ANZUP2001: This phase II study is trying to understand whether radiation therapy (177Lu-PSMA-617) is more safe and effective alone, or in combination with immunotherapy (ipilimumab and nivolumab), in people with metastatic, castration resistant prostate cancerPhase II Study of Radionuclide 177Lu-PSMA Therapy Versus 177Lu-PSMA in Combination With Ipilimumab and Nivolumab for Men With MetastaticCastration Resistant Prostate Cancer (mCRPC)

Exclusion

1. Prostate cancer with known significant sarcomatoid, spindle cell or neuroendocrine cell components, or metastasis of other cancers to the prostate.
2. 18F-FDG-PET/CT SUVmax ≥10 at a site of measurable disease with no concurrent PSMA expression > 10mm
3. Prior treatment with anti-PD1, anti-PD-L1/L2, anti-CTLA-4 antibody, or any other antibody or drug specifically targeting T cell co-stimulation or checkpoint pathways.
4. Patients must not have had more than one line of chemotherapy. If a patient has had docetaxel chemotherapy for hormone sensitive or castrate resistant setting, this will be considered one line.
5. Prior treatment with 177Lu-PSMA.
6. Patients with active, known, or suspected autoimmune disease. Sjogren's syndrome is considered an autoimmune disease. Exceptions: Patients with vitiligo, type I diabetes mellitus, residual hypothyroidism due to an autoimmune condition only requiring hormone replacement, or conditions not expected to recur in the absence of an external trigger, may be eligible.
7. Patients with a condition requiring systemic treatment with either corticosteroids (>10mg daily prednisone equivalents) or other immunosuppressive medications within 14 days of registration. Inhaled or topical steroids, and adrenal replacement doses ≤ 10 mg daily prednisone equivalents are permitted in the absence of active autoimmune disease.
8. Participants must have recovered from all AE due to previous therapies to ≤Grade 1 or baseline. Participants with ≤ Grade 2 neuropathy may be eligible.
9. Active malignancies within the previous 2-years with >30% probability of recurrence within 1 year. Melanoma in situ, basal cell or squamous cell carcinomas of skin, are permitted.
10. Significant infection, including chronic active hepatitis B, hepatitis C, or HIV. Testing for these is not mandatory unless clinically indicated.
11. Radiation or surgery within 2 weeks of randomisation.
12. Previous history of interstitial lung disease or non-infectious pneumonitis.
13. Administration of a live vaccine within 30 days prior to the first dose of study drug.
14. Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements.
15. Inadequate contraception. Men must have been surgically sterilised or use a (double if required) barrier method of contraception.