Characterization of Exceptional Responses in Patients With Metastatic Castration-Resistant Prostate Cancer Treated With Cabozantinib and Immune Checkpoint Inhibitors

• Immune checkpoint inhibitors (ICIs) have been shown to have limited efficacy in unselected populations of patients with metastatic castration-resistant prostate cancer (mCRPC). In the phase III clinical trial CONTACT-02, a novel regimen combining cabozantinib and ICI improved progression-free survival in patients with mCRPC; however, due to its lack of survival benefit, it has not yet gained regulatory approval. In this retrospective series of patients with mCRPC without high tumor mutational burden or microsatellite instability treated with cabozantinib and ICI, the data indicate that a subpopulation exists with an exceptional long-term response, including some patients maintained on therapy for more than 30 months. The study further characterizes this subpopulation and can guide treatment selections for patients with limited options as oncologists and regulatory bodies continue to evaluate the risks and benefits of widespread adoption of this regimen.