Optimizing Abiraterone Therapy

Optimizing Abiraterone (Zytiga®) Therapy by Exploring the Relation Between an Early Biomarker - Drug Exposure - as a Predictor for Drug Response in Patients With mCRPC

The purpose of this study is to explore whether early abiraterone exposure is related to treatment response in patients with metastatic castration resistant prostate cancer. Furthermore to explore the relation between biomarkers and treatment response and drug exposure.

Inclusion Criteria:

• Patients with metastatic castration resistant prostate cancer who are asymptomatic or mildly symptomatic after failure of androgen deprivation therapy in whom chemotherapy is not yet clinically indicated
• Age ≥18 years
• Feasible to collect blood samples from
• Life expectancy of > 6 months
• Measurable disease
• Able and willing to give written informed consent prior to screening and enrollment

Exclusion Criteria:

• other anticancer therapies
• potent CYP3A4 inducers
• herbal medicine that could interfere with abiraterone exposure