Clinical Validation of a Circulating Tumor Cell AR Therapy Resistance Assay in Men With Metastatic Castration Resistant Prostate Cancer (ARCTIC)
This study will follow men with metastatic castration resistant prostate cancer throughout their standard of care treatment for their disease to determine if the presence of different genes or proteins can predict which patients respond to the cancer treatment they receive. As tumors grow and begin to spread, they may release cells into patients' bloodstream. These cells are called circulating tumor cells, or CTCs. CTCs can be used to look for differences in biomarkers (genes or proteins that may change based on how a person is or is not responding to treatment). The purpose of this research study is to learn whether scientists can use biomarkers from CTCs to predict which tumors will respond to certain hormonal therapies. Participants will have blood collected and provide an archival sample from a previous tumor biopsy. The researchers will compare biomarkers from participants who responded well to treatment to those who responded poorly in order to answer the research question.
∙ Patients will be eligible for inclusion in this study only if all of the following criteria apply:
• Histologically confirmed diagnosis of adenocarcinoma of the prostate. Patients with pure small cell/neuroendocrine tumors of the prostate are not permitted.
• Radiographic evidence of metastatic disease by CT, MRI, or PET imaging.
• Prior documented disease progression on one potent AR inhibitor (darolutamide, abiraterone, enzalutamide, or apalutamide or combinations of these) in any disease setting (mHSPC, nmCRPC, mCRPC) based on sequential PSA rises or radiographic progression.
• Planned therapy with either standard of care enzalutamide and/or abiraterone acetate or another potent AR inhibitor (darolutamide, apalutamide if available) within the coming 6 weeks
• Castrate levels of testosterone (\<50 ng/dl) at most recent assessment and/or documented ongoing Androgen Deprivation Therapy.
• Evidence of disease progression based on a rising PSA on or following most recent therapy as evidenced by the following:
‣ Consecutive PSA rises at least 2 weeks apart
⁃ Minimum PSA of 1.0 ng/dl prior to entry
• Age \> 18 years.
• Ability to understand and the willingness to sign a written informed consent document.