Arul Chinnaiyan, MD, PhD and Rohit Mehra, MD are contributing authors of a new paper, Comprehensive evaluation of PD-L1 expression in primary and metastatic prostate cancer, published in The American Journal of Pathology.
Immune checkpoint inhibition with antibodies that target the programmed cell death 1 (PD1) pathway and its ligand (PDL1) have demonstrated significant clinical activity by providing durable benefits with minimal toxicities in multiple solid tumors. The rapid development of PD1/PDL1 immune checkpoint inhibitors has created an urgent need for predictive biomarkers to aid in the selection of patients most likely to respond to therapy. Limited data exist on PD-L1 expression in primary clinically localized prostate cancer and metastatic castrate-resistant prostate cancer (mCRPC).
In a collaborative work led by investigators from John Hopkins University, Dr. Mehra and Dr. Chinnaiyan demonstrated positive PD-L1 expression by immunohistochemistry in <10% of clinically localized prostate cancers, about 30% of mCRPC and 40% of small cell carcinomas of the prostate. Resources from the Michigan Legacy Tissue Program (MLTP, co-directed by Dr. Mehra) at Department of Pathology and Michigan Center for Translational Pathology (MCTP) were vital for the results of this study. These findings hold promise for the future development of immunotherapy in prostate cancer.
Read the entire article online at The American Journal of Pathology.