Modified blood cell shows promise in cancer treatment

By Barry Eitel

SAN FRANCISCO

Cancer patients injected with genetically modified blood cells were found to be in complete remission four years later, researchers said Wednesday.

According to a study published in the journal Science Translational Medicine, modifying white blood cells to attack specific cancers could lead to a groundbreaking approach in cancer treatment. After being injected with modified versions of their own white blood cells in late 2010, three of 14 cancer patients are completely free of the disease without any additional treatment. One patient who was also in complete remission, died from complications after surgery for a skin lesion. Four others experienced at least a partial remission following treatment.

Of the remaining six, two died and four are receiving other treatments.

The patients all suffered from chronic lymphocytic leukemia (CLL), a cancer that attacks the blood and bone marrow. CLL is the most common form of leukemia in American adults and is deemed nearly incurable, with chemotherapy used as method to prolong a patient’s life, not rid the body of the disease. The U.S. government estimates there will be 14,620 new cases of CLL in 2015, and roughly 4,650 will die this year from the cancer.

With an overall response rate of an impressive 57 percent, the new study gives hope to CLL patients.

Essentially, researchers at the University of Pennsylvania separated T cells – the white blood cells that attack foreign particles and infections – from a patient’s blood. The cells go under genetic modification that trains them to attack a protein released by B cells, the type of blood cell affected by CLL. Once injected back into the patient, the T cells destroy all B cells – meaning patients have to live without a crucial part of their immune system, but is still a fate better than death.

“In addition to an extensive capacity for self-replication, the infused T cells are serial killers,” Carl June, MD, leader of the work, said in a statement when the study began. “On average, each infused T cell led to the killing of thousands of tumor cells – and overall, destroyed at least two pounds of tumor in each patient,” he added.