NEPTUNES is a single arm, multicentre phase II study for patients with metastatic prostate adenocarcinoma which has not responded to 1st line treatments with androgen blockage.

There are 2 stages.

The first stage is Pre-screening where patients will have a sample of their cancer tissue tested for the specific immunogenic signature which is thought to be most amenable to immunotherapy.

If the cancer tissue is positive, and the patient is eligible to continue, they will be enrolled into the Main Study. Here they will receive treatment with combination therapy of Ipilimumab and Nivolumab, followed by monotherapy with Nivolumab.

Patients registered to the Main Study will receive up to 4 doses of the combination therapy of Nivolumab and Ipilimumab over 9 weeks, after which they will receive up to 10 cycles of Nivolumab therapy over 1 year.

Patient will be followed up for up to 5 years following registration to the Main Study. This follow up consists of 12 weekly visits for the first 2 years and 6 monthly visits thereafter.

Patients must have histologically confirmed metastatic prostate adenocarcinoma, undergone at least one line of systemic treatment and have documented progression of the cancer in the past 6 months.

Patients cannot be included if they have had prior treatment with Sipuleucel-T, immune checkpoint targeting agents or other novel immune-oncology agents.