Adoptive T cell therapy, advanced melanoma and survival

Immunotherapy is a quickly evolving field, offering cures for diseases that were previously terminal. It can be used to combat a wide range of diseases, from cancer to psoriasis, by inducing, enhancing or suppressing the body’s own immune response. Its use in oncology has been a topic of extensive research in recent years with new treatments having the potential to drastically improve survival rates and quality of life.

A newly emerging immunotherapy for advanced metastatic melanoma is adoptive T cell therapy, a costly and physically demanding treatment that “sharpens” the patient’s T cells. The cells are extracted, cultured and reinjected in far greater numbers allowing them to seek out and fight the tumour cells more effectively.

Around half of all patients with advanced melanoma who have been given the therapy responded to treatment. 10?20% of patients can be cured with a single treatment, however its intensive nature can lead to numerous side effects highlighting the importance of suitable candidate selection.

At Lund University Sweden and Herlev University Hospital Denmark, a small study of 25 patients who have all undergone adoptive T cell therapy took place. The researchers analysed the patients’ tumour cells at the molecular level, revealing that the greater the number of mutations within the tumour, the greater the efficacy of adoptive T cell therapy. This phenomenon is due to new antigens being produced each time the tumour mutates. Like a game of hide and seek, the more neoantigens present in the body the easier it is for the T cells to find them, therefore more mutations means more neoantigens for the immune system to recognise, increasing the immune response.

Due to the specialist nature of the treatment, it is only offered in a few places worldwide, hence the sample size is small. However, the results clearly show that patients can exhibit long-term benefits on the molecular level from the treatment, nevertheless more research and larger trials are needed to validate these results.