Background: Targeted Radioimmunotherapy (RIT) is an attractive approach to selectively
localize therapeutic radionuclides to malignant cells within primary and metastatic
tumors while sparing normal tissues from the effects of radiation. Many human malignancies
express B7-H3 on the tumor cell surface, while expression on the majority of normal tissues is
limited, presenting B7-H3 as a candidate target for RIT. This review provides an overview of
the general principles of targeted RIT and discusses publications that have used radiolabeled
B7-H3-targeted antibodies for RIT of cancer in preclinical or clinical studies.
Methods: Databases including PubMed, Scopus, and Google Scholar were searched for publications
through June 2018 using a combination of terms including “B7-H3”, “radioimmunotherapy”,
“targeted”, “radiotherapy”, and “cancer”. After screening search results for relevancy,
ten publications were included for discussion.
Results: B7-H3-targeted RIT studies to date range from antibody development and assessment
of novel Radioimmunoconjugates (RICs) in animal models of human cancer to phase
II/III trials in humans. The majority of clinical studies have used B7-H3-targeted RICs for intra-
compartment RIT of central nervous system malignancies. The results of these studies
have indicated high tolerability and favorable efficacy outcomes, supporting further assessment
of B7-H3-targeted RIT in larger trials. Preclinical B7-H3-targeted RIT studies have also
shown encouraging therapeutic outcomes in a variety of solid malignancies.
Conclusion: B7-H3-targeted RIT studies over the last 15 years have demonstrated feasibility
for clinical development and support future assessment in a broader array of human malignancies.
Future directions worthy of exploration include strategies that combine B7-H3-
targeted RIT with chemotherapy or immunotherapy.