Inclusion Criteria:  Male and female patients with clinical diagnosis of SCD (based on laboratory parameters) of any genotype. Patients newly initiated on treatment with locally approved crizanlizumab. Patients aged 16 years or older at crizanlizumab initiation.  Exclusion Criteria:  Patients who did not provide informed consent. Patients who received a stem cell transplant at time of enrollment. Patients who participated in or are participating in a clinical trial at time of enrollment or in the 12 months prior to starting commercial crizanlizumab. According to the investigator's opinion, the patient is an unlikely candidate to provide an accurate medical history and/or to obtain long-term follow-up information for any reasons such as unavailability or severe concomitant illnesses.