The objective of this Expanded Access Protocol (EAP) is to provide voxelotor for the treatment of sickle cell disease (SCD): The study GBT440-041 is the EAP for pediatric patients aged 6 months to 11 years who have no alternative treatment options and are ineligible to participate in a clinical trial of voxelotor and the study C5341057 is the EAP for adults/adolescents 12 years of age and older for patients who cannot satisfactorily be treated with an authorized medicinal product

This EAP may continue until such time that voxelotor is commercially available or the Sponsor discontinues the voxelotor EAP.

Please note that for US sites, enrollment is open only for 6months to < 4 years of age.

Inclusion Criteria: GBT440-041

1. Documented diagnosis of sickle cell disease of any genotype
2. Ineligible or unable to participate in actively recruiting clinical studies of voxelotor
3. Baseline hemoglobin (Hb) ≤10.5 g/dL
4. No alternative treatment options in the judgement of the treating Investigator
5. Participants who, if female of childbearing potential (post-menarche), and are sexually active, agree to use highly effective methods of contraception from study start to 30 days after the last dose of voxelotor
6. Written informed parental/guardian consent and participant assent (if applicable) has been obtained per Institutional Review Board (IRB) policy and requirements, consistent with International Council for Harmonisation (ICH) guidelines

Exclusion Criteria: GBT440-041

1. Receiving chronic red blood cell (RBC) transfusion therapy for primary or secondary stroke prevention

2. Hepatic dysfunction characterized by alanine aminotransferase (ALT) >4 × the upper limit of normal (ULN) for age

3. Severe renal dysfunction (estimated glomerular filtration rate [eGFR] <30 mL/min/1.73 m2 by Schwartz formula)

4. Clinically significant bacterial, fungal, parasitic, or viral infection that requires therapy:

   1. Patients with acute bacterial infection requiring antibiotic use should delay screening/enrollment until the course of antibiotic therapy has been completed.
   2. Patients with known active hepatitis A, B, or C or who are known to be Human Immunodeficiency Virus (HIV) positive

5. Any condition affecting drug absorption, such as major surgery involving the stomach or small intestine (prior cholecystectomy is acceptable)

6. Female who is pregnant or breastfeeding

7. Participated in another clinical trial of an investigational drug or medical device, within 30 days or 5 half-lives of the investigational drug (whichever is longer) prior to informed consent for the EAP, or is currently participating in another trial of an investigational drug or medical device

8. Medical, psychological, or behavioral conditions, that, in the opinion of the Investigator, may preclude informed consent, safe participation, or compliance with the protocol procedures

9. Use of herbal medications (eg, St. John's wort), sensitive cytochrome P450 (CYP) 3A4 substrates with a narrow therapeutic index, or strong CYP3A4 inducers

10. Active symptomatic COVID-19 infection

Inclusion Criteria: C5341057

1. Documented diagnosis of SCD of any genotype confirmed by laboratory genetic testing
2. Aged 12 years and older
3. Haemoglobin ≥5.5 and ≤ 10.5 g/dL, based on a test performed according to local standard of care
4. Patient cannot be treated satisfactorily with any authorised medicinal product
5. Patient or their legal representative has provided written informed consent to participate in the voxelotor EAP for the treatment of SCD
6. Patient or their legal representative has provided written informed consent on data processing and protection

Exclusion Criteria: C5341057

1. Patients with clinically significant bacterial, fungal, parasitic or viral infection which requires therapy.
2. History of serious drug hypersensitivity reaction to voxelotor or excipients
3. Participated in another clinical trial of an investigational agent (or medical device) within 30 days of participation in EAP.
4. 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