Loqtorzi (toripalimab-tpzi) is a programmed death receptor-1 (PD-1) blocking antibody that works by binding to the PD-1 receptor that exists on the outside of some cancer cells. PD-1 prevents our immune system from attacking the cancerous cells, but once Loqtorzi has bound to PD-1, the immune system is no longer inhibited, and immune system components, such as T cells, can kill the cell.