This clinical research trial will evaluate the safety and tolerability of an experimental drug, ALN-F1202, in healthy participants. The purpose of this trial is to learn about how safe and tolerable the experimental drug is. The trial is looking at several other research questions, including: * What side effects may happen from taking the experimental drug? * How much experimental drug is in the blood at different times? * Whether the body makes antibodies against the experimental drug (which could make the drug less effective or could lead to side effects). * What is the best dose of the experimental drug?