There are currently no effective systemic therapies for metastatic adenoid cystic carcinoma (ACC), a rare cancer that forms in the salivary glands. A new study led by Renata Ferrarotto, M.D., and Luana Sousa, M.D., builds on previous findings in two major disease subtypes, including ACC-I, associated with poor patient prognosis.
By exploring the tumor microenvironment, the researchers discovered that ACC-I tumors overexpressed the immune checkpoint protein B7-H4, resulting in an immune-excluded tumor microenvironment. In ACC-I lab models, treatment with an antibody-drug conjugate targeting B7-H4 led to a 90% complete response rate, highlighting B7-H4 as a potential therapeutic target. These results suggest further investigation of B7-H4 targeting agents is merited and underscores the need to develop biomarkers for individualized treatment in this diverse patient population.