In breakthrough, patients' immune systems attack cancer cells

University of Pennsylvania doctors have achieved, in a handful of patients, one of the holy grails of cancer research: getting the patient's own immune system to attack cancer cells.
Written by Laura Shin, Contributor

In the quest to find a cure for cancer, one dream of researchers has been to find a way to get the body's own immune system to fight cancer.

On Sunday and Monday, at at a meeting of the American Society of Hematology, some doctors at the University of Pennsylvania reported promising results doing just that.

Even more surprisingly, they reprogrammed the immune systems of their cancer patients using a disabled form of the HIV virus. And, one of their success stories is in a child -- a girl now age 7, whose cancer has been in remission for seven months.

Other cancer centers, such as the National Cancer Institute and Memorial Sloan-Kettering Cancer Center in New York, are also experimenting with this novel treatment.

This research could transform the treatment of leukemia and related blood cancers. It could even work against cancerous tumors. Dr. Carl June, head of the research team at the University of Pennsylvania, said he hoped that this new treatment would eventually replace bone-marrow transplants, which are extremely risky and expensive.

How the treatment works

At age 5, Emma Whitehead was diagnosed with acute lymphoblastic leukemia. Last year, she had relapsed twice after chemotherapy and doctors, having run out of options, tried an experimental treatment that uses a disabled form of HIV to get Emma's own immune system to kill cancer cells.

The treatment first removes millions of the patients own T-cells and then introduce genes that give T-cells the ability to kill cancer cells. (The role of the disabled HIV virus is to carry these new genes into the T-cells.) These new and improved T-cells are then introduced back into the patient's veins, where the hope is that they will then multiply and attack the cancer.

What usually happens right after the new T-cells are introduced is that the patient comes down with high fevers and chills, technically called cytokine-release syndrome, but called "shake and bake" by the doctors. What causes this reaction are natural chemicals pouring out of the cells in the immune system.

In this phase, Emma also had a steep drop in blood pressure, her temperature hit 105 and she ended up on a ventilator, swollen beyond recognition. When everyone had nearly given up hope, the doctors saw that the level of one of her cytokines, interleukin-6, or IL-6, had spiked. As the New York Times reports:

Dr. June knew that a drug could lower IL-6 — his daughter takes it for rheumatoid arthritis. It had never been used for a crisis like Emma’s, but there was little to lose. Her oncologist, Dr. Stephan A. Grupp, ordered the drug. The response, he said, was “amazing.”

Within hours, Emma began to stabilize. She woke up a week later, on May 2, the day she turned 7; the intensive-care staff sang “Happy Birthday.”

Results and implications

So far, three adults suffering from chronic leukemia have been treated and are in complete remission (two of them for more than two years). Four adults improved but are not in full remission, and in two adults the treatment did not work at all. Another child aside from Emma improved but then relapsed.

The researchers believe that patients who did not respond received flawed T-cells.

Though the treatment does not have perfect results, cancer experts not working on this research say that it is promising because it has worked in cases where there were no other options.

Dr. John Wagner, the director of pediatric blood and marrow transplantation at the University of Minnesota, said the results so far were “phenomenal” and that they were “what we’ve all been working and hoping for but not seeing to this extent.”

Another reason these results are generating excitement is that, as Dr. Michel Sadelain, who does similar work at the Sloan-Kettering Institute, put it, “These T-cells are living drugs. With a pill, you take it, it’s eliminated from your body and you have to take it again.” But T-cells, he told The Times, “could potentially be given only once, maybe only once or twice or three times.”

The only drawbacks so far are price and one side effect: Unlike traditional drugs, this treatment requires a new batch of T-cells to be created for each patient, which has a price tag of about $20,000 per patient. While the cost is high, it's still less than the cost of a bone-marrow transplant. The other downside is that the treatment kills off healthy B-cells as well as the cancerous ones, so the patients need regular immune treatments in order to prevent other types of illness.

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via: The New York Times

photo: Healthy T-cell (NIAID/Flickr)

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