An experimental cancer treatment leaves two patients 'cured' after 10 years

A team of researchers has announced that two patients who had chronic lymphocytic leukemia (CLL) in 2010 are still cancer-free a decade later after receiving experimental cancer treatment through a clinical trial at the University of Pennsylvania. 

The treatment, known as CAR T-cell therapy, involves removing T-cells, the cells that fight viruses, from a patient's blood, reprogramming them to attack malignant cells, and then infusing the modified cells back to the body to do the job.

The findings of the latest trial are surely encouraging, indicating that the therapy may be helpful in treating some types of cancer in the long run. As research on the treatment progresses, scientists will continue to refine it, validate its efficacy, and hopefully make it available to more patients.

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What is CAR T-cell therapy?

Two of the three patients who received the CAR T-cell therapy in 2010 have remained disease-free since then. These patients were among the earliest to receive CAR T-cell treatment, allowing clinicians to track their cells and condition throughout the last decade. 

The study tells us that this is essentially a "living" drug as it can persist in the body for years, and appears to be capable of mediating complete, long-term remissions. The researchers were able to detect CAR T-cells in the patients' bloodstreams long after their cancers vanished, according to the study published in Nature. 

“Now we can finally say the word ‘cure’ with CAR T cells,” Dr. Carl June, the principal investigator for the trial at the university, told The New York Times. Still, it should be noted that it’s not impossible for a person’s cancer to come back after such a long time and that study group was small. While it may be too soon to know for certain that these patients are cured, these cases are all very encouraging. 

The therapy's lasting effects

The researchers looked at the fate of modified cells to see why the CAR T-cell therapy was so successful. "The surprising thing is that the types of CAR T-cells that actually persisted seemed to be slightly different than what people were anticipating would be the ones that would result in a long-term population," explained David Maloney, the medical director of cellular immunotherapy at the Immunotherapy Integrated Research Center at the Fred Hutchinson Cancer Research Center in Seattle, per PopSci. 

The cells that persisted weren’t the modified T-cells that attack diseased cells. Rather, “helper” T-cells that are usually involved in coordinating the immune response seemed to stick around. Moreover, laboratory tests revealed that these helper CAR T-cells retained their cell-killing abilities.

"We have long realized that there must be differences between CAR T-cells that persist for long periods and those that die within weeks to months from exhaustion," said John E. Levine, a professor of medicine, hematology, and medical oncology and of pediatrics at the Tisch Cancer Institute at Mount Sinai in New York. "This paper now defines some of those differences." 

It's too early to make generalizations based on the research findings; nevertheless, when additional information about the efficacy of CAR T-cell therapy emerges, it could certainly become a more popular and widely available treatment option. Today, CAR T-cell therapy has been approved by the Food and Drug Administration (FDA) for some types of cancers, and only time and further studies will reveal if it will be the norm of treatment for other cancers.