New method aims to provide safer cell-based immune cancer therapies

A new method has proven effective at developing more specific, cell-based immune therapies for cancer, findings show.

Michael Sadelain, MD, PhD, director of the Centre for Cell Engineering at Memorial Sloan-Kettering Cancer Centre, led a team which found the use of patients' own immune cells can be successful in treating a number of blood cancers, such as selected types of leukaemia.

The treatment has been reported in Nature Biotechnology and is known as adoptive cell transfer and involves engineering a T cell, which are later removed from a patient and added with a gene to enable them to recognise a specific antigen on the surface of cancer cells.

Later, these enhanced cells are grown in the laboratory and infused back into a patient to find and attack cancer.

These findings come after David Cameron announced plans to map the DNA of thousands of NHS cancer patients in an effort to improve the understanding of the disease.

The decision means UK will be the first country to launch technology to allow 100,000 cancer sufferers to have their full genome sequenced.

Mr Sadelin's team uses chimeric antigen receptors (CARs) in their work, allowing T cells to target antigens on the surface of tumour cells, while a chimeric costimulatory receptor (CCR) will be utilised to help T cells recognise a second antigen.

CARs and CCRs combine in a process titled balanced signalling, as the presence of either on their own is not sufficient to trigger an immune response.

As part of the study, the researchers developed T cells that carried a CAR for an antigen called PSMA, while a CCR was developed for the PSCA antigen. Both PSMA and PSCA are found on prostate cancer cells.

"We are getting better at working with these T cells and enhancing them so that we can get a powerful immunological response against cancer. The dilemma now is that we are concerned with limiting these responses and making them as targeted as possible to avoid potentially harmful side effects," Mr Sadelain explained.

Posted by Neil Clark