Real-life Experience in Brazil in Patients With Castration-resistant Prostate Cancer Treated With Olaparib+Abiraterone Observational Study Assessing Real World Clinical Endpoints and Demographic Characteristics in Patients With Castration-resistant Prostate Cancer Treated With Olaparib+Abiraterone

PROCeed is an observational, longitudinal study with prospective data from Brazilian participating sites, so as to generate real-world data. 10 Brazilian oncology sites are estimated to participate in the study. Each site will have participating investigators in charge and a proper technical team who will be in charge of data from each service. For this study, a convenience sample will be adopted, with an expected 2-year recruitment of 80 patients. The protocol was created in Germany and other countries could use it, with the potential for data from other countries to be pooled for analysis.

Recruitment to each subgroup will be monitored every 3 months and feasibility for continued enrolment will be assessed after 1 year of recruitment (at months 3 and 6, recruitment will be evaluated for proper site selection); if <20 patients have only been enrolled in a particular subgroup after 1 year, the study team will assess feasibility of pooling data from other countries to allow for at least 40 patients in a pooled analysis for that subgroup.

The study plans to recruit patients for no more than 2 years and to follow patients from the start of olaparib to 1 year after last patient inclusion (LPI). Data will be collected from the medical record through an electronic case report form (eCRF). Participating physicians will be responsible for ensuring that all necessary data are collected and entered in the eCRF. Data compilation will be performed by the principal investigator and statistical analysis will be performed by the statistics team appointed by the Academic Research Organization (ARO).

The target sample size of 80 patients in Brazil is based in a 24-month recruitment period. In order to avoid unnecessary imprecision for the subgroup previously exposed to a new hormonal agent, a minimum enrolment of 50% (40 patients) of the total sample size will be imposed for this subgroup. Estimation is determined based on the primary objective of the TTD event-free rate; the main measure of interest is at 6 months for patients previously exposed to NHA and 12 months for patients naïve to NHA. Assuming a 6- month TTD event-free rate is of approximately 50% for patients previously exposed to new hormonal agent, with a sample size of 40 patients in this subgroup, the precision would be +/- 15,5%.