[Perspectives] Subcutaneous immunotherapy—a wolf in sheep's clothing?

Over the past decade, subcutaneous formulations of anticancer drugs—originally administered intravenously—have been increasingly developed and subsequently approved by the US Food and Drug Administration (FDA). This new route of administration benefits patients with increased convenience. In this essay, we describe and discuss the growing adoption of subcutaneous formulations and also consider the potential future economic effects, particularly in relation to immunotherapy.