This is an observational study in which patient data from the past on men with prostate cancer are studied.

Cancer is a condition in which the body cannot control the growth of cells and tumors may form. If tumors form in the prostate, male sex hormones (androgens) can sometimes help the cancer spread and grow. Cancer that spreads to other parts of the body is called metastasis.

Androgens are mainly made in the testicles. There are treatments available for men with prostate cancer to lower the levels of these hormones in the body. These treatments are called androgen deprivation therapy (ADT). Some men with prostate cancer respond to ADT, but in some cases, prostate cancer may overcome the therapy and worsen despite low androgens levels.

Second generation androgen receptor inhibitors (SGARIs) including darolutamide, apalutamide, and enzalutamide are available for the treatment of prostate cancer in addition to ADT. SGARIs work by blocking androgens from attaching to proteins in cancer cells in the prostate.

Clinical studies have shown that men with prostate cancer benefit from these treatments. But besides benefits, unfavorable reactions related to these treatments also influence which treatment is chosen, if the treatment is taken as intended or if it is even stopped.

Unfavorable reactions observed for darolutamide, apalutamide, and enzalutamide differ from each other. In clinical trials, severe unfavorable reactions occurred less often for darolutamide.

But information on how unfavorable reactions of each treatment influence their intake in actual or "real-world" prostate cancer treatment is missing.

The main aim of this observational study is to learn to what extent SGARI treatments are taken as prescribed and how often their intake is completely stopped. To find this out, researchers will collect available treatment data of adult men with prostate cancer from the United States who started SGARI treatments between August 2019 and March 2021. The data will be drawn from the IQVIA database.

For each man, data from up to 1 year prior SGARI treatment until at least 3 months after treatment start (up to the 30 June 2021) will be collected.

The researchers will look at the percentage of men who:

• completely stopped to take their treatment or
• took the treatment as prescribed.

The results for each treatment (darolutamide, apalutamide, and enzalutamide) will then be compared to find possible differences.

There will be no required visits with a study doctor or required tests in this study since only patient data from the past are studied.

Inclusion Criteria:

• Have at least 1 prescription claims for enzalutamide (National Drug Code [NDC]: 00469-0125-99, 00469-0625-99, 00469-0725-60), apalutamide (NDC: 59676-600-12, 59676-600-56, 59676-600-99) or darolutamide (NDC: 50419-395-01, 50419-395-72) during the index identification period.

  -- The date of the earliest SGARI claim to occur during this period will be defined as the index date with the corresponding SGARI as the index treatment.

• Have ≥1 diagnosis of prostate cancer (ICD-10 code C61.) during the overall baseline period.

• Age ≥18 years and male gender on the index date.

• Have continuous health plan enrollment with medical and pharmacy benefits for at least 6 months prior to the index date.

• Have continuous health plan enrollment with medical and pharmacy benefits for at least 3 months after the index date and throughout the follow-up period.

Exclusion Criteria:

• Since patients should not be prescribed more than one SGARI when initiating treatment, patients with more than one SGARI prescribed on the index date will be excluded from the study. This will allow each patient to be assigned to a single study cohort.
• In order to select patients who are initiating SGARI treatment, patients with the index SGARI treatment during the 1 year baseline period will be excluded from the study.

All patients diagnosed with Prostate Cancer who newly initiate Second Generation Androgen Receptor Inhibitors treatment in United States from 01 Aug 2019 to 31 Mar 2021.

Availability of this study's data will later be determined according to Bayer's commitment to the EFPIA/PhRMA "Principles for responsible clinical trial data sharing". This pertains to scope, timepoint and process of data access. As such, Bayer commits to sharing upon request from qualified researchers patient-level clinical trial data, study-level clinical trial data, and protocols from clinical trials in patients for medicines and indications approved in the US and EU as necessary for conducting legitimate research. This applies to data on new medicines and indications that have been approved by the EU and US regulatory agencies on or after January 01, 2014.

Interested researchers can use www.vivli.org to request access to anonymized patient-level data and supporting documents from clinical studies to conduct research. Information on the Bayer criteria for listing studies and other relevant information is provided in the member section of the portal.