NEOadjuvant PembRolizumab In Stratified Medicine - ColoRectal Cancer

Colorectal cancer (CRC) is the 2nd to 3rd most common malignant disease in developed countries, with over 1 million new cases and 500,000 deaths worldwide each year. The primary treatment for early stage CRC is surgery to remove the tumour, which is possible in 80% of patients. Even after surgery up to half of patients will develop recurrence or spread of the disease (metastases) which is incurable. Survival after 5 years is approximately 14% for patients with metastatic disease. Clinical trials using immunotherapy drugs called 'immune checkpoint inhibitors' have shown excellent results in advanced colorectal cancer patients who have certain genetic characteristics called 'mismatch repair deficiency (MMR-d)' and 'high microsatellite instability (MSI-h)'. The benefits of immunotherapy as a treatment prior to surgery to remove the tumour (neoadjuvant treatment) has been observed in both melanoma and in glioblastoma with enhanced local and systemic anti-tumour responses.

Pembrolizumab is an immunotherapy drug and works by helping the body's own immune system to fight the cancer cells. The NEOPRISM-CRC trial will investigate whether giving pembrolizumab before surgery is safe, whether it improves the chances of the tumour being removed completely and whether it delays or prevents the cancer from coming back.

Pembrolizumab treatment lasts for a maximum of 9 weeks (maximum of 3 cycles of treatment, each cycle consisting of 3 weeks) and is given prior to surgery. Following surgery patients will be followed up for at least 3 years after their surgery and to a maximum of 5 years. Target recruitment is 88 patients and recruitment is expected to take place over a 48 month period.

Blood, tissue, mouth swabs and stool samples will be collected from patients throughout the trial to better understand the biology of immunotherapy as a treatment for CRC prior to surgery.