Biocept and Dr. Shilpa Gupta, an expert in cancers of the genitourinary tract, are working together to develop liquid, or blood-based, biopsies for patients with bladder and prostate cancer that may help improve the diagnosis and treatment of those cancers.
Dr. Gupta, an assistant professor in the Division of Hematology, Oncology and Transplantation at Masonic Cancer Center, University of Minnesota, has served as the principal investigator in a number of clinical trials into bladder and prostate cancer.
“We are delighted to be working with Dr. Gupta, a leading expert in the field of genitourinary cancers, including bladder and prostate cancers and the role of targeted therapies and immunotherapy agents in these disease states,” Veena Singh, MD, Biocept’s senior vice president and senior medical director, said in a press release. “Dr. Gupta has been an active speaker at national and international forums discussing the role of novel therapeutics for personalized medicine in prostate cancer.”
The proposed study will assess the utility of Biocept’s patented Target Selector liquid biopsy technology platform in detecting the expression of PD-L1 and androgen receptor (AR) in circulating tumor cells (CTCs).
CTCs are cells that detach from the primary tumor and enter the bloodstream. In some cases, these cells can be tested to understand a tumor’s general behavior, including changes in gene expression and tumor-acquired mutations that can be involved in resistance to treatment. How the expression of PD-L1 and AR in CTCs of bladder and prostate cancer correlate with response to therapies, however, is not fully understood.
“PD-L1 is expressed in multiple cancer types and several therapies that target PD-1/PD-L1 are approved and being studied in a variety of tumors,” said Gupta. “However, the utility of PD-L1 in CTCs in bladder cancer and correlation with response to anti-PD1 therapies is unknown, and we propose to study the expression of PD-L1 in patients with bladder cancer at diagnosis and while on anti-PD-1/PD-L1 therapies.
“AR is a known therapeutic target in prostate cancer, but the utility of looking at AR expression in CTCs of patients with prostate cancer while on AR-directed therapies is unknown,” he added.
Gupta and colleagues are now exploring the anti-androgen drug Xtandi (enzalutamide) in combination with chemotherapy in a clinical trial (NCT02300610) in advanced bladder cancers, which is currently recruiting patients.
Usually, tissue biopsies are collected from patients with advanced prostate and bladder cancers to inform physicians about a patient’s disease and therapeutic options, “but these methods are invasive and can be expensive,” Gupta said.
“Biocept’s liquid biopsy tests have shown high concordance with tissue biopsies in detecting genetic mutations associated with multiple cancers, and this study is aimed at providing additional information for the use of these tests specifically in bladder and prostate cancers to help in clinical decision making,” he added.