High school senior, trumpet player, and actual Oxbryta patient

About the Oxbryta Clinical Trial*

Hemoglobin Diagram

About the Oxbryta Clinical Trial*

Oxbryta was studied in a trial in which 90 patients received Oxbryta (daily dosage of 1500 mg) and 92 patients received a placebo (sugar pill).*

The trial included patients ages 12 and up who took the medication daily for 24 weeks. Oxbryta trials are currently ongoing to watch the progress of patients taking Oxbryta for longer than 24 weeks.

*Patients who were already taking hydroxyurea at the start of the clinical trial continued to do so for the entire 24-week trial period.
Increased Levels of Hemogoblin

Hemoglobin levels

Clinical Trial Target

Roughly 5 out of 10 patients who received Oxbryta reached the clinical trial's target goal for improvement in hemoglobin levels.

One of the goals of the clinical trial was to find out if treatment with Oxbryta helped hemoglobin levels rise more than 1 gram per deciliter from where they were before taking Oxbryta.

During the clinical trial, 5 out of 10 patients (51.1%) taking Oxbryta reached this goal vs 6.5% of the patients taking placebo.

On average, hemoglobin levels increased by 1.14 grams per deciliter for patients on Oxbryta vs decreasing by 0.08 grams per deciliter for the placebo group.

Descreased Hemolysis

Oxbryta DECREASED hemolysis

(the breakdown of red blood cells), which IMPROVED anemia

Patients taking Oxbryta also showed large decreases in hemolysis [hi-mol-uh-sis] (the breakdown of red blood cells).

Decreases in hemolysis are good, and mean that fewer red blood cells are breaking down. Hemolysis can be measured in different ways including: bilirubin

Bilirubin is a substance made in the body when red blood cells break down. Low bilirubin levels are good because that means fewer red blood cells are breaking down, which can lead to anemia.
[bil-uh-roo-bin] levels and reticulocyte
A reticulocyte is a new or “baby” red blood cell that has not yet fully developed. When your body isn’t getting enough oxygen, the body works hard to add more red blood cells by creating reticulocytes.
 [ri-tik-uh-luh-site] count.

Decreases in hemolysis are good, and mean that fewer red blood cells are breaking down. Hemolysis can be measured in different ways including: bilirubin [bil-uh-roo-bin] levels and reticulocyte [ri-tik-uh-luh-site] count.

Bilirubin Levels

After taking Oxbryta, patients had lower bilirubin levels than before they started treatment. On average, their bilirubin levels fell by 29.08% vs only 3.16% for the placebo group.

Reticulocyte Count

On average, the reticulocyte count for patients taking Oxbryta fell by 19.93% vs the patients on placebo, whose reticulocyte count increased by 4.54%.

Tell your doctor if you have any side effect that bothers you or that does not go away.


Do not take Oxbryta

Do not take Oxbryta if you have had an allergic reaction to voxelotor or any of the ingredients in Oxbryta. See the Patient Prescribing Information for a list of the ingredients in Oxbryta.

Allergic Reactions

Oxbryta can cause serious side effects including serious allergic reactions. Tell your doctor or get emergency medical help right away if you get:

  • rash
  • hives
  • shortness of breath
  • swelling of the face
Side Effects

The most common side effects of Oxbryta included:

  • headache
  • diarrhea
  • stomach (abdominal) pain
  • nausea
  • tiredness
  • rash
  • fever

Oxbryta has been studied in people with sickle cell and was shown to be well tolerated.

These are not all the possible side effects of Oxbryta. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088. You may also report side effects to Global Blood Therapeutics, Inc. at 1-833-428-4968 (1-833-GBT-4YOU).

"I like to ride my bike and go places, so I make sure to eat well, drink lots of water, and let my body rest every day."


Actual Oxbryta patient


How Do I Take Oxbryta?

Oxbryta is a convenient oral medication (tablet).

Oxbryta tablet

Take Oxbryta once a day, exactly as your doctor tells you.

Swallow each Oxbryta tablet whole. Do not cut, crush or chew the tablets.

Changing Dose

Do not change your dose or stop taking Oxbryta unless your healthcare provider tells you to.

Your healthcare provider may change your dose if needed.

Your doctor may prescribe Oxbryta in addition to hydroxyurea.

Oxbryta can be taken with or without food.

If you forget to take a dose of Oxbryta, skip that dose and return to your normal dosing schedule the next day.

Convenient dosing fits easily into your daily routine.

Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements. Some medicines may affect how Oxbryta works. Oxbryta may also affect how other medicines work.

"I enjoy time with my family and my kids—it’s something that is truly priceless."


Actual Oxbryta patient


Talk to your doctor or other healthcare provider to see if Oxbryta could be right for you.

Download the Oxbryta Doctor Discussion Guide

Find specific questions you can ask your doctor to start a conversation about Oxbryta.

GBT Source Solutions Brochure thumbnailDOCTOR DISCUSSION GUIDE