A Study to Learn About Sickle Cell Disease In Adult Patients

The purpose of this clinical trial is to evaluate the performance of the sickle cell disease (SCD) electronic diary in people with SCD who are on treatment that will change SCD and those not on such a treatment.

SCD is a type of condition when there are fewer red blood cells to carry oxygen around the body.

This disease can be passed on from parent to child and may cause pain, infections and damage to organs.

This study is seeking participants who:

* are confirmed with SCD
* are on a stable regimen of disease changing treatment or have not received any disease changing treatment before the start of the study and do not plan any changes in their treatment during the 6-month study observation period For 6 months, participants will be asked to complete a daily electronic diary to report on their experience in the past 24 hours with sickle cell pain crisis (if they got any treatment and what medications they took), worst pain, worst tiredness, and their ability to perform usual physical activities. We will compare the experiences of people who are taking SCD-modifying therapy to those that are not taking a SCD-modifying therapy.


Eligibility Criteria:
Inclusion Criteria (All Groups):

- Confirmed diagnosis of stable SCD (HbS/S or HbS/beta-zero-thalassemia).

Additional Inclusion Criteria (No Disease Modifying Treatment Control Group):

* Have experienced ≥1 episode(s) of medical utilization (MU) VOC within 12 months prior to Screening.
* Data available for number of MU VOC(s) during the 12-month interval prior to Screening and a value for %fetal hemoglobin (HbF) collected subsequent to 1 year of age in the absence of recent transfusion.

Additional Inclusion Criteria (SCD Disease Modifying Treatment Group):

* Have experienced ≥1 episode(s) of MU VOC within 12 months prior to initiation of HU and/or crizanlizumab (whichever was initiated earlier).
* Must be on a stable dose of their SCD treatment regimen ≥8 weeks prior to Day 1 with the intent of remaining on the same dose throughout the study, unless adjustments are medically necessary due to bone marrow suppression, in accordance with published guidelines and/or product specific guidance (eg, package label). Accepted SCD disease modifying treatment regimens include:

  * HU alone and/or in combination with crizanlizumab, L-glutamine and/or voxelotor; or
  * Crizanlizumab alone and/or in combination with HU, L-glutamine and/or voxelotor.
* Data available for number of MU VOC(s) during the 12-month interval prior to initiation of any SCD disease modifying treatment, as described above, and a value for %HbF collected subsequent to 1 year of age, prior to initiation of any HU treatment, and in the absence of recent transfusion.

Exclusion Criteria (All Groups):

* Evidence or history of ongoing (condition or sequelae) clinically significant hematological (non-SCD), renal, endocrine, pulmonary, gastrointestinal, cardiovascular (including overt stroke but excluding silent cerebral infarct), hepatic (excluding cholelithiasis), psychiatric or neurological disease as assessed from medical records.
* Marked ongoing bone marrow suppression as evidenced by any of the following as per medical record: severe anemia, absolute neutrophil count (ANC) \<1000 mm3 white blood cell (WBC), thrombocytopenia (platelet count \<100,000 mm3) within ≤8 weeks prior to Day 1 enrollment.
* History of hematopoietic stem cell transplant or treatment with gene therapy as assessed from medical records.
* History of simple transfusion within ≤4 weeks prior to Day 1 enrollment as assessed from medical records or participant self-report.
* History of chronic transfusion/exchange transfusion within ≤12 weeks prior to Day 1 enrollment as assessed from medical records or participant self-report and/or plan to initiate such treatment during the 6-month observation period.

Additional Exclusion Criteria (No Disease Modifying Treatment Control Group):

* Participant received HU and/or crizanlizumab at any time within ≤18 months of Day 1 enrollment and treatment(s) was discontinued due to lack of efficacy (no reduction in the frequency of VOCs, documented or perceived) and/or plan to initiate said treatment(s) during the 6-month observation period.
* Participant received voxelotor or L-glutamine within ≤4 weeks of Day 1 enrollment and/or plan to initiate said treatment(s) during the 6-month observation period.