Phase 2 trial of neoadjuvant enoblituzumab for localized prostate cancer

B7 homolog 3 (B7-H3; CD276), a tumor-associated antigen and possible immune checkpoint, is highly expressed in prostate cancer (PCa), and is associated with early recurrence and metastasis. Enoblituzumab is a humanized B7-H3 targeting antibody that mediates antibody-dependent cellular toxicity. A phase 2 trial at Johns Hopkins School of Medicine (Baltimore, MD) evaluated neoadjuvant enoblituzumab for localized PCa. There were no notable unexpected surgical or medical complications, and there was no surgical delay. Grade 3 adverse events were seen in 12% of patients; there were no grade 4 or 5 AEs. One year after prostatectomy, there was no detectable PSA level in 66% of patients (95% CI 47-81). The authors conclude that the use of B7-H3-targeted immunotherapy in PCa is feasible and generally safe, and preliminary data suggest potential clinical activity.