Pre-dose on Day 1, 14, 28, 42 and 0.25 hr to 1 hr, 2 to 4 hrs post-dose on Day 28, 42, 70, 98
Whole Blood Concentrations Versus Time Summary of GBT021601: Part A
The whole blood concentration versus time summary was measured to find concentration of various components in whole blood that changed over a specified period. This helped to monitor the dynamics of blood components such as hemoglobin levels, hematocrit, or glucose concentration over time.
Measured: Pre-dose, 0.25 hour (hr), 0.5 hr, 1 hr, 2 hrs, 4 hrs, 6 hrs, 8 hrs,12 hrs, 24 hrs, 36 hrs, 48 hrs, 72 hrs, 168 hrs, 336 hrs, 504 hrs, 672 hrs, 1008 hrs post-dose on Day 1
Whole Blood Concentrations Versus Time Summary of GBT021601: Part B
The whole blood concentration versus time summary was measured to find concentration of various components in whole blood that changed over a specified period. This helped to monitor the dynamics of blood components such as hemoglobin levels, hematocrit, or glucose concentration over time.
Measured: Pre-dose, 0.25 hr to 1 hr, 2 to 4 hrs, post-dose on Day 56, 63, 70, 77, 84, 91, 98, 105, 112, 140,168, 196, 218
Whole Blood Concentrations Versus Time Summary of GBT021601: Part C
The whole blood concentration versus time summary was measured to find concentration of various components in whole blood that changed over a specified period. This helped to monitor the dynamics of blood components such as hemoglobin levels, hematocrit, or glucose concentration over time.
Measured: Pre-dose on Day 1, 14, 28, 42 and 0.25 hr to 1 hr, 2 to 4 hrs post-dose on Day 28, 42, 70, 98
Red Blood Cell Concentrations Versus Time Summary of GBT021601: Part A
The RBC concentration versus time summary was measured to identify quantity of RBC in a sample of blood over a specified duration. This analysis helped monitor RBC level over time.
Measured: Pre-dose, 0.25 hour (hr), 0.5 hr, 1 hr, 2 hrs, 4 hrs, 6 hrs, 8 hrs,12 hrs, 24 hrs, 36 hrs, 48 hrs, 72 hrs, 168 hrs, 336 hrs, 504 hrs, 672 hrs, 1008 hrs post-dose on Day 1
Red Blood Cell Concentrations Versus Time Summary of GBT021601: Part B
The RBC concentration versus time summary was measured to identify quantity of RBC in a sample of blood over a specified duration. This analysis helped monitor RBC level over time.
Measured: Pre-dose, 0.25 hr to 1 hr, 2 to 4 hrs post-dose on Day 56, 63, 70, 77, 84, 91, 98, 105, 112, 140,168, 196, 218
Red Blood Cell Concentrations Versus Time Summary of GBT021601: Part C
The RBC concentration versus time summary involved tracking a quantity of RBC in a sample of blood over a specified duration. This analysis helped to monitor RBC level over time.
Measured: Pre-dose on Day 1, 14, 28, 42 and 0.25 hr to 1 hr, 2 to 4 hrs post-dose on Day 28, 42, 70, 98

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

21 May 20216 Dec 2022

First posted30 Jul 2021
Study start21 May 2021
Primary completion6 Dec 2022
Study completion6 Dec 2022

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
Publications (1)Papers the sponsor has linked to this study.
Other trials for Sickle Cell DiseaseStudies of the same condition, open and under way.
More trials run by PfizerThe sponsor's other registered studies.
What the trial phases meanHow a treatment moves from first tests in people to approval.

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design

Study type: Interventional
Phase: Phase 1
Primary purpose: Treatment
Allocation: Non-randomised
Intervention model: Single group
Masking: None (open label)
Enrolment: 6 participants (actual)

IDs, dates and publications

ClinicalTrials.gov ID: NCT04983264
Sponsor's protocol ID: GBT021601-012
Other IDs: C5351002
Status last verified: Dec 2023
First submitted: 27 May 2021
Last updated: 10 Jun 2024
Results posted: Yes, on ClinicalTrials.gov
Data monitoring committee: No
FDA-regulated drug: Yes
FDA-regulated device: No
Individual data sharing: No: Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical\_trials/trial\_data\_and\_results/data\_requests.

Publications

Lisbon EA, Brown RC, Redfern A, Duchin K, Barth A, Roberts ES, Gaputan P, Dufu K, Lo A, Pochron MP, Archer DR, Chin W, Kong K, Washington CB, Adenola A, Zimmerman EI. Safety, Pharmacokinetics, and Pharmacodynamics of Osivelotor for Sickle Cell Disease: First-in-Human Studies in Healthy Participants and Patients. Clin Pharmacol Ther. 2026 Jan;119(1):120-130. doi: 10.1002/cpt.70028. Epub 2025 Sep 2.
PubMed 40891510

Want to know more?

The sponsor has not listed a contact. The official record may have more details.

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

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Study at a glance

From the registry record, last updated by the sponsor on 10 Jun 2024. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: An Intrapatient Single Dose and Multiple Ascending Dose Study to Evaluate the Pharmacokinetics, Safety, Tolerability, and Pharmacodynamics of GBT021601, a Hemoglobin S Polymerization Inhibitor, in Participants With Sickle Cell Disease (SCD)
ClinicalTrials.gov ID: NCT04983264
Acronym / sponsor ID: GBT021601-012
Conditions: Sickle Cell Disease
Phase: Phase 1
Study type: Interventional
Recruitment status: Completed
Enrolment: 6 participants (actual)
Lead sponsor: PfizerIndustry (pharma, biotech, devices)
Study start: 21 May 2021 (actual)
Primary completion: 6 Dec 2022 (actual)
Study completion: 6 Dec 2022 (actual)
First posted: 30 Jul 2021 (actual)
Results: Posted 10 Jun 2024

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

Detailed description

This is an open-label intrapatient single dose followed by a multiple dose escalation study in at least six (6) participants with SCD.

Study design

Primary purpose: Treatment
Allocation: Non-randomised
Intervention model: Single group
Masking: None (open label)
Number of arms: 2

Arm	Type	Receives
Single-dose Period (Part A)	Experimental	Drug: GBT021601Refer to Study Description
Multiple Ascending-dose Period (Part B and Part C)	Experimental	Drug: GBT021601Refer to Study Description

Who may qualify

Ages: 18 to 60 years
Sex: All
Healthy volunteers: Not accepted
Age groups: Adult

Key inclusion criteria (5 listed)

Male or Female with SCD
Participants with SCD ages 18 to 60 years, inclusive.
Participant has provided documented informed consent.
Patients with stable and close to baseline hemoglobin value
Patients on HU should be on stable dose for at least 90 days prior to signing ICF

Key exclusion criteria (4 listed)

Patients had more than 10 VOC within 12 months of screening
Patients who are pregnant or nursing
Patients who receive RBC transfusion therapy regularly or received an RBC transfusion for any reason within 60 days of signing the ICF
Hospitalized for sickle cell crisis or other vaso-occlusive event within 14 days of signing the ICF or within 24 days prior to Day 1 treatment

Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.

Interventions

Intervention	Type	Arms
GBT021601Tablets and capsules which contain GBT021601 drug substance	Drug	Multiple Ascending-dose Period (Part B and Part C), Single-dose Period (Part A)

Primary outcome

Number of Participants With Treatment Emergent Adverse Events (TEAEs) and Serious Adverse Events (SAEs)
Time frame: From first dose of study drug (Day 1) to at least 56 days after last dose of study drug (up to a maximum of 316 days)
An adverse event (AE) was any untoward medical occurrence in a study participant administered a product or medical device; the event need not necessarily have a causal relationship with the treatment or usage. A treatment-emergent AE (TEAE) was an AE that occurs or worsens during the on-treatment period defined as the time from the first dose of study drug through minimum of 56 days after last dose of study treatment. A Serious Adverse Event (SAE) was any untoward medical occurrence at any dose that: resulted in death; was life-threatening experience (immediate risk of death); required inpatient hospitalization or prolongation if existing hospitalization; resulted in persistent or significant disability/ incapacity; resulted in congenital anomaly/birth defect; was considered an important medical event. TEAEs and SAEs were reported for both Sickle Cell Disease (SCD) and non-SCD related events, in this outcome measure.
Number of Participants With Clinically Significant Physical Examination Findings
Time frame: Baseline (Day 1) up to at least 56 days after last dose of study drug (up to a maximum of 316 days)
Physical examination included were general appearance, head, ears, eyes, nose, throat, neck, skin, cardiovascular system, respiratory system, gastrointestinal system, musculoskeletal system, lymph nodes, and nervous system. Clinically significant physical examination abnormalities were considered as adverse events based on investigator's discretion.
Number of Participants With Clinically Significant Change From Baseline in Laboratory Parameters
Time frame: Baseline (Day 1) up to at least 56 days after last dose of study drug (up to a maximum of 316 days)
Laboratory parameters included hematology(hemoglobin,hematocrit,red blood cell count,platelet count,white blood cell count,total neutrophils,eosinophils,monocytes,basophils,lymphocytes);blood chemistry(blood urea,nitrogen, creatinine,glucose,calcium,sodium,potassium,chloride,total bicarbonate,aspartate aminotransferase,alanine aminotransferase,total bilirubin,alkaline phosphatase,uric acid albumin,total protein);urinalysis(decimal logarithm of reciprocal of hydrogen ion activity [pH], glucose, protein, blood,ketones, microscopy[urine tested positive for blood or protein]),urine drug screening:cannabinoids,amphetamines,methamphetamines,opiates,methadone,cocaine,benzodiazepines,phencyclidine,barbiturates,alcohol breath test. Hemoximetry RBC deformability,dense cells test; erythropoietin,follicle stimulating hormone,pregnancy test,Serology panel for HIV 1/2 antibody,Hepatitis A, B and C,SARS CoV-2.Clinical significance of any parameter was determined at the investigator's discretion.
Number of Participants With Clinically Significant Change From Baseline in Vital Signs
Time frame: Baseline (Day 1) up to at least 56 days after last dose of study drug (up to a maximum of 316 days)
Vital signs assessments included were systolic and diastolic blood pressure, heart rate, respiratory rate and body temperature. These measurements were taken after the participants had rested for at least 5 minutes in the supine position. Any clinically significant abnormal vital sign assessment required at least one repeat measurement. Clinical significance of any parameter was determined based on investigator's discretion.
Number of Participants With Clinically Significant Change From Baseline in Electrocardiogram (ECG)
Time frame: Baseline (Day 1) up to at least 56 days after last dose of study drug (up to a maximum of 316 days)
ECG values included here were Heart rate (HR), PR, QRS, QT, and QTcF intervals, interpretation of the tracings (eg, rhythm, presence of arrhythmia or conduction defects, any evidence of myocardial ischemia/infarction, or ST segment, T-wave, and U-wave abnormalities). Abnormal and clinically significant 12-lead ECG included QT interval corrected for heart rate according to Fridericia's formula (QTcF) > 450 millisecond (ms), QRS interval >= 120 ms, PR interval > 220 ms, based on the average of triplicated ECG, assessed at Screening and Day-1. If any of these test results were out of range, then the test could be repeated once (in triplicate).

22 secondary outcomes

Maximum GBT021601 Concentration (Cmax) in Plasma, Whole Blood and Red Blood Cells (RBCs): Part A
Time frame: Pre-dose, 0.25 hour (hr), 0.5 hr, 1 hr, 2 hrs, 4 hrs, 6 hrs, 8 hrs,12 hrs, 24 hrs, 36 hrs, 48 hrs, 72 hrs, 168 hrs, 336 hrs, 504 hrs, 672 hrs, 1008 hrs post-dose on Day 1
Maximum GBT021601 Concentration (Cmax) in Plasma, Whole Blood and Red Blood Cells (RBCs): Part B
Time frame: Pre-dose, 0.25 hr to 1 hr, 2 to 4 hrs post-dose on Day 56, 63, 70, 77, 84, 91, 98, 105, 112
Maximum GBT021601 Concentration (Cmax) in Plasma, Whole Blood and Red Blood Cells (RBCs): Part C
Time frame: Pre-dose on Day 1, 14, 28, 42 and 0.25 hr to 1 hr, 2 to 4 hrs post-dose on Day 28 and 42
Minimum GBT021601 Concentration (Cmin) in Plasma, Whole Blood and Red Blood Cells (RBCs): Part B
Time frame: Pre-dose, 0.25 hr to 1 hr, 2 to 4 hrs post-dose on Day 56, 63, 70, 77, 84, 91, 98, 105, 112
Minimum GBT021601 Concentration (Cmin) in Plasma, Whole Blood and Red Blood Cells (RBCs): Part C
Time frame: Pre-dose on Day 1, 14, 28, 42 and 0.25 hr to 1 hr, 2 to 4 hrs post-dose on Day 28 and 42
Time to Attain Maximum Serum Concentration (Tmax) in Plasma, Whole Blood and Red Blood Cells (RBCs): Part A
Time frame: Pre-dose, 0.25 hour (hr), 0.5 hr, 1 hr, 2 hrs, 4 hrs, 6 hrs, 8 hrs,12 hrs, 24 hrs, 36 hrs, 48 hrs, 72 hrs, 168 hrs, 336 hrs, 504 hrs, 672 hrs, 1008 hrs post-dose on Day 1
Area Under the Concentration Time Curve From Time Zero to the Next Dose (AUC0-tau) in Plasma, Whole Blood and Red Blood Cells (RBCs): Part A
Time frame: Pre-dose, 0.25 hour (hr), 0.5 hr, 1 hr, 2 hrs, 4 hrs, 6 hrs, 8 hrs,12 hrs, 24 hrs, 36 hrs, 48 hrs, 72 hrs, 168 hrs, 336 hrs, 504 hrs, 672 hrs, 1008 hrs post-dose on Day 1
Area Under the Serum Concentration Time Curve From Time Zero Extrapolated to Infinite Time (AUCinf) in Plasma, Whole Blood and Red Blood Cells (RBCs): Part A
Time frame: Pre-dose, 0.25 hour (hr), 0.5 hr, 1 hr, 2 hrs, 4 hrs, 6 hrs, 8 hrs,12 hrs, 24 hrs, 36 hrs, 48 hrs, 72 hrs, 168 hrs, 336 hrs, 504 hrs, 672 hrs, 1008 hrs post-dose on Day 1
Area Under the Concentration Time Curve From Time Zero up to Time 24 Hours (AUC 0-24) in Plasma, Whole Blood and Red Blood Cells (RBCs): Part A
Time frame: Pre-dose, 0.25 hour (hr), 0.5 hr, 1 hr, 2 hrs, 4 hrs, 6 hrs, 8 hrs,12 hrs, 24 hrs post-dose on Day 1
Apparent Oral Clearance (CL/F) in Plasma, Whole Blood and Red Blood Cells (RBCs): Part A
Time frame: Pre-dose, 0.25 hour (hr), 0.5 hr, 1 hr, 2 hrs, 4 hrs, 6 hrs, 8 hrs,12 hrs, 24 hrs, 36 hrs, 48 hrs, 72 hrs, 168 hrs, 336 hrs, 504 hrs, 672 hrs, 1008 hrs post-dose on Day 1
Terminal Elimination Half-Life (t1/2) in Plasma, Whole Blood and Red Blood Cells (RBCs): Part A
Time frame: Pre-dose, 0.25 hour (hr), 0.5 hr, 1 hr, 2 hrs, 4 hrs, 6 hrs, 8 hrs,12 hrs, 24 hrs, 36 hrs, 48 hrs, 72 hrs, 168 hrs, 336 hrs, 504 hrs, 672 hrs, 1008 hrs post-dose on Day 1
Apparent Volume of Distribution (Vz/F) in Plasma, Whole Blood and Red Blood Cells (RBCs): Part A
Time frame: Pre-dose, 0.25 hour (hr), 0.5 hr, 1 hr, 2 hrs, 4 hrs, 6 hrs, 8 hrs,12 hrs, 24 hrs, 36 hrs, 48 hrs, 72 hrs, 168 hrs, 336 hrs, 504 hrs, 672 hrs, 1008 hrs post-dose on Day 1
Percentage Hemoglobin Occupancy
Time frame: Part A: Pre-dose,0.25,0.5,1,2,4, 6,8,12,24,36,48,72,168,336,504,672,1008 hrs on Day 1; Part B: Pre-dose,0.25 to 1,2 to 4 hrs post-dose on Day 56,63,70,77,84,91,98,105,112; Part C:Pre-dose on Day 1,14,28,42 and 0.25 to 1, 2 to 4 hrs post-dose on Day 28,42
Plasma Concentrations Versus Time Summary of GBT021601: Part A
Time frame: Pre-dose, 0.25 hour (hr), 0.5 hr, 1 hr, 2 hrs, 4 hrs, 6 hrs, 8 hrs,12 hrs, 24 hrs, 36 hrs, 48 hrs, 72 hrs, 168 hrs, 336 hrs, 504 hrs, 672 hrs, 1008 hrs post-dose on Day 1
Plasma Concentrations Versus Time Summary of GBT021601: Part B
Time frame: Pre-dose, 0.25 hr to 1 hr, 2 to 4 hrs post-dose on Day 56, 63, 70, 77, 84, 91, 98, 105, 112, 140,168, 196, 218
Plasma Concentrations Versus Time Summary of GBT021601: Part C
Time frame: Pre-dose on Day 1, 14, 28, 42 and 0.25 hr to 1 hr, 2 to 4 hrs post-dose on Day 28, 42, 70, 98
Whole Blood Concentrations Versus Time Summary of GBT021601: Part A
Time frame: Pre-dose, 0.25 hour (hr), 0.5 hr, 1 hr, 2 hrs, 4 hrs, 6 hrs, 8 hrs,12 hrs, 24 hrs, 36 hrs, 48 hrs, 72 hrs, 168 hrs, 336 hrs, 504 hrs, 672 hrs, 1008 hrs post-dose on Day 1
Whole Blood Concentrations Versus Time Summary of GBT021601: Part B
Time frame: Pre-dose, 0.25 hr to 1 hr, 2 to 4 hrs, post-dose on Day 56, 63, 70, 77, 84, 91, 98, 105, 112, 140,168, 196, 218
Whole Blood Concentrations Versus Time Summary of GBT021601: Part C
Time frame: Pre-dose on Day 1, 14, 28, 42 and 0.25 hr to 1 hr, 2 to 4 hrs post-dose on Day 28, 42, 70, 98
Red Blood Cell Concentrations Versus Time Summary of GBT021601: Part A
Time frame: Pre-dose, 0.25 hour (hr), 0.5 hr, 1 hr, 2 hrs, 4 hrs, 6 hrs, 8 hrs,12 hrs, 24 hrs, 36 hrs, 48 hrs, 72 hrs, 168 hrs, 336 hrs, 504 hrs, 672 hrs, 1008 hrs post-dose on Day 1
Red Blood Cell Concentrations Versus Time Summary of GBT021601: Part B
Time frame: Pre-dose, 0.25 hr to 1 hr, 2 to 4 hrs post-dose on Day 56, 63, 70, 77, 84, 91, 98, 105, 112, 140,168, 196, 218
Red Blood Cell Concentrations Versus Time Summary of GBT021601: Part C
Time frame: Pre-dose on Day 1, 14, 28, 42 and 0.25 hr to 1 hr, 2 to 4 hrs post-dose on Day 28, 42, 70, 98

Results and safety

Results posted to the registry on 10 Jun 2024, as reported by the sponsor. Figures are copied from the record, not re-analysed. Full results on ClinicalTrials.gov.

Participant flow

Group	Started	Completed
Part A: Single Dose Period	6	6
Part B: Multiple Ascending- Dose Period	0	0
Part C: Extended Treatment Period	0	0

Primary outcome: Number of Participants With Treatment Emergent Adverse Events (TEAEs) and Serious Adverse Events (SAEs)

Time frame: From first dose of study drug (Day 1) to at least 56 days after last dose of study drug (up to a maximum of 316 days). Count of participants. Unit: Participants

Measure	Part A: Single Dose Period n = 6	Part B: Multiple Ascending- Dose Period n = 6	Part C: Extended Treatment Period n = 4
TEAEs: SCD Related	1	3	1
SAEs: SCD Related	0	2	0
TEAEs: Non-SCD Related	5	5	3
SAEs: Non-SCD Related	0	0	0

Population analysed: Safety population was defined as all participants who received any amount of study drug (GBT021601).

Primary outcome: Number of Participants With Clinically Significant Physical Examination Findings

Time frame: Baseline (Day 1) up to at least 56 days after last dose of study drug (up to a maximum of 316 days). Count of participants. Unit: Participants

Measure	Part A: Single Dose Period n = 6	Part B: Multiple Ascending- Dose Period n = 6	Part C: Extended Treatment Period n = 4
Value	0	0	0

Population analysed: Safety population was defined as all participants who received any amount of study drug (GBT021601).

Primary outcome: Number of Participants With Clinically Significant Change From Baseline in Laboratory Parameters

Time frame: Baseline (Day 1) up to at least 56 days after last dose of study drug (up to a maximum of 316 days). Count of participants. Unit: Participants

Measure	Part A: Single Dose Period n = 6	Part B: Multiple Ascending- Dose Period n = 6	Part C: Extended Treatment Period n = 4
Value	1	0	0

Population analysed: Safety population was defined as all participants who received any amount of study drug (GBT021601).

Primary outcome: Number of Participants With Clinically Significant Change From Baseline in Vital Signs

Time frame: Baseline (Day 1) up to at least 56 days after last dose of study drug (up to a maximum of 316 days). Count of participants. Unit: Participants

Measure	Part A: Single Dose Period n = 6	Part B: Multiple Ascending- Dose Period n = 6	Part C: Extended Treatment Period n = 4
Value	0	0	0

Population analysed: Safety population was defined as all participants who received any amount of study drug (GBT021601).

22 secondary outcomes are reported in the full results.

Adverse events

Time frame: From baseline (Day 1) up to at least 56 days after last dose of study drug (for a maximum of 316 days). Other adverse events reported at 0% frequency or more

Group	Serious adverse events	Other adverse events	Deaths
Part A: Single Dose Period (SCD Related)	0 of 6 (0%)	1 of 6 (16.7%)	0 of 6
Part B: Multiple Ascending- Dose Period (SCD Related)	2 of 6 (33.3%)	2 of 6 (33.3%)	0 of 6
Part C: Extended Treatment Period (SCD Related)	0 of 4 (0%)	1 of 4 (25%)	0 of 4
Part A: Single Dose Period (Non-SCD Related)	0 of 6 (0%)	5 of 6 (83.3%)	0 of 6
Part B: Multiple Ascending- Dose Period (Non-SCD Related)	0 of 6 (0%)	5 of 6 (83.3%)	0 of 6
Part C: Extended Treatment Period (Non-SCD Related)	0 of 4 (0%)	3 of 4 (75%)	0 of 4

Loading the posted results from ClinicalTrials.gov…

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 10 Jun 2024.
Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
Derived from this study: PubMed 40891510Lisbon EA, Brown RC, Redfern A, Duchin K, Barth A, Roberts ES, Gaputan P, Dufu K, Lo A, Pochron MP, Archer DR, Chin W, Kong K, Washington CB, Adenola A, Zimmerman EI. Safety, Pharmacokinetics, and Pharmacodynamics of Osivelotor for Sickle Cell Disease: First-in-Human Studies in Healthy Participants and Patients. Clin Pharmacol Ther. 2026 Jan;119(1):120-130. doi: 10.1002/cpt.70028. Epub 2025 Sep 2.
To obtain contact information for a study center near you, click here.Link provided by the sponsor.
Individual participant dataSharing planned: No. Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical_trials/trial_data_and_results/data_requests.

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Referral and contact

AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.

Pfizer Pfizer CT.gov Call Center study director

Pfizer

3 sites in 1 country: see every site and its status.

Questions about this trial

What is this clinical trial studying?

A Phase 1 study testing GBT021601 in people with Sickle Cell Disease, run by Pfizer at 3 sites in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 5 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 10 Jun 2024. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 3 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

Yes. Results are posted in the registry (first posted 10 Jun 2024). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Number of Participants With Treatment Emergent Adverse Events (TEAEs) and Serious Adverse Events (SAEs) (time frame: From first dose of study drug (Day 1) to at least 56 days after last dose of study drug (up to a maximum of 316 days)). The study lists 5 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT04983264, which also lists 1 linked publication.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 10 Jun 2024.