Last-resort cancer therapy holds back disease for more than a decade
CAR-T therapy is incredibly complex and incredibly cool.One of the reasons CAR-T therapy has been so successful thus far with certain lymphomas and some leukemias is that there is a specific surface protein (CD19) which is expressed in all B-cells (the deranged lineage in the case of lymphoma) and is also not expressed by any other cells in the body. By engineering a patient's T-cells to target CD19, you create a highly sensitive and specific attack that recruits their own immune system to annihilate the entire B lineage population.One problem we run into when trying this for other cancers (like, that don't come from B-cells) is that it's been really hard to find such a nicely specific surface protein, as well as an entire population of cells you can just annihilate and be survivable for the patient. Most surface proteins are expressed in varying degrees throughout various different organs in the body, so a CAR-T against it would cause a ton of off-target effects. In some early trials for certain cancers they encountered this with unfortunate side effects (including in some cases death). Nevertheless, there is lots and lots of research still ongoing in the field, which is super exciting, from trying out previously unknown targets, to figuring out how to better produce the T-cells, to enhancing the resultant immune response cascade, etc etc.