Sickle Cell DiseasePhase 3RESOLVENCT05561140
Resolution of Sickle Cell Leg Ulcers With Voxelotor
A Phase 3 study testing Voxelotor Oral Tablet in people with Sickle Cell Disease and Leg Ulcers, run by Pfizer at 23 sites in 3 countries.
Trial summary
This study is a Phase 3, multicenter, randomized, placebo-controlled study to evaluate the efficacy of voxelotor and standard of care for the treatment of leg ulcers in participants with sickle cell disease. Read more about this study
- Who is it for?
- Ages 12 years and older
- Conditions the study is for
- Sickle Cell Disease, Leg Ulcers
- What is being tested?
- Voxelotor Oral Tablet
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 88 participants
- Where
- 23 sitesin 3 countries
- Study dates
- 30 May 2022to 22 Oct 2024
- Phase
- Phase 3
- 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 12 years and older
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Who may be able to join
- Male or female participants with documented diagnosis of SCD (HbSS, HbS/β0 thalassemia)
- Age 12 years and older
- At least 1 cutaneous ulcer(s) on the lower extremity (leg, ankle, or dorsum of foot) that meets the following criteria:
- Duration: ≥ 2 weeks and < 6 months at Screening, and
- Size: > 2 cm2 prior to randomization
- Written informed consent (≥ 18 years) or parental/guardian consent and participant assent (≥ 12-17 years) per IEC policy and requirements, consistent with ICH guidelines
Who cannot join
- Target ulcer(s) healed by ≥ 25% during the standard of care run-in period prior to randomization
- Active infection/purulence at ulcer site, or exposed tendon or bone at the ulcer site, based on Investigator's clinical judgment
- Current osteomyelitis at or near the ulcer site
- Known vascular abnormalities that would preclude healing in the opinion of the Investigator (eg, pre-existing severe arterial insufficiency in the affected limb)
- Serum albumin < 2.0 g/dL
- RBC transfusion within 60 days of initiation of study drug
Show all 14Show fewer
- Receiving regularly scheduled RBC transfusion therapy (also termed chronic, prophylactic, or preventive transfusion) during the study
- Planned elective surgery within the next 6 months
- Anemia due to bone marrow failure (eg, myelodysplasia)
- Absolute reticulocyte count < 100 × 109/L
- Screening alanine aminotransferase (ALT) > 4 × upper limit of normal (ULN)
- Severe renal dysfunction (estimated glomerular filtration rate [eGFR] < 30 mL/min/1.73 m2 by Schwartz formula) or is on chronic dialysis
- Clinically significant bacterial, fungal, parasitic, or viral infection that requires therapy
- Other protocol-defined Eligibility Criteria that apply
Trial locations and contacts
23 sites in 3 countries.
23 sites in 3 countries
Brazil10 sites
Hospital das Clinicas da Universidade Federal de Minas Gerais
Belo Horizonte, Minas Gerais, 30130-100
Hospital das Clínicas da Faculdade de Medicina da Universidade de Sao Paulo
Cerqueira Cesar - Sao Paulo, São Paulo, 05403-000
Multihemo Servicos Medicos S/A
Recife, Pernambuco, 50070-460
Hospital das Clinicas da Faculdade de Medicina de Ribeirão Preto da Universidade de Sao Paulo
Ribeirão Preto, São Paulo, 14051-140
Complexo Hospitalar Universitário Professor Edgard Santos- Universidade Federal Da Bahia
Salvador, Estado de Bahia, 40110-060
Universidade Federal Da Bahia Hospital Universitário Professor Edgard Santos
Salvador, Estado de Bahia, 40110-060
Hospital São Rafael
Salvador, Estado de Bahia, 41253-190
Esho Empresa De Servicos Hospitalares S.A/ Hospital Samaritano Higienopolis
São Paulo, 01232-010
Hospital das Clínicas da Faculdade de Medicina da Universidade de Sao Paulo
São Paulo, 01246-000
Hospital das Clínicas da Faculdade de Medicina da Universidade de Sao Paulo
São Paulo, 05403-000
Nigeria7 sites
SYNLAB
Abuja, Federal Capital Territory, 902101
University of Calabar Teaching Hospital
Calabar, Cross River State, 540281
SYNLAB
Gwagwalada, Abuja, 902101
University of Abuja Teaching Hospital
Gwagwalada, Federal Capital Territory, 902101
Barau Dikko Teaching Hospital/Kaduna State University
Kaduna, 800212
Aminu kano Teaching Hospital
Kano, 700233
Lagos University Teaching Hospital
Lagos, 100254
Kenya6 sites
KEMRI Centre for Clinical Research Butere County Hospital
Butere, Kakamega County, 50100
KEMRI Kondele Children's Hospital within Jaramogi Oginga Odinga Teaching and Referral Hospital.
Kisumu, 40100
Gertrude's Children's Hospital
Nairobi, 00100
KEMRI-Centre for Respiratory Diseases Research-Nairobi
Nairobi, 00100
Strathmore University Medical Centre
Nairobi, 00200
KEMRI-CRDR, KEMRI Clinical Research Annex
Siaya, 40600
About this study
Official title: A Phase 3, Multicenter, Randomized, Double-Blind, Placebo-Controlled Trial to Evaluate the Efficacy of Voxelotor for the Treatment of Leg Ulcers in Patients With Sickle Cell Disease
This study is a Phase 3, multicenter, randomized, placebo-controlled study to evaluate the efficacy of voxelotor and standard of care for the treatment of leg ulcers in participants with sickle cell disease. The study is divided into a 5 study periods: Screening, Run-in, Randomized Treatment, Open-label Treatment, and Follow-up/End of Study (EOS).
The study will be conducted in approximately 80 eligible participants at approximately 20 global clinical trial sites.
- Conditions
- Sickle Cell Disease, Leg Ulcers
- Being tested
- Voxelotor Oral Tablet, Placebo
- Keywords
- Sickle Cell Disease, SCD
- Medical subject headings
- Anemia, Sickle Cell, Leg Ulcer
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Voxelotor Oral TabletDrug
Synthetic small molecule supplied as 500 mg tablets, administered Orally
PlaceboOther
Placebo
| Study group | Role | What they receive |
|---|---|---|
| Voxeletor + SOC (Standard of Care) | Experimental | Not described Receives: Drug: Voxelotor Oral Tablet |
| Placebo + SOC (Standard of Care) | Placebo comparator | Not described Receives: Other: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Percentage of Participants Who Achieved Resolution of the Target Ulcers by Week 12 in Randomized Treatment Period
An ulcer qualified as a target ulcer, if met the following criteria: a) duration of ulcer was greater than equal to (>=) 2 weeks and less than (<) 6 months at screening; b) healed by <25 percent (%) during the SOC run-in phase prior to randomization; c) size was greater than (>2) square centimeters (cm^2) at any visit, prior to randomization. Resolution of the target ulcer was defined as skin re-epithelialization confirmed at 2 consecutive study visits, 2 weeks apart during the 12-week randomized treatment period. For participants with more than one target ulcer, all target ulcers must be confirmed resolved in order for the participant to be a responder.
Measured: Through Week 12 of randomized treatment period
Secondary outcomes (3)
Time to Resolution of Target Ulcers up to Week 12 in Randomized Treatment Period
An ulcer qualified as a target ulcer, if met the following criteria: a) duration of ulcer was >=2 weeks and <6 months at screening; b) healed by <25% during the SOC run-in phase prior to randomization; c) size was >2 cm^2 at any visit, prior to randomization. Resolution of the target ulcer was defined as skin re-epithelialization confirmed at 2 consecutive study visits, 2 weeks apart during the 12-week randomized treatment period. Time to resolution of target ulcers was defined as the first time of the observed ulcer was resolved. For participants with more than one target ulcer, time to resolution of target ulcers was defined as time to the last target ulcer confirmed resolved. For participants who did not have the last target ulcer confirmed resolved by Week 12 or who were discontinued from study, the time to resolution was censored. Median time to event was evaluated using Kaplan-Meier method.
Measured: From Day 1 to censoring date before Week 12 or maximum up to Week 12 of randomized treatment period, whichever occurred first
Change From Baseline in Total Surface Area of Target Ulcers at Week 12 in Randomized Treatment Period
An ulcer qualified as a target ulcer, if met the following criteria: a) duration of ulcer was >=2 weeks and <6 months at screening; b) healed by <25% during the SOC run-in phase prior to randomization; c) size was >2 cm^2 at any visit, prior to randomization.
Measured: Baseline, Week 12 of randomized treatment period
Percentage of Participants With New Ulcers by Week 12 in Randomized Treatment Period
New ulcers were defined as ulcer(s) that were not captured at visit 1/screening. In this outcome measure, participants with occurrence of new ulcers during 12 weeks of treatment were considered.
Measured: Through Week 12 of randomized treatment period
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted30 Sep 2022
- Study start30 May 2022
- Primary completion26 Jun 2024
- Study completion22 Oct 2024
Why it stopped: Emerging clinical data evaluated by Pfizer and shared with regulatory authorities indicates that the risk profile of voxelotor in people with SCD exceeds the benefits observed in previously generated global research and requires further assessment.
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.
- 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 3
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 88 participants (actual)
Sponsor and investigators
- Lead sponsor
- Pfizer
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Pfizer CT.gov Call Center, Study director, Pfizer
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05561140
- Sponsor's protocol ID
- GBT440-042
- Other IDs
- C5341026
- Acronym
- RESOLVE
- Status last verified
- Jun 2025
- First submitted
- 27 Sep 2022
- Last updated
- 9 Jul 2025
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
- 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.
Study at a glance
From the registry record, last updated by the sponsor on 9 Jul 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase 3, Multicenter, Randomized, Double-Blind, Placebo-Controlled Trial to Evaluate the Efficacy of Voxelotor for the Treatment of Leg Ulcers in Patients With Sickle Cell Disease
- ClinicalTrials.gov ID
- NCT05561140
- Acronym / sponsor ID
- RESOLVE / GBT440-042
- Conditions
- Sickle Cell Disease, Leg Ulcers
- Keywords
- Sickle Cell Disease, SCD
- Phase
- Phase 3
- Study type
- Interventional
- Recruitment status
- TerminatedReason stopped: Emerging clinical data evaluated by Pfizer and shared with regulatory authorities indicates that the risk profile of voxelotor in people with SCD exceeds the benefits observed in previously generated global research and requires further assessment.
- Enrolment
- 88 participants (actual)
- Lead sponsor
- PfizerIndustry (pharma, biotech, devices)
- Study start
- 30 May 2022 (actual)
- Primary completion
- 26 Jun 2024 (actual)
- Study completion
- 22 Oct 2024 (actual)
- First posted
- 30 Sep 2022 (actual)
- Results
- Posted 9 Jul 2025
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study is a Phase 3, multicenter, randomized, placebo-controlled study to evaluate the efficacy of voxelotor and standard of care for the treatment of leg ulcers in participants with sickle cell disease. The study is divided into a 5 study periods: Screening, Run-in, Randomized Treatment, Open-label Treatment, and Follow-up/End of Study (EOS).
The study will be conducted in approximately 80 eligible participants at approximately 20 global clinical trial sites.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, investigator)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Voxeletor + SOC (Standard of Care) | Experimental | Drug: Voxelotor Oral Tablet |
| Placebo + SOC (Standard of Care) | Placebo comparator | Other: Placebo |
Who may qualify
- Ages
- 12 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
Key inclusion criteria (6 listed)
- Male or female participants with documented diagnosis of SCD (HbSS, HbS/β0 thalassemia)
- Age 12 years and older
- At least 1 cutaneous ulcer(s) on the lower extremity (leg, ankle, or dorsum of foot) that meets the following criteria:
- Written informed consent (≥ 18 years) or parental/guardian consent and participant assent (≥ 12-17 years) per IEC policy and requirements, consistent with ICH guidelines
Key exclusion criteria (14 listed)
- Target ulcer(s) healed by ≥ 25% during the standard of care run-in period prior to randomization
- Active infection/purulence at ulcer site, or exposed tendon or bone at the ulcer site, based on Investigator's clinical judgment
- Current osteomyelitis at or near the ulcer site
- Known vascular abnormalities that would preclude healing in the opinion of the Investigator (eg, pre-existing severe arterial insufficiency in the affected limb)
- Serum albumin < 2.0 g/dL
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 |
|---|---|---|
| Voxelotor Oral TabletSynthetic small molecule supplied as 500 mg tablets, administered Orally | Drug | Voxeletor + SOC (Standard of Care) |
| PlaceboPlacebo | Other | Placebo + SOC (Standard of Care) |
Primary outcome
Percentage of Participants Who Achieved Resolution of the Target Ulcers by Week 12 in Randomized Treatment Period
Time frame: Through Week 12 of randomized treatment period
An ulcer qualified as a target ulcer, if met the following criteria: a) duration of ulcer was greater than equal to (>=) 2 weeks and less than (<) 6 months at screening; b) healed by <25 percent (%) during the SOC run-in phase prior to randomization; c) size was greater than (>2) square centimeters (cm^2) at any visit, prior to randomization. Resolution of the target ulcer was defined as skin re-epithelialization confirmed at 2 consecutive study visits, 2 weeks apart during the 12-week randomized treatment period. For participants with more than one target ulcer, all target ulcers must be confirmed resolved in order for the participant to be a responder.
3 secondary outcomes
Time to Resolution of Target Ulcers up to Week 12 in Randomized Treatment Period
Time frame: From Day 1 to censoring date before Week 12 or maximum up to Week 12 of randomized treatment period, whichever occurred first
Change From Baseline in Total Surface Area of Target Ulcers at Week 12 in Randomized Treatment Period
Time frame: Baseline, Week 12 of randomized treatment period
Percentage of Participants With New Ulcers by Week 12 in Randomized Treatment Period
Time frame: Through Week 12 of randomized treatment period
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 9 Jul 2025.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- 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.
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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 CT.gov Call Center study director
Pfizer
23 sites in 3 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 3 study testing Voxelotor Oral Tablet in people with Sickle Cell Disease and Leg Ulcers, run by Pfizer at 23 sites in 3 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 6 inclusion and 14 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: stopped early, as of the sponsor's last update on 9 Jul 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 23 sites in Brazil, Nigeria, Kenya. 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 phase mean?
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?
Yes. Results are posted in the registry (first posted 9 Jul 2025). 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?
Percentage of Participants Who Achieved Resolution of the Target Ulcers by Week 12 in Randomized Treatment Period (time frame: Through Week 12 of randomized treatment period). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 9 Jul 2025.