Assessing Physical Function in Sickle Cell Patients Taking Voxelotor

August 28, 2026 updated by: Inova Health Care Services

Assessing Functional Capacity in Sickle Cell Patients Receiving Voxelotor

Voxelotor is a novel hemoglobin polymerization inhibitor which has been demonstrated to reduce hemolysis and improve hemoglobin levels. There have been numerous studies examining the clinical impact of voxelotor in sickle cell disease (SCD) patients, but there are few published reports on the effects of treatment on physical function in patients with SCD. The hypothesis to be tested is that anemic SCD patients will have improvements in performance after 6 months of voxelotor treatment.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
6

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • United States
    • Virginia
      • Falls Church, Virginia, United States, 22042
        • Inova Schar Cancer Institute

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Study Population

This study will enroll adults diagnosed with various genotypes of sickle cell disease including HbSS, HbSC or HbS beta thalassemia.

Description

Inclusion Criteria:

  1. Provision of signed and dated informed consent form
  2. Stated willingness to comply with all study procedures and availability for the duration of the study
  3. Male or female,
  4. aged 18-65 years
  5. Diagnosis of sickle cell disease with HbSS, HbSc, HbS-beta thalassemia genotypes
  6. Hemoglobin level of 6 g/dL - 10.5 g/dL
  7. Between 0 and 10 vaso-occlusive (VOC) episodes in previous 12 months
  8. Ability to take oral medication and be willing to adhere to the voxelotor regimen
  9. For females of reproductive potential, they will be educated to avoid pregnancy during study period and for one month after due to limited data surrounding pregnancy and voxelotor
  10. For males of reproductive potential: use of condoms or other methods to ensure effective contraception with partner
  11. Agreement to adhere to Lifestyle Considerations (see section 5.3) throughout study duration

Exclusion Criteria:

  1. Hemoglobin results < 6 g/dL or > 10.5 g/dL
  2. Patients receiving hydroxyurea who have had a dose change within the prior 3 months
  3. Females who are breastfeeding or pregnant
  4. Patients who are receiving regularly scheduled blood (RBC) transfusion therapy (also termed chronic, prophylactic, or preventive transfusion) within 30 days of 6MWT
  5. Any form of hepatic dysfunction as demonstrated by alanine aminotransferase (ALT) >4 × ULN or Child-Pugh Class C
  6. Acute kidney injury or chronic renal disease with estimated glomerular filtration rate<30mL/min/1.73 m2
  7. Current or previous diagnosis of malignancy within the last two years excluding local therapy for non-melanoma skin malignancy
  8. Unstable cardiopulmonary disease within the last 6 months prior to study enrollment
  9. Any conditions including behavioral or medical that in the opinion of the investigator, may negatively impact informed consent, participation and study interpretation
  10. Current use of commercially available voxelotor
  11. Prior hypersensitivity to voxelotor or its excipients
  12. Patients with baseline gait and other physical impairments that would limit 6MWT and other functional assessment at discretion of the investigator
  13. Patients who on day of assessment present with vaso-occlusive crisis or rate their pain greater than 6 on a scale of 1-10 using the Numeric Rating Scale will not be assessed that day and re-screened at the investigator's discretion.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Voxeletor
Drug: Voxelotor
Voxelotor is administered orally at a dose of 1500mg daily.
Other Names:
  • Oxbryta

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Participant's Physical Performance Using 6 Minutes Walk Test (6MWT) Pre and Post Treatment with Voxelotor.
Time Frame: 6 months from the treatment initiation
The 6MWT is a sensitive objective assessment of functional exercise capacity which assess distance walked over 6 minutes.This test detects minor and moderate functional impairment resulting from treatment with Voxelotor.
6 months from the treatment initiation

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
The Change in the Quality of Life as assessed by Sheehan Disability Scale (SDS) During the 6 Months Trial Period.
Time Frame: 6 months from the treatment initiation
The SDS is a short self-reporting questionnaire that assess functional impairment in work/school, social and family life. The assessment scale has a total score of 30 (0 unimpaired and 30 extremely impaired).
6 months from the treatment initiation

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Inova Health Care Services

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Pfizer

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Sheinei Alan, Inova Schar Cancer Institute

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
October 23, 2023

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
September 17, 2025

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
March 5, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
August 7, 2023

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 1, 2023

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
September 5, 2023

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
August 31, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 28, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
August 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • U23-02-4988

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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