Adenosine Signaling Modulation and Immune Checkpoint Inhibition With Hormone Sensitive Oligometastatic Prostate Cancer

The optimal therapeutic approach to men with oligometastatic (1-3 or 1-5 sites of metastatic disease) prostate cancer is ever more important as advanced imaging technologies are becoming standard of care, providing clinicians with the tools to accurately diagnose and localize oligometastatic prostate cancer. Hence, methods to improve the local curative potential of stereotactic body radiation therapy (SBRT) is a timely and important opportunity. In addition, previous data suggest that the adenosine A2A pathway may be a particularly attractive avenue for intervention in the context of radiation, thus influencing multiple suppressive populations within the tumor microenvironment (TME). Immunotherapy based on the PD-1/PD-L1 signaling axis is a mainstay of therapy across multiple types of malignancies. This study aims to evaluate the effectiveness of a PD-1 inhibitor (zimberelimab) in combination with a selective dual antagonist of A2aR and A2bR (etrumadenant) and an anti-CD73 (quemliclustat). Immune checkpoint inhibitors and targeted inhibitors of the adenosine signaling axis modulate the TME and aspects of the systemic immune system to overcome tumor-induced immune suppression and improve responses to therapy. This study aims to determine the effect of etrumadenant, quemliclustat and zimberelimab \[experimental\] when given with ablative radiation (SBRT)\[standard of care\] on the oligoprogressive disease (hormone sensitive oligometastatic prostate cancer), defined by being free from radiographic progression of irradiated target metastases and PSA (prostate surface antigen) response at 6 months. PSA response, local control, progression-free survival (PFS), treatment response, ADT-free survival, time-to-pain, and safety and tolerability will also be measured. By employing a Simon Two-Stage design, the trial will test whether or not etrumadenant + quemliclustat and zimberelimab combined with ablative radiation (SBRT) will improve PFS compared to SBRT alone (ORIOLE).