1796P Real-world Analysis of Metastatic Hormone-Sensitive Prostate Cancer: Are Randomized Clinical Trials More Trustworthy? Insights from PIONEER, the European Network of Excellence for Big Data in Prostate Cancer

Androgen deprivation therapy (ADT) was the standard of care (SOC) for patients with metastatic Hormone Sensitive Prostate Cancer (mHSPC); recently, emerging therapies associated with ADT have proven to be more effective than ADT alone, however there is an unmet need of standardization of randomized control trials (RCTs) comparing the various combinations of available drugs. Real Word Data (RWD) may be used to identify relevant outcomes with unmet clinical needs with a greater likelihood of benefiting from new therapies. We aim to describe demographics, clinical characteristics, treatment patterns and clinical outcomes of a large multicenter cohort of patients with mHSPC in RWD under the PIONEER project. Data of patients with mHSPC across a distributed network of observational databases were collected. Male patients without prior orchiectomy with mHSPC were enrolled in Cohort 1, while Cohort 2 was defined as the start of ADT as a surrogate definition of mHSPC disease, both in metachronous and synchronous disease settings. Overall, 94,261 mHSPC patients were included among which 77,123 patients received treatment. 28% of mHSPC diagnosed were not on ADT monotherapy. More than half of the patients were over 70 years old (54%), older than the average age on the available RCT. In cohort 2, 2,819 patients were metachronous and 55,502 patients were synchronous. Most of the patients are treated with ADT only; after a Median follow-up (ranged from 398-699 days) in the metachronous setting 22% of them discontinued the treatment. Regarding the clinical outcomes, time to admission to hospital or emergency Department, adverse events and death increase with time, but noticeably events are more common in synchronous disease. This is the largest study in Europe with RWD in the mHSPC setting. Landscape of prostate cancer treatment is constantly evolving, so it is important to understand the behavior of the disease in real-world setting, so we are able to fill gaps or create new questions to create evidence. In RWD that patients are older, with more co-mobilities and 1/3 of them do not undergo a SCO treatment when compared to RCT.