This is a Phase 1, Randomized, Single-blind, Placebo-controlled Study to Assess the Safety, Pharmacokinetics (PK), and Pharmacodynamics (PD) of BEAM-103 in Healthy Subjects

The purpose of this Phase I single ascending dose study is to evaluate the safety, pharmacokinetics (PK), and pharmacodynamics (PD) of BEAM-103 in healthy subjects between the ages of 18 and 55. The main questions the study aims to answer are: * Safety and tolerability of BEAM-103 * The pharmacokinetic (PK) profile and pharmacodynamic (PD) characteristics of EAM-103 * The effect of BEAM-103 on hematologic parameters * To assess the immunogenicity of BEAM-103 Researchers will determine and establish the therapeutic window of the antibody and select optimal doses for future trials in patients. Subjects will: * Be asked to participate in the study for a duration of 4-5 months total * Be asked to sign informed consent * Be assessed for eligibility * Provide medical and medication history * Receive a single intravenous infusion of BEAM-103 or placebo on study Day 1 according to their assigned cohort * Be followed up to 4 months after infusion