An AE was defined as any untoward medical occurrence associated with the use of a drug in humans, whether or not considered drug related. TEAEs were defined as AEs with onset on or after the date of informed consent until 28 days after last dose of study drug. SCD-related TEAEs included preferred terms (PTs) of sickle cell anaemia with crisis, acute chest syndrome (ACS), pneumonia, priapism, and osteonecrosis. The number of participants with any SCD-related TEAEs was reported in this outcome measure.

The safety population included all enrolled participants who received treatment with study drug voxelotor in the current study.

An AE was defined as any untoward medical occurrence associated with the use of a drug in humans, whether or not considered drug related. TEAEs were defined as AEs with onset on or after the date of informed consent until 28 days after last dose of study drug. Non-SCD-related TEAEs included all the PTs of TEAEs other than SCD- related TEAEs. The number of participants with any non-SCD-related TEAEs was reported in this outcome measure.

The safety population included all enrolled participants who received treatment with study drug voxelotor in the current study.

An SAE is an AE at any dose, in view of investigator resulted in any of following outcomes: death; life-threatening AE; inpatient hospitalization/prolongation of existing hospitalization; persistent/significant incapacity or disability; a congenital anomaly/birth defect and important medical events (IME) that may not result in death, be immediately life threatening; or require hospitalization may be considered serious when based upon medical judgement, they may jeopardize study participant and may require medical or surgical intervention to prevent one of outcomes listed in definition. TESAEs were defined as SAEs with onset on or after the date of informed consent until 28 days after last dose of study drug. Number of participants with SCD-Related TESAEs was reported in this outcome measure.

The safety population included all enrolled participants who received treatment with study drug voxelotor in the current study.

An SAE is an AE at any dose, in view of investigator resulted in any of following outcomes: death; life-threatening AE; inpatient hospitalization/prolongation of existing hospitalization; persistent/significant incapacity or disability; a congenital anomaly/birth defect and IME that may not result in death, be immediately life threatening; or require hospitalization may be considered serious when based upon medical judgement, they may jeopardize study participant and may require medical or surgical intervention to prevent one of outcomes listed in definition. TESAEs were defined as SAEs with onset on or after the date of informed consent until 28 days after last dose of study drug. Number of participants with non-SCD related TESAEs was reported in this outcome measure.

The safety population included all enrolled participants who received treatment with study drug voxelotor in the current study.

Annualized incidence rate was defined as total number of events (i.e. complications observed for all participants) divided by total person years. Total person-years= sum of participant summary period in years where summary period=date of informed consent until the earlier of 28 days after last dose of study drug or end of study date. SCD related complications included acute chest syndrome, cerebrovascular accident, hepatic sequestration, ocular icterus, osteonecrosis, pneumonia, priapism, pulmonary hypertension, retinopathy, sickle cell anaemia with crisis, skin ulcer and splenic sequestration. The 95% CI was based on exact Poisson confidence limits. Incidence rate of all SCD related complications is reported in this outcome measure.

The safety population included all enrolled participants who received treatment with study drug voxelotor in the current study.

Annualized incidence rate was defined as total number of VOC events divided by total person years. Total person-years= sum of participant summary period in years where summary period=date of informed consent to last dose of study drug. VOC during the treatment period was defined as composite of acute painful crisis or acute chest syndrome (ACS) and included the following: moderate to severe pain lasting at least 2 hours; no explanation other than VOC; required oral or parenteral opioids, ketorolac, or other analgesics prescribed or directed by a healthcare professional. The 95% CI was based on exact Poisson confidence limits.

The safety population included all enrolled participants who received treatment with study drug voxelotor in the current study.

Change from baseline in hemoglobin at Week 48 was reported in this outcome measure. Baseline value was defined as the last available value (including Week 72, end of treatment [EOT], or end of study [EOS] visits in the parent study GBT440-031 [NCT03036813]) collected on or prior to first dose in GBT440-034.

The safety population included all enrolled participants who received treatment with study drug voxelotor in the current study. Here, "Overall Number of Participants Analyzed" signifies number of participants evaluable for this outcome measure and "Number Analyzed" = number of participants evaluable for specified rows.

Percent change from baseline in reticulocytes percentage at Week 48 was reported in this outcome measure. Baseline value was defined as the last available value (including Week 72, EOT, or EOS visits in the parent study GBT440-031 [NCT03036813]) collected on or prior to first dose in GBT440-034.

The safety population included all enrolled participants who received treatment with study drug voxelotor in the current study. Here, "Overall Number of Participants Analyzed" signifies number of participants evaluable for this outcome measure.

Percent change from baseline in absolute reticulocytes at Week 48 was reported in this outcome measure. Baseline value was defined as the last available value (including Week 72, EOT, or EOS visits in the parent study GBT440-031 [NCT03036813]) collected on or prior to first dose in GBT440-034.

The safety population included all enrolled participants who received treatment with study drug voxelotor in the current study. Here, "Overall Number of Participants Analyzed" signifies number of participants evaluable for this outcome measure.

Percent change from baseline in indirect bilirubin at Week 48 was reported in this outcome measure. Baseline value was defined as the last available value (including Week 72, EOT, or EOS visits in the parent study GBT440-031 [NCT03036813]) collected on or prior to first dose in GBT440-034.

The safety population included all enrolled participants who received treatment with study drug voxelotor in the current study. Here, "Overall Number of Participants Analyzed" signifies number of participants evaluable for this outcome measure.