Chemoradiation With Enadenotucirev as a Radiosensitiser in Locally Advanced Rectal Cancer

The use of chemoradiotherapy (CRT), in combination with surgery is the standard of care in the treatment of locally advanced rectal cancer. However some patients don't respond well to radiation. More advanced radiotherapy techniques, that result in fewer toxicities, means that we are now able to combine new anti-cancer agents into standard treatment. Targeting the tumour early in this way has the potential to improve response rates. Enadenotucirev is a specific type of anti-cancer virus that only targets cancer cells. It acts in the same way as any virus and can only survive by replicating inside cancer cells and not normal, non-cancerous cells. This means that it can selectively target and destroy tumours, without directly affecting normal cells. It also has the ability to attract cells from the body's immune system to help fight the cancer. The addition of enadenotucirev to standard chemoradiotherapy treatment may have a combined effect on the cancer cells with potentially few, additional side effects. This trial aims to determine the optimal dose and frequency of the virus to give by gradually increasing the number of doses each successive patient receives, and then increasing the dose of the virus itself. Each patient will receive a minimum of 3 doses, up to a maximum of 8, spread over the course of their 5 week standard chemoradiotherapy treatment. Patients will be closely monitored at all times to ensure that with each dosing group, there aren't excessive side effects. Patients will then undergo surgery as part of their standard of care and be followed up for up to 4-6 weeks post-surgery. This trial aims to determine the optimal dose and frequency that can then be used in future studies with the possibility of exploring the addition of Enadenotucirev to other chemoradiotherapy treatments.