This study is looking at the effects of a drug called **Oxbryta** on people with **Sickle Cell Disease (SCD)**. SCD is a condition where red blood cells become a sickle, or crescent, shape, which can cause pain and other health problems. The study will happen at about 45 places in the United States. It's an **observational study**, meaning the researchers will watch what happens when people take Oxbryta as part of their regular care, but won't change or control their treatment. Anyone taking Oxbryta or planning to start can join. Participants will be in the study for up to 5 years, or until they choose to leave.

• The study lasts up to 5 years, but you can leave anytime.
• Participants will continue their usual care and treatment with Oxbryta.
• Data from medical records will be collected, with no extra treatments required.