Chemoradiation With Enadenotucirev as a Radiosensitiser in Locally Advanced Rectal Cancer — CEDAR  

Locally Advanced Rectal Cancer Clinical Trial

Official title: A Phase 1 Trial of the Safety, Tolerability and Biological Effects of Intravenous Enadenotucirev, a Novel Oncolytic Virus, in Combination With Chemoradiotherapy in Locally Advanced Rectal Cancer

Status Completed

Clinical Trial Summary

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 6, 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.

Clinical Trial Description

At present identifying novel radiosensitising agents in colorectal cancer is an area of high need for patients considering sphincter preserving surgery or needing down staging to facilitate surgery.

Although the combination of Enadenotucirev with chemoradiation is novel, there is a wealth of evidence to support the rationale for combining this class of agent with radiation and chemotherapy.

Enadenotucirev is a group B oncolytic virus under development for the systemic treatment of metastatic or advanced epithelial tumours. Enadenotucirev is a chimeric adenovirus type 11p (Adp/adenovirus type 3 (Ad3) virus, discovered through a process of bio-selection from a library of chimeric viruses produced from a pool of adenoviruses from seven different serotypes utilizing human HT-29 colorectal cancer (CRC) cells.

Enadenotucirev shows selective and potent toxicity in humans carcinoma cells with only very limited or no toxicity to normal (non-cancerous) human cells. Other than humans, there is no known permissive species for Enadenotucirev. The principle advantage of oncolytic therapy is that the virus replicates only in diseased cells meaning that the concentration of drug is amplified at the site of pathology so that it is higher in the tumour than in healthy tissue. Virus particles spread from cell to cell within a tumour nodule until they reach non-permissive normal tissues, in principle destroying all viable tumour cells they encounter.

While the overall understanding of the mechanism of action of Enadenotucirev in humans is still under investigation, it is now well established from non-clinical and clinical studies that the mechanism of anti-cancer efficacy of oncolytic viruses not only involves direct infection and lysis of tumour cells, but that immune responses stimulated via an increased release of tumour-associated antigens and immune-inflammatory activation signals play a key role.

CEDAR is dual endpoint, dose escalation phase 1 trial using a time to event continual reassessment method (TiTECRM). Response and Toxicity endpoints will be combined in dose escalation models to identify the optimal dose schedule. Dose decisions are made using the statistical model instead of just using the data from that particular dose, as in the case of 3+3 model, meaning it uses all available data to make a dose decision.

This primary objective is to determine the optimal dose and frequency of the virus by firstly gradually increasing the number of doses each successive patient receives, and then increasing the dose of the virus itself. All participants will receive 3 loading doses in weeks 1-2, prior to initiation of standard chemoradiotherapy. Further doses of Enadenotucirev will either be given after or during and after standard chemoradiotherapy and this is dependent on which of the 4 different dose groups they are assigned to. The dose given will vary between either 1x1012 Viral Particles (VP) or 3x1012vp.

Each patient will receive a minimum of 3 doses, up to a maximum of 6, spread over the course of 9 weeks. 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 4-6 weeks after surgery. ;

Related Conditions & MeSH terms

• Locally Advanced Rectal Cancer
• Rectal Neoplasms

• NCT number: NCT03916510
• Study type: Interventional
• Source: University of Oxford
• Status: Completed
• Phase: Phase 1
• Start date: July 1, 2019
• Completion date: February 24, 2023