One challenge in using CAR-T immunotherapy to treat solid tumors is delivering the CAR-T cells directly to the tumor. For blood cancers, The Scientist reports, CAR-T is typically administered via infusion into the blood. But though T cells can cross the blood-brain barrier and reach brain tumors, for example, they don't usually arrive in sufficient numbers to kill the tumor. Researchers are working on ways to get the CAR-T cells to persist longer in the body with repeated infusions; they're also working on ways to administer the cells locally, such as into the intrapleural space for lung cancer.
Selecting the proper antigen target is also key. If researchers don't build a CAR-T treatment that hits only cancer cells and spares the healthy cells around them, there can be serious and dangerous side effects. Testing CAR-T therapy on 3D spheroids can help scientists pick the proper antigen targets. A high-throughput system, like the one utilized in the Corning study, could provide additional insight into antigen targets before the clinical stage.
Future research into 3D immunotherapy is critical, and continued use of spheroids can help to overcome present challenges. Each day brings new innovation and hope — and maybe draws us closer to the day when CAR-T becomes synonymous with cure.