Eligibility Criteria for Comparison P

Inclusion Criteria

1. Patient still meets all eligibility criteria for registration in Section 4.4 of the STAMPEDE2 protocol.

2. Histological confirmation of prostate adenocarcinoma.

3. Patient meets the definition of SABR ineligible disease in Section 4.6 of the STAMPEDE2 protocol.

4. Patients must have adequate organ function as indicated by blood tests within 8 weeks prior to randomisation:
Bone marrow function 

a) ANC ≥1.5 x 10⁹/L.

b) Platelets ≥100 x 10⁹/L.

c) Haemoglobin ≥9g/dL, independent of transfusions for at least 28 days.

Hepatic function

a) Total bilirubin ≤2 x ULN. For patients with Gilbert’s Syndrome ≤3 x ULN is permitted.

b) ALT or AST ≤3 x ULN or ≤5 x ULN for patients with liver metastasis.

Renal Function

a) EGFR ≥50 mL/min/1.73m² calculated using the MDRD formula.

b) Albumin ≥25g/L.

5. Patient has started ADT and randomisation is ≤12 weeks since start of current ADT.

6. If relapsed, prior LHRH agonist/antagonist with or without first generation anti-androgen use in the adjuvant/neo-adjuvant setting, hormone treatment must have been discontinued >12 months prior to randomisation AND must not have exceeded 12 months of therapy AND must not have shown disease progression within 12 months of completing adjuvant/neo-adjuvant therapy.

7. WHO performance status 0-2 (see Appendix 1 of the STAMPEDE2 protocol).

8. Patient has provided signed informed consent for participation in Comparison P.

Exclusion Criteria

1. Prior treatment with any of the following:

a) Strontium-89, Samarium-153, Rhenium-186, Rhenium-188, Radium-223.

b) PSMA-targeted radioligand therapy.

2. Symptomatic cord compression, or clinical/radiological findings indicative of impending cord compression.

3. Any condition that precludes raised arms position.

4. Unmanageable bladder outflow obstruction or urinary incontinence. Note: bladder outflow obstruction or urinary incontinence which is manageable and controlled with best available standard of care (incl. drainage, pads) is permitted.

5. If taking part in the Imaging Substudy, contraindication to MRI (e.g., pacemakers, except MRI compatible pacemakers).