This study is researching 2 different experimental drugs called REGN9933 and REGN7508 (called "study drugs"). The study is focused on adults undergoing a placement of a catheter in the vein, also called a 'PICC line'. The aim of the study is to see how effective the study drug is at preventing venous thromboembolism (VTE) and other related disease after catheter placement. The study is looking at several other research questions, including: * What side effects may happen from taking the study drug * How much study drug is in the blood at different times * Whether the body makes antibodies against the study drug (which could make the study drug less effective or could lead to side effects)