The ADAPT study is an observational study of apalutamide, which can be given to patients with hormone sensitive metastatic prostate cancer as standard of care. The clinical decision for patients to have apalutamide as part of their management plan will be decided by the clinician. The patient will only be approached about the ADAPT study if they decide they want to have apalutamide as part of their management.

The aims of the ADAPT study include documenting the biochemical effectiveness, as determined by the Prostate-Specific Antigen (PSA) and impact of apaluatmide on health related quality of life. The blood test for PSA is regularly monitored as standard of care.

Additionally, the impact of apalutamide on fatigue, cognitive function, patients reported outcomes, health related quality of life will be evaluated using patient questionnaires answered at defined timepoints. The questionnaires will be sent either electronically or via post at week 12, 24, 36, 48, 72 and 104 weeks after commencement of apalutamide.

Currently, the majority of data regarding tolerability and biochemical response to apalutamide has been from large phase III trials, where there are strict eligibility criteria. Real-world data as from the ADAPT study can provide valuable complementary data to randomised controlled trials, which can be used to address the 'generalizability' limitations of randomised control trials and can provide evidence on the external validity of their findings. This information can advance knowledge of patterns of care, treatment effectiveness and side-effects and inform clinical practice to improve outcomes.

Inclusion Criteria:

• Male 18 years of age or older
• Histologically confirmed diagnosis of adenocarcinoma of the prostate with both:
• Metastatic hormone sensitive prostate cancer
• Treatment decision for apalutamide by clinician

Exclusion Criteria:

• Non-metastatic prostate cancer
• Prior chemotherapy / abiraterone / apalutamide / darolutamide / enzalutamide for prostate cancer
• Unable to complete patient reported outcome questionnaires

Males 18 years of age or older, with metastatic hormone sensitive prostate cancer