A Study to Learn About Two Medicines (Apalutamide and Enzalutamide) in People With Metastatic Castration-sensitive Prostate Cancer (mCSPC)

The purpose of this study is to learn about how long apalutamide and enzalutamide are taken by men to treat mCSPC.

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 study. 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 information from cancer clinics (Flatiron Health electronic health records).

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

* Were identified to have mCSPC. * Started treatment with apalutamide or enzalutamide (index date) for mCSPC. * Were 18 years of age or older on the index date. Men in this study will be taking apalutamide or enzalutamide for treatment of their mCSPC. The study will compare how long men take apalutamide or enzalutamide. This study will use patient information from cancer clinics. Information from start of apalutamide or enzalutamide treatment until information is available in the database will be used to describe how long patients receive treatment.

Completed

Looking for future studies?

Notify Me

Key information

Conditions

Metastatic Castration Sensitive Prostate Cancer (mCSPC) Cancer of the Prostate Genital Diseases Genital Diseases, Male Genital Neoplasms, Male Male Urogenital Diseases Neoplasms Neoplasms by Site Prostate Cancer Prostate Neoplasms Prostatic Diseases Prostatic Neoplasms Urogenital Diseases Urogenital Neoplasms

Age range

18 year and older

Sex eligibility

Male

Study type

Observational

Primary location

Pfizer, Inc

New York, 10001, United States

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

Male patients diagnosed with metastatic prostate cancer
Initiated apalutamide or enzalutamide for the first-line treatment of metastatic castration-sensitive prostate cancer (mCSPC). Initiation date of first treatment defines the index date.
Index date on or after 1 January 2020
Evidence of androgen deprivation therapy (ADT) use between 90 days prior to the index date and 6 months following the index date
Age ≥18 years on the index date -≥6 months of clinical activity following the index date, unless the patient died

Exclusion criteria

Evidence of castration-resistance prior to the index date
Received chemotherapy, androgen receptor pathway inhibitor, radiopharmaceuticals, immunotherapy, PARP inhibitor, or estrogens prior to the index date
Evidence of ADT use between 1 year and 91 days prior to the index date
Had a prior history of other cancers

Treatment and study plan

Enzalutamide

Drug

As provided in real-world setting

Other names: XTANDI

Apalutamide

Drug

As provided in real-world setting

Other names: ERLEADA

Primary outcomes

Treatment duration

Time frame: Up to approximately 65 months

Treatment duration will be defined as the time from index date to the discontinuation (i.e., addition of subsequent treatment, treatment gap of 90 days, death) of the index treatment for any reason. Patients without an event will be censored on the date of last confirmed clinical activity.

Sponsors and collaborators

Lead sponsor

Pfizer

Industry

Collaborators

Astellas Pharma Inc

Registry information

Official study title

Real-world Clinical Outcomes With Androgen Receptor Pathway Inhibitors (ARPIs) in Metastatic Castration-sensitive Prostate Cancer (mCSPC) in the Flatiron Health Electronic Health Records (EHR) Database

Important dates

Study start: 2025
Primary completion: 2025
Study completion: 2025
First posted: Jul 25, 2025
Registry last updated: Dec 8, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Published trials that share one or more normalized conditions with this study.

Recruiting