Treatment of B7-H4-expressing syngeneic tumors with SGN-B7H4V led to immunomodulatory changes in the TME, including recruitment of multiple immune cell types and upregulation of immune-related genes that have been previously associated with response to anti-PD(L)1 agents. Moreover, SGN-B7H4V drove robust antitumor activity as well as durable immune memory as a monotherapy and in combination with an anti-PD1 agent... In preclinical models, SGN-B7H4V demonstrates robust antitumor activity accompanied by immunomodulatory changes in the TME. Moreover, SGN-B7H4V in combination with an anti-PD1 agent led to improved antitumor activity and elicited durable immune memory.