Safety, Tolerability, Pharmacokinetic, and Pharmacodynamic Study of ALXN2230 in Healthy Participants

Inclusion Criteria: * Participants who are overtly healthy as determined by medical evaluation including medical history, physical examination, laboratory tests, and cardiac monitoring. * Baseline immunoglobulin G (IgG) concentrations ≥ 1000 milligrams per deciliter (mg/dL) and ≤ 1600 mg/dL at Screening. * Antibody titers for Tetanus toxoid (≥ 0.1 International Units per milliliter (IU/mL)) at Screening. * Nonsmokers and not using any nicotine-containing products. A nonsmoker is defined as an individual who has abstained from smoking for at least 1 year prior to Screening. * BMI within the range 18 to 32 kilograms per square meter (kg/m2), inclusive; with body weight ≥ 50 kilograms (kg). Exclusion Criteria: * History or presence of cardiovascular, respiratory, hepatic, renal, gastrointestinal, endocrinological, hematological, or neurological disorders capable of significantly altering the absorption, metabolism, or elimination of drugs; constituting a risk when taking the study intervention; or interfering with the interpretation of data. * Abnormal blood pressure (BP) (resting BP not to exceed 140/80 mmHg and no less than 90/60 mmHg). * Participants who have history of allergy or hypersensitivity to excipients in ALXN2230. * History of unexplained, recurrent infection, or infection requiring treatment with systemic antibiotics within 90 days prior to dosing on Day 1. * Pregnant or breastfeeding females are excluded from the clinical study. * Participants with known clinically relevant immunological disorders. * Lymphoma, leukemia, breast cancer or any malignancy within the past 5 years except for basal cell or squamous epithelial carcinomas of the skin that have been resected with no evidence of metastatic disease for 5 years. * ALT \> 1.0 × upper limit of normal (ULN) * TBIL \> 1.0 × ULN * Current or chronic history of liver disease or known hepatic or biliary abnormalities (with exception for Gilbert's syndrome). * QTc \> 450 millisecond (msec) for male participants or \> 470 msec for female participants. * Significant blood loss (including blood donation \[\> 500 mL\]) or had a transfusion of any blood product within 12 weeks prior to dosing or plan 1 within 4 weeks after the end of the study. Additional inclusion/exclusion criteria may apply, per protocol.