WASHINGTON, Feb. 16 (UPI) -- An experimental T-cell immunotherapy had "extraordinary" results with leukemia patients -- sending most into remission -- but scientists caution that side effects pose serious dangers for patients.
Three studies presented at the annual meeting of the American Association for the Advancement of Science found reprogramming patients' own immune cells to target specific molecules in cancer led to high rates of remission, though more testing is required before the treatment can be used more widely.
Reprogramming immune cells is often a last resort, researchers said, because of the potential for cytokine release syndrome or overloading defense cells. Many patients participating in the small clinical trial developed fever, and two died during treatment.
Scientists say the potential of the therapy for patients who have not been helped by chemotherapy, radiotherapy, or other treatments remains despite the risks involved, and its efficacy in the recent trial shows it could be a powerful treatment for some cancer patients.
"Essentially what this process does is it genetically reprograms the T-cell to seek out and recognize and destroy the patient's tumor cells," Dr. Stanley Riddell, a researcher at the Fred Hutchinson Cancer Research Center, told the BBC. "[The patients] were really at the end of the line in terms of treatment options and yet a single dose of this therapy put more than ninety percent of these patients in complete remission where we can't detect any of these leukemia cells."
Studies conducted at Fred Hutchinson Cancer Research Center, at the San Raffaele Scientific Institute, and at the Technical University of Munich display methods of removing T-cells from patients, altering their targets for specific cancers, and injecting them back into patients.
Ridell called data from the studies "unprecedented" as 94 percent of patients with acute lymphoblastic leukemia had symptoms completely stop, and more than 80 percent of patients with other blood cancers responded to the therapy, with more than half seeing complete remission.
Dr. Chiara Bonini, a hematologist at the San Raffaele Scientific Institute, said further research is needed on the longevity of the treatment. A long-term treatment involving the modified memory of T-cells to automatically attack cancer it was trained for earlier would be ideal, and she told The Guardian she thinks some type of product for wider use is "very close."
"This is really a revolution," Bonini said. "T-cells are a living drug, and in particular they have the potential to persist in our body for our whole lives."