New Immunology Technique

The blog that Sloan-Kettering Cancer Center runs reports on a new Immunotherapy technique that could be a boon for treating all types of cancers, including blood cancers.

The technique is called Adoptive Cell Transfer (ACT), and is an improvement on previous attempts at this kind of Immunpotherapy.

Immunotherapy approaches try to find ways train the body's natural defenses to recognize and attack cancer cells the way they would any other invader. This is hard, because 1) cancer cells aren't really "invaders," as such, since they come from the patient's own body, and 2) cancers are smart as hell and develop additonal ways to protect themselves from the immune system.

Some immunotherapies target a single antigen on a cancer cell. Rituxan, for example, targets the CD20 protein on the surface of B cells. The problem, as successful as Rituxan has been, is that both cancer cells and healthy B cells have CD20. So you get a little bot of collateral damage. There's no antigen that exists only on cancer cells, so that kind of damage to at least some healthy cells is unavoidable with most immunotherapies.

ACT is different because it is able to target two antigens on the surface of cancer cells, something much more likely to be unique to cancer cells. That is, few healthy cells have combinations of antigens that cancer cells have. Follicular NHL cells often have, for example, CD20 and CD22. A therapy that targeted both could help keep some healthy cells safe.

It works by removing some T cells from the patient's body (these are white blood cells that naturally attack invaders), and training them to recognize the antigens. The cells are then reintroduced into the patient and get to work.

The article discusses work done with prostate cancer cells, and it looks promising.

The problem, if I can extend the lymphoma example, is that not all Follicular NHL patients have the CD20 or the CD22, let alone both of them. So these therapies will need to be matched to individual patients. this isn't necessarily a big deal; it's not like every patient has his or her own set of antigens that no one else has. But it will be an extra step. On the other hand, that kind of individualized approach is gaining steam anyway.

More advances. Always nice to see.