A Trial of 177Lu-PSMA617 Theranostic Versus Cabazitaxel in Progressive Metastatic Castration Resistant Prostate Cancer

Despite recent advances in the treatment of prostate cancer, metastatic disease remains incurable. Prostate specific membrane antigen (PSMA) is present in high quantities on the cell surface of prostate cancers, and is also further increased in metastatic hormone refractory carcinomas. PSMA is an attractive target for both imaging and treatment of prostate cancer. PSMA bound to the radioactive substance Gallium68 (GaPSMA) is rapidly being adopted for imaging prostate cancer using positron emission tomography (PET) scanning. Radionuclide therapy is an approach for the treatment of cancer that uses tumour targeting agents to deliver high doses of radiation to sites of tumours. The PSMA molecule used for PET imaging can also be labelled with Lutetium177 (Lu177), a radioactive substance. The aim of this study is to determine the activity and safety of LuPSMA radionuclide therapy. Patients with metastatic prostate cancer who have progressed despite hormonal therapy and chemotherapy, will be randomised to receive either LuPSMA radionuclide therapy (up to a maximum of 6 cycles of therapy) or cabazitaxel chemotherapy (up to a maximum of 10 cycles of therapy). 200 participants will be recruited from sites across Australia. The study will determine the effects on PSA response rate (primary endpoint), pain response, progression free survival, quality of life, and frequency and severity of adverse events. Correlative outcomes include associations between PET imaging and clinical outcomes, and biomarkers and clinical outcomes.