A Study to Learn About Novel Hormonal Therapies (NHTs) for Metastatic Castration-sensitive Prostate Cancer (mCSPC) in People Who Were in the Armed Forces

Novel Hormonal Therapy (NHT) for Treating Patients With Metastatic Castration-Sensitive Prostate Cancer (mCSPC): An Analysis of National Veterans Affairs Health Care Network Data

The purpose of this study is to learn about- for how long are NHTs taken by men to treat mCSPC. NHTs in this study include study medicines:

• abiraterone,
• apalutamide,
• 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. Most prostate cancers need male hormones to grow. When cancer cells respond to treatment that lowers male hormones, this is known as castration-sensitive prostate cancer.

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 information from National Veteran's Affairs (VA) Health Care Network.

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

• were identified to have mCSPC.
• started treatment with NHT for mCSPC.
• were 18 years of age or older at start of NHT.

Men in this study will be taking NHT for treatment of their mCSPC. The study will explain:

• how long men take the therapy.
• how long it takes to start next therapy.

This study will use patient information about medications and treatments from VA data. This study will use information one year before start of NHT until information is available.

Study Overview

• Status: Completed
• Conditions: Prostatic Neoplasms
• Intervention / Treatment: Drug: Novel hormonal therapy

• Study Type: Observational
• Enrollment (Actual): 2313

Contacts and Locations

Study Locations

• United States
  • New York
    • New York, New York, United States, 10001
      • Pfizer Inc

Participation Criteria

Eligibility Criteria

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

• Sampling Method: Non-Probability Sample

Study Population

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 National Veterans Affairs Health Care Network.

Description

Inclusion Criteria:

• Male with ≥ 1 diagnosis claim for prostate cancer
• Had documented secondary metastasis code on or after the initial prostate cancer diagnosis
• Had initiated novel hormonal therapy (abiraterone, apalutamide, or enzalutamide) within 90 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
• ≥18 years old on index date
• Continuous enrollment for at least 365 days before index date

• Evidence to be castration-sensitive:

  • No prior surgical castration any time prior to the index date or no medical castration with ≥8 weeks of continuous use within -90 to -365 days prior to the index date, OR
  • Diagnosis of hormone sensitive malignancy status within 90 days before the index date

Exclusion Criteria:

• Evidence of castration-resistance prior to the index date

  • Received other prostate cancer treatment including NHT, non-steroidal anti-androgen (NSAA), chemotherapy, immunotherapy, radium 223, lutetium Lu 177 vipivotide tetraxetan, ketoconazole, or PARP inhibitor prior to the index date
  • Had diagnosis code indicating hormone resistance prior to the index date
  • A rise in prostate-specific antigen from the nadir by ≥2 ng/mL after castration
• Had a prior history of other cancers (except non-melanoma skin cancer)
• Participation in a clinical trial during the 30 days before the index date

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Novel hormonal therapy cohort; Patients initiating novel hormonal therapy (abiraterone, apalutamide or enzalutamide) for mCSPC	Drug: Novel hormonal therapy; As provided in real-world setting; Other Names: Abiraterone(Yonsa, Zytiga); Apalutamide(Erleada); Enzalutamide(Xtandi)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Duration of Therapy (DOT)	DOT was defined as the time from the index date to the date of NHT discontinuation for any reason. Discontinuation of the current NHT was defined as a treatment gap of at least 90 days (the last day with days' supply before the gap as discontinuation date), the initiation of a new therapy, or death, whichever came first. Initiation of a new therapy was defined by switching to a different NHT, switching to or augmentation with different therapies. Participants who did not experience discontinuation were censored at the end of data availability. Index date was defined as the initiation date of NHT in 1L (any date) from 1-January-2020 to 31-December-2022. Retrospective data was retrieved using the Veterans' Health Administration data for period of 01-Jan-2020 to 30-Sep-2023 (45 months).	From start of index treatment to date of NHT discontinuation or censoring date, whichever came first, during maximum follow-up of 45 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Time to Next Therapy (TTNT)	TTNT was defined as the time from the index date to the initiation date of a new therapy. Initiation of a new therapy was defined by switching to a different NHT, switching to different therapies. Participants who did not initiate a new therapy were censored at the end of data availability or death, whichever came first. Index date was defined as the initiation date of NHT in 1L (any date) from 1-January-2020 to 31-December-2022. Retrospective data was retrieved using the Veterans' Health Administration data for period of 01-Jan-2020 to 30-Sep-2023 (45 months). Kaplan-Meier method was used for analysis.	From start of index treatment until date of new therapy, or censoring date, whichever came first; during maximum follow-up of 45 months

Collaborators and Investigators

• Sponsor: Pfizer
• Collaborators: Astellas Pharma Inc
• Investigators: Study Director: Pfizer CT.gov Call Center, Pfizer

Publications and helpful links

Helpful Links

• To obtain contact information for a study center near you, click here.

Study record dates

Study Major Dates

• Study Start (Actual): November 22, 2023
• Primary Completion (Actual): April 23, 2024
• Study Completion (Actual): April 23, 2024

Study Registration Dates

• First Submitted: November 21, 2023
• First Submitted That Met QC Criteria: November 21, 2023
• First Posted (Actual): November 30, 2023

Study Record Updates

• Last Update Posted (Actual): June 4, 2025
• Last Update Submitted That Met QC Criteria: June 2, 2025
• Last Verified: June 1, 2025

More Information

Terms related to this study

• Keywords: enzalutamide; abiraterone; mHSPC; metastatic hormone-sensitive prostate cancer; mCSPC; treatment duration; metastatic castration-sensitive prostate cancer; time to next therapy
• Additional Relevant MeSH Terms: Urogenital Diseases; Genital Diseases; Genital Neoplasms, Male; Urogenital Neoplasms; Neoplasms by Site; Neoplasms; Genital Diseases, Male; Prostatic Diseases; Male Urogenital Diseases; Immune System Diseases; Prostatic Neoplasms; Hypersensitivity
• Other Study ID Numbers: C3431052; NCT06151418 (Registry Identifier: ClinicalTrials.gov)

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.