Dr. Agarwal on Developing Biomarkers of Response to Cabozantinib/Atezolizumab in mCRPC

Neeraj Agarwal, MD, associate professor of medicine, University of Utah School of Medicine; and director, Genitourinary Oncology Program, Oncology Division, co-leader, Urologic Oncology Multidisciplinary Program, and associate director of Clinical Trials, Huntsman Cancer Institute, discusses the importance of developing biomarkers of response to the combination of cabozantinib (Cabometyx) and atezolizumab (Tecentriq) in patients with metastatic castration-resistant prostate cancer (mCRPC).

Understanding which patients are likely to respond to treatment and which are unlikely to respond is an ongoing challenge throughout the oncology space, says Agarwal.

The multinational phase Ib COSMIC-021 trial is evaluating the combination of cabozantinib and atezolizumab in advanced solid tumors.

In cohort 6 of the trial, the objective response rate was 32% among all 44 mCRPC cases and 33% among 36 patients with high-risk clinical features. Additionally, 80% of men treated with the combination experienced disease control.

In the larger trial, 3 additional cohorts will look at cabozantinib and atezolizumab as single agents as well as in combination, says Agarwal. Patients who progress on cabozantinib alone will cross over to receive the combination therapy.

Looking at tissue and blood samples that will be collected at the time of progression may shed light on potential biomarkers of response to the combination in this patient population, concludes Agarwal.