Vaso oclusive crisis (VOC) is defined as a pain crisis (acute onset of pain for which there is no other medically determined explanation other than vaso-occlusion) lasting for at least 4 hours which is treated as per local guidelines with standard of care therapy used to treat VOC. Acute chest syndrome (ACS), priapism and hepatic or splenic sequestration will be considered VOC in this study. VOCs included are those HCP-managed in a healthcare facility and HCP-managed via remote consultation. Annualized rate of VOC events = (Number of VOC events \* 365)/(number of days in the observation period). Observation period = time from date of randomization to minimum of (last dose date until treatment discontinuation + 27 days, date of initiation or discontinuation of HU/HC or L-Glutamine (or other therapies such as Voxelotor and erythropoietin therapies to treat SCD and/or to prevent/reduce VOCs), date of randomization + 365 days).

VOC is defined as pain crisis (defined as an acute onset of pain for which there is no other medically determined explanation other than vaso-occlusion) which requires therapy with oral or parenteral opioids or parenteral NSAID as well as other complicated crisis such as acute chest syndrome (ACS), priapism and hepatic or splenic sequestration. Healthcare visit is defined as any visit to a medical facility such as emergency room (ER), hospital and/or office visit, which includes pain management of VOC in situ. Annualized rate of corresponding VOC events = (Number of corresponding VOC events \* 365)/(number of days in the observation period). Observation period = time from date of randomization to minimum of (last dose date until treatment discontinuation + 27 days, date of initiation or discontinuation of HU/HC or L-Glutamine (or other therapies such as Voxelotor and erythropoietin therapies to treat SCD and/or to prevent/reduce VOCs), date of randomization + 365 days).

Level of soluble P-selectin in ng/mL.

A priapic event was defined as an unwanted or painful penile erection lasting at least 60 minutes. Priapic events were self-reported via an electronic reporting system, and data was collected throughout the study period. Number of priapic events was summarized at Baseline (adjusted for 26 weeks) and by 26 weeks, and percent reduction from adjusted Baseline by 26 weeks was summarized.

The area under the curve (AUC) from time zero to the last measurable concentration sampling time (tlast) (mass x time x volume-1) following the first dose. AUCd15 was calculated based on serum concentrations of crizanlizumab.

The AUC calculated to the end of a dosing interval (tau) at steady-state (amount x time x volume-1).

The maximum (peak) observed, serum, drug concentration after single or multiple dose administration (mass x volume-1)

The AUC from time zero to the last measurable concentration sampling time (tlast) (mass x time x volume-1) following the first dose. AUCd15 was calculated based on P-selectin inhibition curves.

The AUC of %inhibition calculated to the end of a dosing interval (tau) after multiple dose. AUCtau was calculated based on P-selectin inhibition curves.

An adverse event (AE) is any untoward medical occurrence (e.g. any unfavorable and unintended sign \[including abnormal laboratory findings\], symptom or disease) in a subject or clinical investigation subject

To characterize PK of crizanlizumab at 5.0 mg/kg in SCD patients. AUCd15: The AUC from time zero to the last measurable concentration sampling time (tlast) (mass x time x volume-1) after single dose AUCtau: The AUC calculated to the end of a dosing interval (tau) at steady-state (amount x time x volume-1)

To characterize PK of crizanlizumab at 5.0 mg/kg in SCD patients. Cmax: The maximum (peak) observed serum drug concentration after dose administration (mass x volume-1).

To characterize PK of crizanlizumab at 5.0 mg/kg in SCD patients, by serum concentrations by treatment group. Data was collected prior to each study drug dose; From Week 3 (loading dose), pre-dose (trough) concentrations were obtained every 4 weeks.

PD-AUCd15 and PD-AUCd29 were derived from the P-selectin inhibition data of week 1 and week 15, respectively. To characterize PD of crizanlizumab at 5.0 mg/kg in SCD patients The area under the curve (AUC) of percentage of P-selectin inhibition versus time profile after the starting dose (PD-AUCd15) and after multiple doses (PD-AUCd29) is being reported.

To characterize the PD effect of crizanlizumab in terms of Percentage of P-selectin inhibition prior to study drug dose at 5 mg/kg in CSD patients.