Dr. Chatzkel highlights study of atezolizumab plus tivozanib in CRPC

In this video, Jonathan A. Chatzkel, MD, shares the background and methodology for the ongoing study, “A phase Ib/II study (IMMCO-1) of atezolizumab plus tivozanib in castrate-resistant prostate cancer and certain other immunologically cold tumors,” which was highlighted at the 2024 ASCO Genitourinary Cancers Symposium in San Francisco, California. Chatzkel is an assistant professor of medicine in the division of hematology and oncology at the University of Florida College of Medicine in Gainesville, Florida.

Video Transcript:

I'm going to be talking about our trials in progress poster [on] atezolizumab plus tivozanib for certain immunologically cold tumor types. It's a study that's being run at the University of Florida. We know that castrate-resistant prostate cancer is an immunologically cold tumor, with only a low response rate to immunotherapy. We also know that VEGF secreted by tumors can play a key role in hindering anti-tumor immune response, which can in turn lead to the development of abnormal vasculature and limited immune surveillance. VEGF may also inhibit dendritic cell differentiation, which can limit the presentation of tumor antigens. We therefore feel that the inhibition of VEGF may potentiate the effect of PD-1/L1 directed therapy by enabling immune surveillance and antigen presentation. VEGF-TKIs, as well as checkpoint inhibitor combinations are currently approved in the treatment of advanced kidney cancer, but also several other tumor types. This signal-seeking study aims to determine whether the combination of the VEGF-TKI tivozanib and the PD-L1 [inhibitor] atezolizumab can be effective in castrate-resistant prostate cancer and certain other immunologically cold tumors, including biliary tract tumors, certain neuroendocrine tumors, ovarian vulvar cancer, sarcoma, and certain patients with breast cancer.

This is a single-center phase 1b/2 basket study being carried out at the University of Florida. The phase 1b portion was completed without any dose-limiting toxicity that were identified, but a subsequent protocol amendment did decrease the starting dose of tivozanib down to a 0.89 mg/day for 21 days of each 28-day cycle. That's for that phase 2 portion that we're currently in. The co-primary end points are safety and overall response rate as measured via RESIST v1.1.

This transcription has been edited for clarity.