Personalised Cancer Vaccine
Over the past decade we have seen enormous strides in the management of cancer. There have been a number of different approaches, including immunotherapy, which have seen diseases which had previously not had really effective therapies demonstrate prolonged remission and in some cases cure.
One of the major problems with treating cancers is that the genetic make-up of an individual cancer is completely different between individuals. It has been suggested by some scientists, for example, that breast cancer is over 200 different diseases all bundled into the one diagnosis. Therefore, it is more logical to target each individual with therapy directed at their own particular cancer and its individualised, personalised genetic makeup.
A recent small but very powerful study published in Science Translational Medicine treated 25 women with advanced ovarian cancer. These women had been through standard chemotherapy and surgery. Stage IV ovarian cancer has a 17%, 5 year survival, making it one of the worst forms of cancer in the world.
This treatment regimen involved particular cells in the body known as dendritic cells which are basically the messengers that take up the antigen, which are the spikes on a tumour that give the personalised signature for that particular cancer. These dendritic cells are removed from the blood of the patient, are exposed to tumour extracts and then a chemical known as interferon gamma, which activates the immune response. The cells are then injected into the patient’s lymph nodes. These 25 women had the harvested dendritic cells injected every 3 weeks and most treatments continued for up to 2 years.
Around half the patients experienced a significant T-cell response to the individualised tumour and these responders survive longer with no tumour progression compared with the non-responders. In fact, the two-year overall survival rate in the responder group was 100% whereas it was only 25% in the non-responders.
One case study of a 46-year-old woman who had undergone 5 courses of chemotherapy for advanced ovarian cancer and was considered stage IV at the start of the trial had 28 doses of personalised vaccine over 2 years and has remained cancer free for 5 years.
Another approach used, this time for lymphoma, is known as CAR-T cell cancer treatment. This involves collecting the patient’s own T-cells and genetically modifying them in the laboratory including a gene to instruct the cells to target and kill the specific cancer involved. These T-cells are then infused back into the patients. A study published in the December 10, 2017 New England Journal of Medicine treated patients who had already failed standard therapy for lymphoma. 111 patients were given CAR-T treatment. 42% of the patients were in complete remission after a follow-up of around 15 months. They were, however, quite significant side effects from this therapy but the results are very promising.
Regardless, it appears that medical science is edging closer to a cure for cancer which was once typically a death sentence.