This challenge will attempt to improve the prediction of survival and toxicity of docetaxel treatment in patients with metastatic castration-resistant prostate cancer (mCRPC). The primary benefit of this Challenge will be to establish new quantitative benchmarks for prognostic modeling in mCRPC, with a potential impact for clinical decision making and ultimately understanding the mechanism of disease progression. Participating teams will be asked to submit predictive models based on clinical variables from the comparator arms of four phase III clinical trials with over 2,000 mCRPC patients treated with first-line docetaxel. The comparator arm of a clinical trial represents the patients that receive a treatment that is considered to be effective. This arm of the clinical trial is used to evaluate the effectiveness of the new therapy being tested.