Researchers from The University of Manchester, a branch of the Manchester Cancer Research Centre, have verified the potential of a drug that enhances the overall effectiveness of radiotherapy in halting tumor growth and progression.

Utilizing the body's own immune system to attack tumor cells has been garnering a lot of attention and interest of late. It is a plausible strategy that can be quite impactful without having the risk of side effects that are usually associated with standard chemotherapy.

Skin cancers have been successfully treated using a topical cream, imiquimod, which rounds up immune cells through a molecule known as toll-like receptor 7 (TLR7), a protein that has the ability to identify foreign and potentially harmful substances.

Previously, researchers from Manchester have demonstrated that they can also stimulate the immune system into producing an immune response against non-skin cancers by injecting an agent similar to TLR7 into the blood.

In cooperation with AstraZeneca and Dainippon Sumitomo Pharma, the Manchester group have examined another molecule that triggers TLR7, known as DSR-6434. Using mouse models of two different types of cancer, they explored DSR-6434 on its own and in accordance with radiotherapy and measured the effect on the prime tumor and the number of secondary tumors in the lungs.

"We have already seen a strong immune system response from other immunotherapy agents in combination with radiation - this new agent appears to be even more potent," said Professor Ian Stratford, from Manchester Pharmacy School who, with Professor Tim Illidge, spearheaded the research recently published in the International Journal of Cancer.

Stratford's team demonstrated that administering DSR-6434 in conjunction with radiotherapy led to tumor shrinkage and increased long-term survival. They discovered that the combination treatment also diminished the risk of occurrence of secondary lung tumors.

"It looks like there's good reason to use radiotherapy alongside immunotherapy agents in the treatment of solid tumors. These results strongly suggest that this sort of combination therapy should be evaluated in clinical trials with cancer patients," added Stratford.