Thalidomide itself is already showing promise, in combination with chemotherapy, for treating some forms of cancer. But the new research suggests that subtly different forms of Thalidomide could be even more effective in treating the disease.
The new drugs seem to work in three ways. They reduce inflammation, stimulate the immune system to attack cancer, and new results show that, like Thalidomide, they reduce blood flow to the tumour.
Thalidomide gained notoriety in the 1960s when doctors discovered that it caused birth defects by limiting the development of new blood vessels to growing limbs.
But experts believe that this property of limiting blood flow can be harnessed to treat cancer by starving a tumour of its blood supply. Without a supply of blood a tumour cannot continue to grow.
The researchers looked at two different versions of the drug called IMiDs and SelCIDs and found that they were at least ten times as potent at preventing the growth of blood vessels than Thalidomide.
The research, carried out at St George’s Hospital Medical School in London, also shows that these drugs can stimulate the immune system, enhancing the body’s natural anti-cancer defences or help reduce cancer-causing inflammation.
Dr Keith Dredge, author of the study, says: “This group of Thalidomide-like drugs seems to have very complex and yet very exciting properties.”
The body’s immune system has the potential to recognise cancer cells at a very early stage. A type of blood cell, called killer T cells, can then destroy the cancer cells before a tumour from develops. Unfortunately the immune system isn’t always powerful enough to do the job.
“These new drugs have the potential to stimulate the immune system which could help prevent cancer,” says Dr Dredge.
“Conversely, inflammation, which also occurs naturally in the body, may contribute to the development of cancer and our research shows that Thalidomide-like drugs can reduce inflammation.”
Two forms of ImiD are already being used in early clinical trials for treating advanced cancer, one at St. George’s and another at Guy’s Hospital, also in London.
Sir Paul Nurse, Chief Executive of Cancer Research UK which publishes the British Journal of Cancer, says: “Thalidomide and drugs like it are showing a great deal of promise in cancer research.
“It is heartening to think that Thalidomide, with all its tragic associations, could become a new weapon against cancer.”
- British Journal of Cancer87 (10)
IMiDs and SelCIDs are abbreviations for Immunomodulatory Drugs and Selective Cytokine Inhibitory Drugs. This research has been funded by Celgene Corporation, based in New Jersey.