A Study to Learn About the Outcomes Between Study Medicines, Enzalutamide and Darolutamide Among Men With Metastatic Castration Sensitive Prostate Cancer (mCSPC)

Real-World Outcomes Among Patients Receiving Enzalutamide Plus ADT or Darolutamide Plus ADT in Metastatic Castration Sensitive Prostate Cancer (mCSPC)

The purpose of this real-world study of electronic medical records is to look back to compare the time to next treatment after initial treatment with enzalutamide or darolutamide in addition to androgen deprivation therapy (ADT). ADT is a hormone therapy used to stop testosterone from being released or to prevent it from acting on prostate cells. The study includes men with metastatic castration-sensitive prostate cancer (mCSPC). This is a cancer that has spread outside the prostate to other parts of the body, but can still be successfully managed by lowering male hormones like testosterone. The study uses data from the Flatiron's Prostate Cancer Panoramic Database. This data base contains information on prostate cancer patients such as their clinical characteristics, lab, vitals, treatments and outcomes.

This study is seeking participants included in the Flatiron Prostate Cancer Panoramic dataset who:

• Have a diagnosis of prostate cancer (PC) that has spread to other parts of the body
• With at least two documented clinic visits on different days in the Flatiron network occurring on or after 01 January 2011
• Has proof of treatment with enzalutamide or darolutamide in combination with ADT as a first line treatment
• The treatment with enzalutamide or darolutamide in combination with ADT is no more than 30 days prior to or 6 months after the mCSPC diagnosis date

All participants in this study received at least 1 dose of enzalutamide or darolutamide in combination with ADT. The experiences of the participants receiving the enzalutamide or darolutamide will be looked at.

Participants will take part in this study for at least 6 months. During this time, they will have at least 2 documented clinic visits from 01 January 2011 to 31 March 2026. These visits will be updated if newer information becomes available at the time of the analysis.

Study Overview

• Status: Not yet recruiting
• Conditions: Metastatic Castration Sensitive Prostate Cancer (mCSPC)
• Intervention / Treatment: Drug: darolutamide plus androgen deprivation therapy; Drug: Enzalutamide plus androgen deprivation therapy

• Study Type: Observational
• Enrollment (Estimated): 4700

Contacts and Locations

• Study Contact: Name: Pfizer CT.gov Call Center; Phone Number: 1-800-718-1021; Email: ClinicalTrials.gov_Inquiries@pfizer.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

This is a retrospective cohort study of patients with mCSPC initiating first-line (1L) enzalutamide plus ADT or darolutamide plus ADT without other life-prolonging therapies in the US identified from the Flatiron's Prostate Cancer Panoramic Database. The dataset will include all protocol-required, retrospective patient-level data available for eligible patients from 01 January 2011, through the expected data cutoff date of 31 March 2026, which may be updated if newer data cuts become available at the time of the analysis.

Description

Patients must meet all of the following inclusion criteria to be eligible for inclusion in the study:

1. Patients included in the Flatiron Prostate Cancer Panoramic dataset:

   1. Has an International Classification of Diseases (ICD) diagnosis of PC (ICD-9 185x or ICD-10 C61x)
   2. At least two documented clinic visits on different days in the Flatiron network occurring on or after 01 January 2011
   3. Has evidence of diagnosis of PC with an initial or metastatic diagnosis date.

2. Evidence of mCSPC diagnosis date, as defined below:

   a. The mCSPC diagnosis date is determined using information on the date of metastatic diagnosis and the CSPC status. The data of metastatic diagnosis is the earliest date of the first confirmation of metastatic prostate cancer using the following hierarchy, where available: 1) Biopsy specimen collection date from the pathology report; 2) Physician reported date of biopsy; 3) Date of the radiology scan that indicated metastatic disease, if it was later confirmed by the physician; 4) Physician reported date of metastatic diagnosis. CSPC status is determined based on the following hierarchical evidence sources: 1) metastatic diagnosis date (if metastatic at initial diagnosis); 2) Explicit clinician documentation of CSPC; 3) Earliest ADT start date; 4) Clinician documented response or PSA decline while on ADT

3. Has evidence of treatment with enzalutamide or darolutamide in combination with ADT in the 1L mCSPC setting , on or after 01 August 2022.

   Note: The index date is the start of the ARPI in combination with ADT (i.e., the first episode of ARPI treatment, which can occur up to 90 days after initiation of 1L therapy if ADT is initiated before the ARPI).

4. Index date is no more than 30 days prior to or 6 months after the mCSPC diagnosis date

Patients meeting any of the following criteria will not be included in the study:

1. Birth sex reported as female or unknown
2. Age <18 years at index date
3. Evidence of receiving a clinical study drug on or prior to index date
4. Diagnosed with neuroendocrine and/or small cell PC on or prior to index
5. Diagnosed with additional malignancies, excluding nonmelanoma skin cancer, at any time prior to index date
6. Index date <6 months prior to data cutoff date
7. Received multiple ARPIs or ARPI in combination with any drug other than ADT or first-generation anti-androgen treatments prior to and up to 28 days after index date
8. Evidence of ADT or first-generation anti-androgen treatment between 1 year and 91 days prior to index date
9. Evidence of an orchiectomy occurring more than 90 days prior to index date
10. Evidence of CRPC any time prior or up to 90 days after the index date
11. Evidence of treatments for mCRPC on or prior to index date
12. Has a Line 0 as defined by Flatiron line of therapy (LOT) business rules, indicating potentially missing treatment data at the start of mCSPC setting
13. Received docetaxel prior to and up to 120 days after index date

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
darolutamide plus androgen deprivation therapy	Drug: darolutamide plus androgen deprivation therapy; As provided in real world setting
enzalutamide plus androgen deprivation therapy	Drug: Enzalutamide plus androgen deprivation therapy; As provided in real world setting

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Median Real-world time to next treatment (rwTTNT)	time from index date to the start of the next treatment course (August 1, 2022- March 31, 2026)

Collaborators and Investigators

• Sponsor: Pfizer
• Investigators: Study Director: Pfizer CT.gov Call Center, Pfizer

Study record dates

Study Major Dates

• Study Start (Estimated): September 1, 2026
• Primary Completion (Estimated): November 15, 2026
• Study Completion (Estimated): November 15, 2026

Study Registration Dates

• First Submitted: August 18, 2026
• First Submitted That Met QC Criteria: August 18, 2026
• First Posted (Actual): August 21, 2026

Study Record Updates

• Last Update Posted (Actual): August 21, 2026
• Last Update Submitted That Met QC Criteria: August 18, 2026
• Last Verified: August 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Hormones, Hormone Substitutes, and Hormone Antagonists; Hormone Antagonists; Pharmacologic Actions; Chemical Actions and Uses; Androgen Antagonists; darolutamide; enzalutamide
• Other Study ID Numbers: C3431054

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: 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.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No