Oxbryta® Product Registry An Observational Study Designed to Evaluate the Effect of Oxbryta in Individuals With SCD (PROSPECT)

An Open Label, Observational, Prospective Registry of Participants With Sickle Cell Disease (SCD) Treated With Oxbryta® (Voxelotor)

This registry is an observational study designed to evaluate the effect of Oxbryta in individuals with SCD in a real-world setting.

Study Overview

• Status: Terminated
• Conditions: Sickle Cell Disease
• Intervention / Treatment: Drug: Oxbryta® (voxelotor) 500mg Tablets

Detailed Description

The study will be conducted at approximately 45 sites in the United States.

This registry is an observational study to evaluate the effects of Oxbryta in individuals with SCD. Any participant who is currently taking Oxbryta, or has been prescribed and will initiate treatment with Oxbryta, is eligible to participate. Eligible participants will receive treatment with Oxbryta as prescribed by their physician, as part of their usual care. Participants will be treated and evaluated per standard of care (SOC) and at the physician's discretion. This study will collect data that are recorded in the participants' medical records and other secondary data sources. Study data will be collected at regular intervals and entered in case report forms (CRFs) via an electronic data capture (EDC) system by the study staff. Participants will be considered to be on study for up to 5 years after their first dose of Oxbryta treatment, or until they withdraw their consent to participate, or are discontinued from the study. Treatment, including interruptions and restarting treatment, will continue at the discretion of the treating physician, and there are no pre-defined treatment requirements. Participants may receive any additional medications prescribed by their treating physician, or have any medical interventions that are deemed appropriate by the treating physician or study doctor. The participant or treating physician may discontinue Oxbryta at any time. Participants who discontinue treatment with Oxbryta earlier than 5 years will continue to be followed on study to collect clinical and quality of life (QoL) outcomes for up to 5 years after their first dose of Oxbryta treatment. Participant safety and tolerability will be assessed throughout the study data collection period by the study doctor and reported to the Sponsor.

• Study Type: Observational
• Enrollment (Actual): 265

Contacts and Locations

Study Locations

• United States
  • Alabama
    • Mobile, Alabama, United States, 36617
      • University of South Alabama
  • Arizona
    • Phoenix, Arizona, United States, 85016
      • Phoenix Children's Hospital
  • California
    • La Jolla, California, United States, 92093-0987
      • University of California, San Diego
    • Orange, California, United States, 92868
      • Center for Inherited Blood Disorders
    • Palo Alto, California, United States, 94304
      • Stanford Children's Hospital
    • Palo Alto, California, United States, 94304
      • Bass Center for Childhood Cancer and Blood Disorders (Stanford Lucile Packard Children's Hospital)
    • Palo Alto, California, United States, 94304
      • Department of Pediatrics, Hematology section
  • Connecticut
    • Farmington, Connecticut, United States, 06030
      • University of Connecticut Health
    • Farmington, Connecticut, United States, 06030-1163
      • University of Connecticut Health
  • Delaware
    • Wilmington, Delaware, United States, 19803
      • Nemours Alfred I duPont Hospital for Children
    • Wilmington, Delaware, United States, 19803
      • Nemours Children's Health, Wilmington
  • Florida
    • Hollywood, Florida, United States, 33023
      • Foundation for Sickle Cell Disease Research
    • Jacksonville, Florida, United States, 32207
      • Nemours Children's Specialty Care
    • Miami, Florida, United States, 33136
      • University of Miami Hospital
  • Georgia
    • Augusta, Georgia, United States, 30912
      • Augusta University
    • Augusta, Georgia, United States, 30912
      • Augusta University - Clinical Trials Office (clinic)
  • Illinois
    • Chicago, Illinois, United States, 60612
      • University of Illinois Hospital and Health Sciences System
    • Chicago, Illinois, United States, 60612
      • University of Illinois Hospital and Health Sciences System(UI Health)
    • Chicago, Illinois, United States, 60612
      • University of Illinois at Chicago (UIC) Clinical Research Center
    • Chicago, Illinois, United States, 60612
      • University of Illinois at Chicago (UIC) Sickle Cell Center
  • Maryland
    • College Park, Maryland, United States, 21201
      • University of Maryland Medical Center
  • Massachusetts
    • Boston, Massachusetts, United States, 02118
      • Boston University Medical Center
  • Mississippi
    • Madison, Mississippi, United States, 39110
      • Mississippi Center For Advanced Medicine
  • New Jersey
    • Newark, New Jersey, United States, 07112
      • Newark Beth Israel Medical Center
  • New York
    • The Bronx, New York, United States, 10467
      • Montefiore Medical Center
  • North Carolina
    • Charlotte, North Carolina, United States, 28204
      • Levine Cancer Institute
    • Durham, North Carolina, United States, 27710
      • Duke University Medical Center
    • Durham, North Carolina, United States, 27710
      • Duke University Hospital
    • Greenville, North Carolina, United States, 27834
      • ECU Health Medical Center
    • Greenville, North Carolina, United States, 27834-4300
      • East Carolina University
    • Greenville, North Carolina, United States, 27834
      • ECU Health Medical Center Laboratory
  • Pennsylvania
    • Pittsburgh, Pennsylvania, United States, 15213
      • UPMC Presbyterian
    • Pittsburgh, Pennsylvania, United States, 15261
      • University of Pittsburgh Medical Center (UPMC)
    • Pittsburgh, Pennsylvania, United States, 14213
      • UPMC Montefiore Hospital
    • Pittsburgh, Pennsylvania, United States, 15123
      • UPMC Sickle Cell Center
  • South Carolina
    • Charleston, South Carolina, United States, 29425
      • Medical University of South Carolina
    • Charleston, South Carolina, United States, 29425
      • Medical University of South Carolina Shawn Jenkins Women's and Children's Hospital
  • Tennessee
    • Memphis, Tennessee, United States, 38105
      • St. Jude Children's Research Hospital
  • Texas
    • Austin, Texas, United States, 78723
      • Dell Children's Medical Center
    • Austin, Texas, United States, 78723
      • Children's Blood and Cancer Center at Dell Children's Medical Center
    • Houston, Texas, United States, 77030
      • University of Texas Health Science Center at Houston
  • Virginia
    • Fairfax, Virginia, United States, 22031
      • Inova Schar Cancer Institute
    • Falls Church, Virginia, United States, 22042-2325
      • INOVA Health

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

All patients at each participating study site who have been treated with Oxbryta will be considered for inclusion in this study.

Description

Inclusion Criteria:

• Participants who meet all the following criteria will be eligible for enrollment:

  1. Willing and able to provide written informed consent (aged ≥ 18 years), parental/ guardian consent and participant assent (aged ≥ 12 to <18 years) per local regulations, or pediatric participants (aged 4 to <12 years) with parental/guardian consent per Institutional Review Board (IRB) policy and requirements, consistent with ICH guidelines
  2. Male or female participants with documented diagnosis of sickle cell disease (all genotypes)
  3. Undergoing treatment with Oxbryta according to the Oxbryta USPI

Exclusion Criteria:

• Participants meeting any of the following criteria will not be eligible for study enrollment:

  1. Current participation in an investigation clinical trial or expanded access program, in which the participant may be receiving voxelotor treatment.
  2. Medical, psychological, or behavioral condition that, in the opinion of the study doctor, would confound or interfere with evaluation of safety and/or effectiveness of the study drug, prevent compliance with the study protocol; preclude informed consent; or render the participant unable/unlikely to comply with the study procedures

Study Plan

How is the study designed?

Design Details

• Observational Models: Other
• Time Perspectives: Prospective

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Oxbryta Product Registry	Drug: Oxbryta® (voxelotor) 500mg Tablets; Participants will receive treatment with Oxbryta as prescribed by their physician, as part of their usual care. Participants will be treated and evaluated per standard of care (SOC) and at the physician's discretion. There are no pre-defined treatment requirements.; Other Names: Voxelotor; Oxbryta®

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Hemoglobin From Pre-Oxbryta Treatment (Baseline) Through Month 60 Post-Oxbryta	The pre-Oxbryta (baseline) value was the latest measurement on or prior to the first dose of Oxbryta. Post-Oxbryta value was the measurement for multiple assessments at the same specific visit, the average was used.	Pre-Oxbryta (baseline) 3, 6, 9, 12, 18, 24, 30, 36, 42, 48, 54, 60 months post-Oxbryta
Change in Percent Reticulocyte Count From Pre-Oxbryta Treatment (Baseline) Through Month 60 Post-Oxbryta	The pre-Oxbryta (baseline) value was the latest measurement on or prior to the first dose of Oxbryta. Post-Oxbryta value was the measurement for multiple assessments at the same specific visit, the average was used.	Pre-Oxbryta (baseline) 3, 6, 9, 12, 18, 24, 30, 36, 42, 48, 54, 60 months post-Oxbryta
Change in Absolute Reticulocyte Count From Pre-Oxbryta Treatment (Baseline) Through Month 60 Post-Oxbryta	The pre-Oxbryta (baseline) value was the latest measurement on or prior to the first dose of Oxbryta. Post-Oxbryta value was the measurement for multiple assessments at the same specific visit, the average was used.	Pre-Oxbryta (baseline) 3, 6, 9, 12, 18, 24, 30, 36, 42, 48, 54, 60 months post-Oxbryta
Change in Bilirubin (Total, Direct and Indirect) Level From Pre-Oxbryta Treatment (Baseline) Through Month 60 Post-Oxbryta	The pre-Oxbryta (baseline) value was the latest measurement on or prior to the first dose of Oxbryta. Post-Oxbryta value was the measurement for multiple assessments at the same specific visit, the average was used. Abbreviations used: overall number of participants analyzed=N and Number analyzed= n	Pre-Oxbryta (baseline) 3, 6, 9, 12, 18, 24, 30, 36, 42, 48, 54, 60 months post-Oxbryta
Change in Iron Overload (Ferritin Levels) From Pre-Oxbryta Treatment (Baseline) Through Month 60 Post-Oxbryta	The pre-Oxbryta (baseline) value was the latest measurement on or prior to the first dose of Oxbryta. Post-Oxbryta value was the measurement for multiple assessments at the same specific visit, the average was used.	Pre-Oxbryta (baseline) 3, 6, 9, 12, 18, 24, 30, 36, 42, 48, 54, 60 months post-Oxbryta
Change in Iron Overload as Measured by T2-weighted Magnetic Resonance Imaging (MRI) From Pre-Oxbryta Treatment (Baseline) Through Month 60 Post-Oxbryta	The pre-Oxbryta (baseline) value was the latest measurement on or prior to the first dose of Oxbryta. Post-Oxbryta value was the measurement for multiple assessments at the same specific visit, the average was used.	Pre-Oxbryta (baseline) up to 60 months post-Oxbryta
Change in Serum Creatinine Level From Pre-Oxbryta Treatment (Baseline) Through Month 60 Post-Oxbryta	The pre-Oxbryta (baseline) value was the latest measurement on or prior to the first dose of Oxbryta. Post-Oxbryta value was the measurement for multiple assessments at the same specific visit, the average was used.	Pre-Oxbryta (baseline) 3, 6, 9, 12, 18, 24, 30, 36, 42, 48, 54, 60 months post-Oxbryta
Change in Albumin Creatinine Ratio (ACR) From Pre-Oxbryta Treatment (Baseline) Through Month 54 Post-Oxbryta	The pre-Oxbryta (baseline) value was the latest measurement on or prior to the first dose of Oxbryta. Post-Oxbryta value was the measurement for multiple assessments at the same specific visit, the average was used.	Pre-Oxbryta (baseline) 3, 6, 9, 12, 18, 24, 30, 36, 42, 48, 54 months post-Oxbryta
Number of Participants According to Hemoglobinuria Results Post-Oxbryta	Hemoglobinuria was defined as urine dipstick results positive for blood +1 or greater and <=2 red blood cells (RBC) by high power field. Number of participants according to hemoglobinuria results (none/negative, trace, 1+, 2+, 3+, other: large, moderate, small, small=0-3, hereditary persistence of fetal hemoglobin [HPF], missing) was reported in this outcome measure. Small corresponded to trace or 1+ on dipstick, medium indicated 2+, large indicated 3+ or higher on dipstick. The pre-Oxbryta (baseline) value was the latest measurement on or prior to the first dose of Oxbryta. Post-Oxbryta value was the measurement for multiple assessments at the same specific visit, the average was used.	Pre-Oxbryta (baseline) 3, 6, 9, 12, 18, 24, 30, 36, 42, 48, 54, 60 months post-Oxbryta
Change in Serum Cystatin C Results From Pre-Oxbryta Treatment (Baseline) Through Month 30 Post-Oxbryta	The pre-Oxbryta (baseline) value was the latest measurement on or prior to the first dose of Oxbryta. Post-Oxbryta value was the measurement for multiple assessments at the same specific visit, the average was used.	Pre-Oxbryta (baseline) 3, 6, 12, 18, 24, 30 months post-Oxbryta
Number of Participants According to Estimated Glomerular Filtration Rate (GFR) Results Post-Oxbryta	Estimated GFR was calculated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. Number of participants according to estimated GFR results (stage 1 [G1] - GFR >=90 milliliter/minute [mL/min] per 1.73 square meters [m^2], stage 2 [G2] - GFR 60 to 89 mL/min per 1.73 m^2, stage 3a [G3a] - GFR 45 to 59 mL/min per 1.73 m^2, stage 3b [G3b] - GFR 30 to 44 mL/min per 1.73 m^2, stage 4 [G4] - GFR 15 to 29 mL/min per 1.73 m^2, stage 5 [G5] - GFR < 15 mL/min per 1.73 m^2 or treatment by dialysis, missing) was reported descriptively in this outcome measure. Stages 1 and 2 indicate mild damage, while stages 3 to 5 reflected progressive severity, leading to potential renal failure. The pre-Oxbryta (baseline) value was the latest measurement on or prior to the first dose of Oxbryta. Post-Oxbryta value was the measurement for multiple assessments at the same specific visit, the average was used.	Pre-Oxbryta (baseline) 3, 6, 9, 12, 18, 24, 30, 36, 42, 48, 54, 60 months post-Oxbryta
Number of Participants With SCD Complications	SCD complications included acute pain crisis, acute chest syndrome (ACS), priapism, stroke, chronic or end stage kidney disease iron overload, leg ulcers, cardiac malfunction and pulmonary hypertension (PH) and RBC transfusions.	From date of first Oxbryta treatment through the end of study (up to Month 60)
Number of Participants With Treatment Initiation or Modification of SCD-related Medications	Number of participants with treatment initiation or modification of SCD related medications is reported in this outcome measure.	From date of first Oxbryta treatment through the end of study (up to Month 60)
Number of Participants With Red Blood Cell (RBC) Transfusions	Number of participants with RBC transfusions is reported in this outcome measure.	From date of first Oxbryta treatment through the end of study (up to Month 60)
Number of Participants According to Responses to Patient Global Impression of Change (PGIC) at Month 3 Through Month 60	PGIC was a single question that reflected a participant's or caregiver's belief about the effectiveness of treatment with Oxbryta on a 7-point scale depicting a participant's rating of overall improvement. Participants/caregivers rated their change as "very much improved," "much improved," "minimally improved," "no change," "minimally worse," "much worse," or "very much worse".	Month 3, 6, 9, 12, 18, 24, 30, 36, 42, 48, 54, 60
Number of Participants According to Responses to Clinical Global Impression of Change (CGIC) at Month 3 Through Month 60	CGIC was a brief, stand-alone assessment of the clinician's view of the participant's global functioning prior to and after initiating Oxbryta. The CGI provided an overall clinician-determined summary measure that took into account all available information, including a knowledge of the participant's history, psychosocial circumstances, symptoms, behavior, and the impact of the symptoms on the participant's ability to function. Participants rated their change as "very much improved," "much improved," "minimally improved," "no change," "minimally worse," "much worse," "very much worse," or "not assessed".	Month 3, 6, 9, 12, 18, 24, 30, 36, 42, 48, 54, 60
Number of Participants With Serious Adverse Events (SAEs) According to Severity	An SAE was defined as any untoward medical occurrence that, at any dose, met one or more of the following criteria - resulted in death, was life-threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in persistent or significant disability/incapacity, was a congenital anomaly/birth defect and other important medical events. Severity was classified using common terminology criteria for adverse events (CTCAE), version 5.0, where Grade 1 = mild, Grade 2 = moderate, Grade 3 = severe. Mild - SAEs does not interfere with participant's usual function b) moderate - SAEs interferes to some extent with participant's usual function c) severe - SAEs interferes significantly with participant's usual function.	From date of first Oxbryta treatment up to end of study (up to Month 60)
Number of Participants With Adverse Events (AEs) According to Severity	An AE was any untoward medical occurrence in a participant or clinical investigational participant administered a medicinal product and which did not necessarily have a causal relationship with this treatment. Severity was classified using CTCAE, version 5.0, where Grade 1 = mild, Grade 2 = moderate, Grade 3 = severe. AEs are classified according to the severity in 3 categories a) mild - AEs does not interfere with participant's usual function b) moderate - AEs interferes to some extent with participant's usual function c) severe - AEs interferes significantly with participant's usual function. AEs included both SAEs and non-SAEs.	From date of first Oxbryta treatment up to end of study (up to Month 60)
Number of Participants With AEs Leading to Dose Modification or Discontinuation of Oxbryta	An AE was any untoward medical occurrence in a participant or clinical investigational participant administered a medicinal product and which does not necessarily have a causal relationship with this treatment. Number of participants with AEs leading to dose modification or discontinuation of Oxbryta were reported in this outcome measure.	From date of first Oxbryta treatment up to end of study (up to Month 60)
Number of Participants With Positive Pregnancy Test and Fertility Complications	Number of participants with positive pregnancy test and fertility complications were reported in this outcome measure.	From date of first Oxbryta treatment up to end of study (up to Month 60)

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Number of Outpatient Visits From Pre-Oxbryta Treatment	Outpatient visits (including infusion center, acute care, or telemedicine visit) were planned to be analyzed.	From date of first Oxbryta treatment through the end of study (up to Month 60)
Change in Number of Emergency Department (ED) Visits From Pre-Oxbryta Treatment	ED visits were planned to be analyzed in this outcome measure.	From date of first Oxbryta treatment through the end of study (up to Month 60)
Change in Number of Hospitalizations From Pre-Oxbryta Treatment	Number of hospitalizations were planned to be analyzed.	From date of first Oxbryta treatment through the end of study (up to Month 60)
Change in Home Oxygen Supplementation From Pre-Oxbryta Treatment		From date of first Oxbryta treatment through the end of study (up to Month 60)
Number of Participants With Renal Dialysis		From date of first Oxbryta treatment through the end of study (up to Month 60)

Collaborators and Investigators

• Sponsor: Pfizer
• Collaborators: Pfizer
• Investigators: Study Director: Pfizer CT.gov Call Center, Pfizer

Publications and helpful links

Helpful Links

• To obtain contact information for a study center near you, click here.

Study record dates

Study Major Dates

• Study Start (Actual): February 4, 2022
• Primary Completion (Actual): October 10, 2024
• Study Completion (Actual): October 10, 2024

Study Registration Dates

• First Submitted: June 4, 2021
• First Submitted That Met QC Criteria: June 10, 2021
• First Posted (Actual): June 18, 2021

Study Record Updates

• Last Update Posted (Actual): December 31, 2025
• Last Update Submitted That Met QC Criteria: December 10, 2025
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Keywords: Registry Sickle Cell Disease
• Additional Relevant MeSH Terms: Genetic Diseases, Inborn; Hematologic Diseases; Anemia, Hemolytic, Congenital; Anemia, Hemolytic; Anemia; Hemoglobinopathies; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Hemic and Lymphatic Diseases; Anemia, Sickle Cell; voxelotor
• Other Study ID Numbers: GBT440-4R2; C5341019 (Other Identifier: Alias Study Number)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: 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.

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