The main routes of administration of anticancer drugs vary depending on the nature of the drug used, such as oral administration, intravenous injection, and intravenous drip. Antibody drugs are composed of amino acids and are subject to degradation by digestive enzymes, making it difficult for orally administered drugs to reach the target tumor. Therefore, for systemic exposure, intravenous administration that can be directly introduced into the systemic circulation, or subcutaneous administration where high molecular absorption is possible, is performed.