Safety of Anumigilimab (CSL324) in Adults With Sickle Cell Disease (SCD)

This is a phase 2a, global, multicenter, randomized, double-blind, placebo-controlled study investigating the safety of anumigilimab administered subcutaneously (SC) at the maximum tolerated dose (MTD) in adult participants with SCD. The primary aim of the study is to assess the safety of anumigilimab in participants with SCD. Participants will be treated for 64 weeks: for 12 weeks in the dose escalation period, where the dose will be escalated to each participant's individual MTD; and for 52 weeks at the MTD in the maintenance period.

Inclusion Criteria: * Adults aged greater than or equal to (\>=) 18 years on the day of signing the informed consent form. * Confirmed diagnosis of SCD of any genotype. * Experienced 1 to 12 VOCs requiring a visit to a medical facility and treatment with parenteral opioids or a parenteral nonsteroidal anti-inflammatory drug within the 12 months before Screening. * HU Regimen: * a. On stable and well-tolerated Hydroxyurea (HU) regimen for at least 30 days before Screening. * or * b. HU was discontinued or refused (eg, due to concern of side effects or lack of effect). Exclusion Criteria: * Absolute neutrophil count less than (\