The purpose of this study is to learn about how long novel hormonal therapies are taken by men to treat mCSPC. Novel hormonal therapies in this study include study medicines abiraterone, apalutamide, and enzalutamide.

Prostate cancer is one of the most common cancers in men. The prostate is a gland in the male body that helps make semen. Metastatic cancer is a cancer that has spread to other parts of the body. Castration-sensitive prostate cancer means the cancer is being controlled by keeping the testosterone levels as low as would be expected if the testicles were removed by surgery.

This is a real-world study, not a clinical trial. This means that researchers will look at what happens when men receive the treatments prescribed by their own doctor as part of their usual healthcare treatment. In this study, researchers will use insurance claim information from Medicare claims data.

The study will include patients' information from the database for men who:

• Were identified to have mCSPC.
• Started treatment with novel hormonal therapy (index date) for mCSPC.
• Were 65 years of age or older one year before index date.

Men in this study will be taking novel hormonal therapy for treatment of their mCSPC. We will describe how long men take novel hormonal therapy. This study will use patient information from insurance claims. It will take information one year before start of novel hormonal treatment until the end of insurance period or until information is available.

Inclusion Criteria:

• Male with ≥ 1 diagnosis claim for prostate cancer
• Have documented secondary metastasis code on or after the initial prostate cancer diagnosis
• Have initiated novel hormonal therapy (abiraterone, apalutamide, or enzalutamide) within 30 days prior to the metastasis date or on or after the metastasis date. The initiation date of the earliest novel hormonal therapy will be defined as the index date.
• Have a claim for androgen deprivation therapy (ADT) within 90 days prior to or within 30 days after the index date
• ≥65 years old 12 months prior to the index date
• Continuous enrollment in Medicare Parts A, B, and D for ≥12 months prior to the index date and ≥6 months following the index date (unless death)

Exclusion Criteria:

• Claims indicating ≥8 weeks of continuous ADT use between 90 and 365 days prior to the index date, which may indicate castration-resistance
• Received chemotherapy, novel hormonal therapy, radium-223, PARP inhibitor, immunotherapy, or surgical castration prior to the index date
• Had a prior history of other cancers

Men with metastatic castration-sensitive prostate cancer who initiated novel hormonal therapy (abiraterone, apalutamide, or enzalutamide) and met eligibility criteria will be included in the study. Patients will be identified from the 100% Fee-For-Service Medicare claims data.

Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical\_trials/trial\_data\_and\_results/data\_requests.

Analysis population included all eligible participants who met inclusion/exclusion criteria, whose data was retrieved and observed in the study.

Not applicable as adverse events and all-cause mortality were not planned to be evaluated for the study

Due to non-interventional nature of study, the minimum criteria for reporting an adverse event (i.e., identifiable participant, identifiable reporter, a suspect product, and event) could not be met. Hence, adverse events were not planned to be evaluated (thus at risk appears "0").