A Phase 2/3 Study of Osivelotor in Adult and Adolescent Participants With SCD

A Phase 2/3 study testing Osivelotor in people with Sickle Cell Disease, run by Pfizer at 80 sites in 7 countries.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Trial summary

The purpose of this study is to evaluate the safety, tolerability, efficacy, pharmacokinetics and pharmacodynamics of osivelotor. Read more about this study

Who is it for?: Ages 12 years and older
Conditions the study is for: Sickle Cell Disease
What is being tested?: Osivelotor
Type of treatment: Pill or oral medicine
Could I receive a placebo?: Yes, some participants may receive a placebo
How many people: 389 participants
Where: 80 sitesin 7 countries
Study dates: 22 Sep 2022to 31 Dec 2032
Phase: Phase 2/3
Are there results?: Not yet: the study is under way

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 12 years and older
All sexes
No healthy volunteers
Child, Adult, Older adult

Who may be able to join

Part A and Part B:
Male or female with SCD, HbSS and HbSB-zero
Participants with Hemoglobin ≥ 5.5 and ≤ 10.5 g/dL during Screening and considered stable by the Investigator.
For participants taking hydroxyurea and/or L-glutamine, the dose must be stable for at least 90 days prior to signing the ICF or assent and with no anticipated need for dose adjustments during the study in the opinion of the Investigator.
Part B:
Participants with SCD ages 12 years and older, inclusive at screening.

Show all 9Show fewer

Participants with more than or equal to 2 and ≤ 10 VOCs within 12 months of Screening.
OLE:
Participants who have completed the Part B successfully will be eligible.

Who cannot join

Part A and Part B:
Participants who had more than 10 VOC within 12 months of screening
Female participant who is breastfeeding or pregnant
Participants who receive RBC transfusion therapy regularly or received an RBC transfusion ---for any reason within 90 days of Day 1
Participants hospitalized for sickle cell crisis or other vaso-occlusive event within 14 days of signing the ICF or anytime during the screening period.
Participants in Sub-Saharan Africa or who have relocated from Sub-Saharan Africa within 6 months.

Show all 10Show fewer

OLE:
Have any unresolved clinically significant adverse event, laboratory abnormality, or safety finding from Part B that, in the opinion of the Investigator, increases the risk of study drug administration.
Met permanent treatment discontinuation criteria during Part B.
Have withdrawn consent or are unable to comply with study procedure

Trial locations and contacts

80 sites in 7 countries. Contact the study team or a site near you to ask about taking part.

Pfizer Pfizer CT.gov Call Center contact

1-800-718-1021

ClinicalTrials.gov_Inquiries@pfizer.com

Country

City, postcode or hospital

Sites recruiting now only

80 sites in 7 countries

United States46 sites, 35 recruiting

Children's Center for Advanced Pediatrics
Atlanta, Georgia, 30329
Recruiting
LSU Health Baton Rouge-North Clinic
Baton Rouge, Louisiana, 70805
Active, not recruiting
Our Lady of the Lake Hospital, Inc.
Baton Rouge, Louisiana, 70808
Active, not recruiting
Our lady of the Lake Hospital
Baton Rouge, Louisiana, 70808
Active, not recruiting
Clinical & Translational Research Center (CTRC)
Chapel Hill, North Carolina, 27514
Not yet recruiting
UNC Health
Chapel Hill, North Carolina, 27514
Not yet recruiting
UNC Eastowne Medical Office Building - Consent Only
Chapel Hill, North Carolina, 27517
Not yet recruiting
University of Illinois at Chicago Clinical Research Center
Chicago, Illinois, 60612
Recruiting
University of Illinois Hospital and Health Sciences System - Investigational Drug Services (IDS)
Chicago, Illinois, 60612
Recruiting
University of Illinois Hospital and Health Sciences System
Chicago, Illinois, 60612
Recruiting
Prisma Health Laurens County Hospital
Clinton, South Carolina, 29325
Recruiting
Children's Hospital of Michigan
Detroit, Michigan, 48201
Not yet recruiting
Alpha Clinical Research Georgia
Dunwoody, Georgia, 30350
Active, not recruiting
Duke University IDS Pharmacy
Durham, North Carolina, 27710
Recruiting
Duke University Medical Center
Durham, North Carolina, 27710
Recruiting
Inova Schar Cancer Institute
Fairfax, Virginia, 22031
Recruiting
Southern Specialty Research
Flowood, Mississippi, 39232
Recruiting
ECU Physicians, Brody Outpatient Clinic
Greenville, North Carolina, 27834
Recruiting
Prisma Health - Upstate
Greenville, South Carolina, 29605
Recruiting
Prisma Health Greenville Memorial Hospital
Greenville, South Carolina, 29605
Recruiting
Prisma Health Outpatient Radiology - Greenville
Greenville, South Carolina, 29605
Recruiting
Prisma Health Patewood Hospital
Greenville, South Carolina, 29615
Recruiting
Prisma Health Greer Memorial Hospital
Greer, South Carolina, 29650
Recruiting
Connecticut Children's Medical Center
Hartford, Connecticut, 06106
Not yet recruiting
McGovern Medical School at UTHealth
Houston, Texas, 77030
Active, not recruiting
Memorial Hermann Hospital, Texas Medical Center - Clinical Research Unit (CRU)
Houston, Texas, 77030
Active, not recruiting
The University of Texas Health Science Center at Houston
Houston, Texas, 77030
Active, not recruiting
UT Physicians Comprehensive Sickle Cell Clinic
Houston, Texas, 77030
Active, not recruiting
University Health
Kansas City, Missouri, 64108
Recruiting
Mississippi Center for Advanced Medicine
Madison, Mississippi, 39110
Active, not recruiting
AMR Clinical
Mobile, Alabama, 36608
Recruiting
UNC IDS
Morrisville, North Carolina, 27560
Not yet recruiting
Jack & Sheryl Morris Cancer Center
New Brunswick, New Jersey, 08901
Recruiting
Robert Wood Johnson University Hospital
New Brunswick, New Jersey, 08901
Recruiting
Rutgers Cancer Institute of New Jersey
New Brunswick, New Jersey, 08901
Recruiting
Smilow Cancer Hospital
New Haven, Connecticut, 06511
Not yet recruiting
University Medical Center New Orleans
New Orleans, Louisiana, 70112
Active, not recruiting
Icahn School of Medicine at Mount Sinai
New York, New York, 10029
Recruiting
Edward Jenner Research Group LLC.
Plantation, Florida, 33317
Recruiting
Sonar Clinical Research
Riverdale, Georgia, 30274
Active, not recruiting
Prisma Health Hillcrest Hospital
Simpsonville, South Carolina, 29681
Recruiting
Great Lakes Research Institute, Flourish Detroit
Southfield, Michigan, 48075
Not yet recruiting
Jacobi Medical Center
The Bronx, New York, 10461
Recruiting
Prisma Health North Greenville Hospital
Travelers Rest, South Carolina, 29690
Recruiting
Pediatric Hematology / Oncology a division of Kidz Medical services
West Palm Beach, Florida, 33407
Recruiting
St. Mary's Medical Center
West Palm Beach, Florida, 33407
Recruiting

Other trials in United States

Brazil13 sites, 11 recruiting

Multihemo Servicos Medicos S/A
Recife, Pernambuco, 50070-460
Not yet recruiting
Hospital Das Clinicas da Faculdade de Medicina de Ribeirão Preto - USP
Ribeirão Preto, São Paulo, 14051-140
Not yet recruiting
Instituto Estadual de Hematologia Arthur Siqueira Cavalcanti - HEMORIO
Rio de Janeiro, 20211-030
Not yet recruiting
CPHosp Medicina, Ensino e Pesquisa Ltda
São, São Paulo, 01228-000
Not yet recruiting
Fundacao Faculdade Regional de Medicina de Sao Jose do Rio Preto
São José do Rio Preto, São Paulo, 15090-000
Recruiting
BP A Beneficência Portuguesa de São Paulo
São Paulo, São Paulo, 01321 001
Not yet recruiting
BP - A Beneficência Portuguesa de São Paulo
São Paulo, São Paulo, 01323-900
Not yet recruiting
Casa de Saude Santa Marcelina
São Paulo, São Paulo, 08270-070
Not yet recruiting
Casa de Saude Santa Marcelina
São Paulo, São Paulo, 08270-120
Not yet recruiting
Esho Empresa de Servicos Hospitalares S A
São Paulo, SÃO Paulo- Brasil, 01232-011
Not yet recruiting
Esho Empresa de Servicos Hospitalares S A
São Paulo, 01232-010
Not yet recruiting
Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo
São Paulo, 05403-000
Active, not recruiting
Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo
São Paulo, 05403-010
Active, not recruiting

Other trials in Brazil

United Kingdom7 sites, 7 recruiting

University Hospitals Bristol and Weston NHS Foundation Trust
Bristol, BS2 8ED
Recruiting
Bristol Royal Infirmary
Bristol, BS2 8EX
Recruiting
University College London Hospital
London, NW1 2PG
Recruiting
Guy's & St Thomas' NHS Foundation Trust
London, SE1 9RT
Recruiting
King's College Hospital NHS Foundation Trust
London, SE5 9RS
Recruiting
Hammersmith Hospital, Imperial College Healthcare NHS Trust
London, W12 0HS
Recruiting
Hammersmith Hospital
London, W12 0HS
Recruiting

Other trials in United Kingdom

India6 sites, 6 recruiting

AIIMS, Bhubaneswar
Bhubaneswar, Odisha, 751019
Not yet recruiting
Chopda Medicare & Research Centre Pvt. Ltd: Magnum Heart Institute
Nashik, Maharashtra, 422005
Recruiting
AIIMS Delhi
New Delhi, National Capital Territory of Delhi, 110029
Not yet recruiting
AIIMS Raipur
Raipur, Chhattisgarh, 492099
Not yet recruiting
Nirmal Hospital Pvt Ltd
Surat, Gujarat, 395002
Recruiting
Haemato Oncology Care Centre
Vadodara, Gujarat, 390020
Recruiting

Other trials in India

Kenya4 sites

KEMRI/CRDR, Siaya, KEMRI Clinical Research Annex
Kisumu, Siaya County, 40600
Completed
Gertrude's Children's Hospital
Nairobi, 00100
Completed
Kenya Medical Research Institute - Centre for Respiratory Disease Research
Nairobi, 00100
Completed
Center for Research In Therapeutic Sciences (CREATES), Strathmore University Medical Centre
Nairobi, 00200
Completed

Other trials in Kenya

Nigeria3 sites

University College Hospital Ibadan
Ibadan, Oyo/ibadan North, 200212
Completed
Aminu Kano Teaching Hospital
Kano, 700233
Completed
Lagos University Teaching Hospital
Lagos, 100254
Completed

Other trials in Nigeria

Saudi Arabia1 site, 1 recruiting

King Khalid University Hospital
Riyadh, Riyadh Region, 11472
Not yet recruiting

Other trials in Saudi Arabia

About this study

Official title: A PHASE 2/3 RANDOMIZED, MULTICENTER STUDY OF OSIVELOTOR ADMINISTERED ORALLY TO ADULT AND ADOLESCENT PARTICIPANTS WITH SICKLE CELL DISEASE

The purpose of this study is to evaluate the safety, tolerability, efficacy, pharmacokinetics and pharmacodynamics of osivelotor.

Read the detailed description

This is a three-part, multicenter, Phase 2/3 study of orally administered osivelotor in participants with sickle cell disease (SCD).

Part A will evaluate the safety, tolerability, and efficacy of osivelotor in adult participants with SCD to determine an optimal dose. (Complete) Part B will evaluate the efficacy of osivelotor versus placebo in adult and adolescent participants with SCD for 48 weeks.

Open Label Extension (OLE) will evaluate the long-term safety and hematologic responses of open-label osivelotor in adult and adolescent participants having completed Part B.

Conditions: Sickle Cell Disease
Being tested: Osivelotor
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.

OsivelotorDrug
Also called PF-07940367 or GBT021601
Tablets which contain drug substance

Study groups in NCT05431088
Study group	Role	What they receive
Part B	Placebo comparator	Study drug arm: Adult participants will receive osivelotor at 300 mg QD loading dose for 7 days followed by 150 mg QD through Week 48. Adolescent participant dose will be defined in a future protocol amendment. Placebo arm: Participants will receive placebo tablets for 48 weeks. Receives: Drug: Osivelotor
OLE	Experimental	Adult Participants will receive 150 mg open-label osivelotor up to 2 years after the last participant's visit in Part B or when the drug is commercially available in that region. The appropriate doses for adolescents will be defined in a future protocol amendment. Receives: Drug: Osivelotor
Part A	Active comparator	Initially, participants will be randomized 1:1 to 100 mg and 150 mg daily. Upon review of the 150 mg safety data from at least 6 participants, there will be 1:1:1 randomization: 100 mg, 150 mg, and up to 200 mg. Participants will then receive maintenance once daily doses through Week 12. Receives: Drug: Osivelotor

What is being measured

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

Part A
Number of adult participants with change from baseline in hemoglobin (Hb) through week 12 as measured by change in osivelotor concentrations from baseline or percentage change from baseline of clinical measures of anemia Hb and hemolysis (including indirect bilirubin, reticulocytes and lactate dehydrogenase).
Measured: Through week 12
Part B
Co-primary endpoints: Hb response (increase from baseline of >1 g/dL) at Week 48 (based on average of Hb levels at Week 40 and Week 48) and the Annualized rate of VOC through end of Week 48.
A VOC is defined as an acute episode of pain that:
- Has no medically determined cause other than a vaso-occlusive event, and
- Results in a visit to a medical facility (hospitalization, emergency department, urgent care center, outpatient clinic, or infusion center), and
- Requires parenteral narcotic agents, parenteral nonsteroidal anti-inflammatory drugs (NSAIDs), or an increase in treatment with oral narcotics.
Complicated VOCs of acute chest syndrome (ACS), hepatic sequestration, splenic sequestration, priapism, and dactylitis that meet the requirements listed above will be included in this co-primary endpoint.
Measured: Through week 48
OLE
Incidence of Treatment Emergent Adverse Events:
- Incidence of SAEs
- Incidence of AEs leading to discontinuation
- Change from baseline in laboratory parameters.
Measured: Approximately 24 months after last patient enrolled

Timeline

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

22 Sep 202231 Dec 2032

First posted24 Jun 2022
Study start22 Sep 2022
Primary completion30 Dec 2030 (estimated)
Study completion31 Dec 2032 (estimated)

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Publications (2)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 2/3
Primary purpose: Treatment
Allocation: Randomised
Intervention model: Parallel groups
Masking: Quadruple blind
Who is masked: Participant, Care provider, Investigator, Outcomes assessor
Enrolment: 389 participants (estimated)

IDs, dates and publications

ClinicalTrials.gov ID: NCT05431088
Sponsor's protocol ID: GBT021601-021
Other IDs: C5351004, 2023-508766-14-00, 2023
Status last verified: Aug 2026
First submitted: 21 Jun 2022
Last updated: 18 Aug 2026
Results posted: No
Data monitoring committee: Yes
FDA-regulated drug: Yes
FDA-regulated device: No
Individual data sharing: Yes: 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

Li Z, Alt C, Dufu K, Hutchaleelaha A, Xu Q, Zhang X, Li CM, Rademacher P, Bosmajian C, Pochron MP, Partridge JR, Oksenberg D, Cathers BE. Discovery of Osivelotor (GBT021601): A Potent, Next-Generation Sickle Hemoglobin Polymerization Inhibitor. ACS Med Chem Lett. 2025 Jul 8;16(8):1526-1532. doi: 10.1021/acsmedchemlett.5c00076. eCollection 2025 Aug 14.
PubMed 40832524
Obadina M, Wilson S, Derebail VK, Little J. Emerging Therapies and Advances in Sickle Cell Disease with a Focus on Renal Manifestations. Kidney360. 2023 Jul 1;4(7):997-1005. doi: 10.34067/KID.0000000000000162. Epub 2023 May 31.
PubMed 37254256

Interested in taking part?

Pfizer Pfizer CT.gov Call Center

1-800-718-1021

ClinicalTrials.gov_Inquiries@pfizer.com

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?

See sites and contacts

Active, not recruitingPhase 1/2
Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of Long-term Mitapivat Dosing in Subjects With Stable Sickle Cell Disease: An Extension of a Phase I Pilot Study of Mitapivat
Sickle Cell Disease, Hemolytic Anemia
RecruitingObservational study
HPC Offered for PRESERVE Expansion
Bone Marrow Transplant (BMT)
RecruitingPhase 1
Study to Evaluate the Safety and Tolerability of Escalating Doses of Fostamatinib in Subjects With Stable Sickle Cell Disease
Sickle Cell Disorders, Sickle Cell Disease
RecruitingPhase 4
Clinical and Biomarker Effects of Depot Medroxyprogesterone Acetate in Females With Sickle Cell Disease
Sickle Cell Disease (SCD), Vaso-Occlusive Pain Episode in Sickle Cell Disease
Not yet recruitingPhase 1
Buprenorphine for the Management of Pain in Children With Sickle Cell Disease
Sickle Cell Disease (SCD), Sickle Cell Disease Vaso-occlusive Crisis

All Sickle Cell Disease trials

Study at a glance

From the registry record, last updated by the sponsor on 18 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: A PHASE 2/3 RANDOMIZED, MULTICENTER STUDY OF OSIVELOTOR ADMINISTERED ORALLY TO ADULT AND ADOLESCENT PARTICIPANTS WITH SICKLE CELL DISEASE
ClinicalTrials.gov ID: NCT05431088
Acronym / sponsor ID: GBT021601-021
Conditions: Sickle Cell Disease
Phase: Phase 2/3
Study type: Interventional
Recruitment status: Recruiting
Enrolment: 389 participants (estimated)
Lead sponsor: PfizerIndustry (pharma, biotech, devices)
Study start: 22 Sep 2022 (actual)
Primary completion: 30 Dec 2030 (estimated)
Study completion: 31 Dec 2032 (estimated)
First posted: 24 Jun 2022 (actual)
Results: Not posted in the source record

Clinical summary

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

The purpose of this study is to evaluate the safety, tolerability, efficacy, pharmacokinetics and pharmacodynamics of osivelotor.

Detailed description

This is a three-part, multicenter, Phase 2/3 study of orally administered osivelotor in participants with sickle cell disease (SCD).

Open Label Extension (OLE) will evaluate the long-term safety and hematologic responses of open-label osivelotor in adult and adolescent participants having completed Part B.

Study design

Primary purpose: Treatment
Allocation: Randomised
Intervention model: Parallel groups
Masking: Quadruple blind (participant, care provider, investigator, outcomes assessor)
Number of arms: 3

Arm	Type	Receives
Part B	Placebo comparator	Drug: OsivelotorStudy drug arm: Adult participants will receive osivelotor at 300 mg QD loading dose for 7 days followed by 150 mg QD through Week 48. Adolescent participant dose will be defined in a future protocol amendment. Placebo arm: Participants will receive placebo tablets for 48 weeks.
OLE	Experimental	Drug: OsivelotorAdult Participants will receive 150 mg open-label osivelotor up to 2 years after the last participant's visit in Part B or when the drug is commercially available in that region. The appropriate doses for adolescents will be defined in a future protocol amendment.
Part A	Active comparator	Drug: OsivelotorInitially, participants will be randomized 1:1 to 100 mg and 150 mg daily. Upon review of the 150 mg safety data from at least 6 participants, there will be 1:1:1 randomization: 100 mg, 150 mg, and up to 200 mg. Participants will then receive maintenance once daily doses through Week 12.

Who may qualify

Ages: 12 years and older
Sex: All
Healthy volunteers: Not accepted
Age groups: Child, Adult, Older adult

Key inclusion criteria (9 listed)

Male or female with SCD, HbSS and HbSB-zero
Participants with Hemoglobin ≥ 5.5 and ≤ 10.5 g/dL during Screening and considered stable by the Investigator.
For participants taking hydroxyurea and/or L-glutamine, the dose must be stable for at least 90 days prior to signing the ICF or assent and with no anticipated need for dose adjustments during the study in the opinion of the Investigator.
Participants with SCD ages 12 years and older, inclusive at screening.
Participants with more than or equal to 2 and ≤ 10 VOCs within 12 months of Screening.

Key exclusion criteria (10 listed)

Participants who had more than 10 VOC within 12 months of screening
Female participant who is breastfeeding or pregnant
Participants who receive RBC transfusion therapy regularly or received an RBC transfusion ---for any reason within 90 days of Day 1
Participants hospitalized for sickle cell crisis or other vaso-occlusive event within 14 days of signing the ICF or anytime during the screening period.
Participants in Sub-Saharan Africa or who have relocated from Sub-Saharan Africa within 6 months.

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
OsivelotorAlso: PF-07940367 or GBT021601Tablets which contain drug substance	Drug	OLE, Part A, Part B

Primary outcome

Part A
Time frame: Through week 12
Number of adult participants with change from baseline in hemoglobin (Hb) through week 12 as measured by change in osivelotor concentrations from baseline or percentage change from baseline of clinical measures of anemia Hb and hemolysis (including indirect bilirubin, reticulocytes and lactate dehydrogenase).
Part B
Time frame: Through week 48
Co-primary endpoints: Hb response (increase from baseline of >1 g/dL) at Week 48 (based on average of Hb levels at Week 40 and Week 48) and the Annualized rate of VOC through end of Week 48. A VOC is defined as an acute episode of pain that: * Has no medically determined cause other than a vaso-occlusive event, and * Results in a visit to a medical facility (hospitalization, emergency department, urgent care center, outpatient clinic, or infusion center), and * Requires parenteral narcotic agents, parenteral nonsteroidal anti-inflammatory drugs (NSAIDs), or an increase in treatment with oral narcotics. Complicated VOCs of acute chest syndrome (ACS), hepatic sequestration, splenic sequestration, priapism, and dactylitis that meet the requirements listed above will be included in this co-primary endpoint.
OLE
Time frame: Approximately 24 months after last patient enrolled
Incidence of Treatment Emergent Adverse Events: * Incidence of SAEs * Incidence of AEs leading to discontinuation * Change from baseline in laboratory parameters.

Results and safety

This study is still under way. Results are not available in the source record yet.

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 18 Aug 2026.
Derived from this study: PubMed 40832524Li Z, Alt C, Dufu K, Hutchaleelaha A, Xu Q, Zhang X, Li CM, Rademacher P, Bosmajian C, Pochron MP, Partridge JR, Oksenberg D, Cathers BE. Discovery of Osivelotor (GBT021601): A Potent, Next-Generation Sickle Hemoglobin Polymerization Inhibitor. ACS Med Chem Lett. 2025 Jul 8;16(8):1526-1532. doi: 10.1021/acsmedchemlett.5c00076. eCollection 2025 Aug 14.
Derived from this study: PubMed 37254256Obadina M, Wilson S, Derebail VK, Little J. Emerging Therapies and Advances in Sickle Cell Disease with a Focus on Renal Manifestations. Kidney360. 2023 Jul 1;4(7):997-1005. doi: 10.34067/KID.0000000000000162. Epub 2023 May 31.
To obtain contact information for a study center near you, click here.Link provided by the sponsor.
Individual participant dataSharing planned: Yes. 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.

Related trials for Sickle Cell Disease

Active, not recruitingPhase 1/2
Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of Long-term Mitapivat Dosing in Subjects With Stable Sickle Cell Disease: An Extension of a Phase I Pilot Study of Mitapivat
Sickle Cell Disease, Hemolytic Anemia
RecruitingObservational study
HPC Offered for PRESERVE Expansion
Bone Marrow Transplant (BMT)
RecruitingPhase 1
Study to Evaluate the Safety and Tolerability of Escalating Doses of Fostamatinib in Subjects With Stable Sickle Cell Disease
Sickle Cell Disorders, Sickle Cell Disease
RecruitingPhase 4
Clinical and Biomarker Effects of Depot Medroxyprogesterone Acetate in Females With Sickle Cell Disease
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Not yet recruitingPhase 1
Buprenorphine for the Management of Pain in Children With Sickle Cell Disease
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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.

Pfizer Pfizer CT.gov Call Center contact

1-800-718-1021

ClinicalTrials.gov_Inquiries@pfizer.com

Pfizer CT.gov Call Center study director

Pfizer

80 sites in 7 countries: see every site and its status.

Questions about this trial

What is this clinical trial studying?

A Phase 2/3 study testing Osivelotor in people with Sickle Cell Disease, run by Pfizer at 80 sites in 7 countries.

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 9 inclusion and 10 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: looking for participants now, as of the sponsor's last update on 18 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 80 sites in United States, Brazil, United Kingdom, India, Kenya and 2 more countries. 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. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this combined phase mean?

Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.

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

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

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

Contact Pfizer Pfizer CT.gov Call Center (1-800-718-1021, ClinicalTrials.gov_Inquiries@pfizer.com), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Part A (time frame: Through week 12). The study lists 3 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 NCT05431088, which also lists 2 linked publications.

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 18 Aug 2026.