Bespoke cancer trials edge closer

A major British discovery is expected to lead to revolutionary bespoke treatments for patients with advanced cancer. It could enter trials within two years.

Researchers have spotted rare ‘flag’ proteins that act as immune system targets and are displayed on the surface of all of a patient’s tumour cells, wherever they might be in the body. Normally they are shielded from the immune system, or missed because rapidly-evolving cancers present too many constantly changing targets.

Once the omnipresent proteins, or ‘antigens’, are isolated, potent immune system cells called T-cells can be employed as homing missiles to zero in on them and destroy the cancer. Such an approach, which involves mapping the DNA in a patient’s tumour sample, would help to overcome the ability of cancers to resist therapies by altering their genetic make-up.

The work is at an early stage and so far just two of the special antigens, plus the T-cells that recognise them, have been identified in two lung cancer patients. However, the scientists hope to see rapid progress leading to patient trials, and are optimistic about similar targets for other cancers being found.

Professor Charles Swanton, from University College London’s Cancer Institute, a leading member of the Cancer Research UK-funded team, said: “I will be disappointed if we haven’t treated a patient within two years. Do we think it’s going to work? I hope this is going to result in improvements in survival outcomes. If this doesn’t work I’ll probably hang my hat up and do something else.”

He said a tumour evolutionary tree is like a “snowflake or fingerprint”, unique to each patient. That presents a problem for clinicians and patients, because as tumours develop the tree grows new branches containing novel genetic mutations which help the cancer resist treatment. The new research shows there are potential immunotherapy targets from the ‘trunk’ of the tree that are flagged up on all of a tumour’s multiplying cells.

Prof Swanton added: “This is exciting. Now we can prioritise and target tumour antigens that are present in every cell, the Achilles heel of these highly complex cancers. This is really fascinating and takes personalised medicine to its absolute limit, where each patient would have a unique, bespoke treatment.”

Experts are increasingly coming round to the idea that the future of cancer treatment is personalised medicine, tailored to small groups of patients or even individuals.

A new more effective approach to tackling cancer is desperately needed, Prof Swanton believes. He said 71 new anti-cancer drugs approved by the US Food and Drug Administration over a period of 12 months were associated with a typical survival time of no more than two months. On average, each course of treatment costs €90,800 .

Prof Swanton added: “This is the emperor of all maladies. It’s just a massive challenge, because this disease is unlike all other diseases that we see in medicine.

“We’re dealing with an entity that’s constantly evolving, constantly adapting, and constantly changing its genome,” he said.