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Completed Phase 2 Interventional Results available

Fixed Dose Flavonoid Isoquercetin on Thrombo-Inflammatory Biomarkers in Subjects With Stable Sickle Cell Disease

ClinicalTrials.gov ID: NCT04514510

Public ClinicalTrials.gov record NCT04514510. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.

ClinicalTrials.gov public records Last synced Sep 10, 2026, 5:16 AM EDT

Data is sourced from official ClinicalTrials.gov public API records. Always review the official ClinicalTrials.gov record for the latest information.

Official title

A Study to Evaluate the Effects of Fixed Dose Flavonoid Isoquercetin on Thrombo-Inflammatory Biomarkers in Subjects With Stable Sickle Cell Disease

Brief summary

Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.

Background: Sickle cell disease (SCD) is an inherited hemoglobin disorder. People with SCD have an increased chance for getting blood clots. Researchers want to see if a dietary supplement called isoquercetin can decrease levels of inflammation and blood clotting in people with SCD. Objective: To see how isoquercetin works in people with SCD. Eligibility: Adults age 18-70 years old who have SCD and are in a steady-state (have not experienced a pain crisis in the last 60 days and, if taking hydroxyurea, have not had a dose change in the past 90 days). Design: Participants will be screened with a physical exam, medical history, medicine review, and blood tests. Participants will be put in 1 of 2 treatment groups. They will take 4 capsules of isoquercetin or placebo all at once, by mouth, every day for 4 weeks. They will get a pill dispenser and keep a medicine diary. Participants may have an optional near infrared spectroscopy (NIRS) test to measure how treatment affects blood flow. In this test, probes will be placed on the skin to measure tissue oxygen level and blood flow. A blood pressure cuff placed on the arm will be filled with air briefly to restrict the blood flow in the arm (for up to 5 minutes) and then released. Participants may also be asked to breathe at a certain rate or hold their breath for as long as they can during measurements. Participants will take folic acid once a day. Participants will have an end-of-study drug visit. They will discuss any side effects and repeat some of the screening tests. They may have an additional optional NIRS test. About a month after the end of study drug visit, participants will be contacted by phone to see if they have any side effects. Those who do may have a follow-up visit. At this visit, they may have additional blood tests performed. Participation will last from 8 to 12 weeks.

Study identification

NCT ID
NCT04514510
Recruitment status
Completed
Study type
Interventional
Phase
Phase 2
Enrollment
46 participants

Conditions and interventions

Interventions

Drug

Eligibility (public fields only)

Age range
18 Years to 70 Years
Sex
All
Healthy volunteers
Healthy volunteers not accepted

This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.

Study timeline

Start date
Nov 1, 2020
Primary completion
Jun 12, 2022
Completion
Jul 6, 2022
Last update posted
Jan 1, 2024

2020 – 2022

United States locations

U.S. sites
1
U.S. states
1
U.S. cities
1
Facility City State ZIP Site status
National Institutes of Health Clinical Center Bethesda Maryland 20892

Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.

About this trial record page

What this page shows
Public field values for ClinicalTrials.gov record NCT04514510, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
What this page does not do
No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
Where the data comes from
Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
Last refresh
Last update posted Jan 1, 2024 · Synced Sep 10, 2026

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Open the official record

The complete protocol, eligibility criteria, and contact information for NCT04514510 live on ClinicalTrials.gov.

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