A living drug, called CAR-T cell therapy, has revolutionized the treatment of blood cancers, achieving thousands of complete remissions of leukemias, lymphomas and myelomas since its first experimental use in 2010. The therapy involves extracting immune cells from the patient, genetically modifying them, and then reintroducing them, now with an enhanced capacity to destroy cancer cells. However, this successful treatment has so far failed against solid tumors, which are the most common kind. A new study released Thursday offers hope. An ultrasensitive version of CAR-T cell therapy has successfully eliminated human pancreatic, ovarian and kidney cancer tumors implanted in laboratory mice.