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

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