Experimental therapy trains immune cells to hunt and kill blood cancers

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    Now to a promising medical story in the continuing fight against cancer. It's about a big change in the world of oncology.

    These days, there's growing interest, better results and more pharmaceutical dollars to develop immunotherapy, or using one's immune system to attack cancer cells. It's been a long road to get to this point. For decades, researchers have tried to find a way to make this kind of treatment work for patients. And now oncologists believe they are turning a corner.

    Special correspondent Jackie Judd has our report about one intriguing approach in Philadelphia.


    This is your first look?

    DR. CARL JUNE, Perelman School of Medicine, University of Pennsylvania: Yes, it is.


    If buildings tell a story, the story here is one of progress. Dr. Carl June leads the team responsible for a promising trial in which the body's immune system is turned into a cancer-fighting weapon.

    He and a once-small group of researchers began work in a closet-sized space, but soon will have two floors of what will be a state-of-the-art building at the University of Pennsylvania.

    And this will be the largest group of people working on immunotherapy in an institution?


    Oh, yes, we think by far it's the largest group in the world.


    Here is why. Since 2010, a group of children and adults suffering from leukemia and running out of treatment options have been in an experimental trial in which their immune system cells were genetically modified to kill cancer. It is an approach other institutions are pursuing as well. The first results at Penn startled even Dr. June.


    The actual truth is our first patients, I got an e-mail from our physician that the leukemia biopsy came back with no more leukemia. My actual response to him was, I don't believe it. So they went and three days later repeated this, and then got the same answer, that there was no leukemia.


    Subsequent results were so convincing, the drug company Novartis entered into a commercial partnership with Penn, including $20 million for the new research center.

    While the clinical trial is limited to a very small group of people, the Food and Drug Administration has agreed to a speedy review of the treatment for wider use.

    Tony DeMarco is patient number 45 in the trial. The now-retired police officer, who lives with his family in Eastern Pennsylvania, was growing weaker as chemotherapy became less and less effective in keeping his leukemia at bay.


    I couldn't function at all. I was in bed for two or three days at a time. You know, I'd wake up, eat, go to the bathroom. And taking a shower was a chore.


    Last May, DeMarco began the new treatment.


    They put you on a machine similar to a dialysis machine, where they will have one line in one arm, and one line in the other arm, and it takes your blood out through the machine, and through a centrifuge.


    From there, T cells, part of the body's immune system, are extracted from the patient's blood and genetically altered to recognize leukemia. The T cells are modified with deactivated HIV, the very same virus that causes AIDS.

    In this case, the HIV is doing good. The so-called hunter cells are then put back in the patient.

    David Porter treats DeMarco and other adults in the trials.

    DR. DAVID PORTER, Perelman School of Medicine, University of Pennsylvania: This virus is very efficient at getting into the T cells and into the immune cells.

    I use an analogy when I explain this to my patients, that a cancer cell has a piece of Velcro stuck on it, but the T cell doesn't have the other piece of Velcro to stick together. We're genetically changing that T cell to put a new piece of Velcro on the outside, so now it can see, and recognize, and stick to the cancer cell, and start killing it.


    Days following DeMarco's transfusion, the Velcro stuck. He began to feel ill, the signal that the modified T cells were waging a war on the cancer cells.

    Did you kind of cheer when you began feeling a little under the weather?


    Oh, yes, we took a selfie, and sent it to the nurses and everything. It says, guess what, I'm sick. And they're like, yes.


    DeMarco's post-therapy symptoms were relatively mild compared to some other patients who suffer through days of raging fevers and pain.

    In 2012, Emily Whitehead became the first child to undergo the experimental treatment at Children's Hospital in Philadelphia, where the pediatric trials are taking place. After the infusion, she was near death from the potent side effects, but rallied and is now cancer-free.

    In December, the research team released updated results of their trial. Of the 39 children enrolled, more than 90 percent responded to the treatment and most were still in remission six months later. Of the 59 adults enrolled, about 55 percent responded. Those who didn't were still fighting the disease or had died.

    Some patients have remained in remission as long as three or four years, demonstrating the durability of the modified cells. Tony DeMarco is less than a year out from his treatment, and a feeling of well-being is returning.


    I'm probably up to about 70 percent power. Now it's — I have a couple bad days a month. Everything else is good.


    The sustained success of treating patients with blood cancer with different forms of leukemia has encouraged doctors here to keep going. They are now investigating whether the same treatment can be equally successful in killing solid tumors.

    One target is glioblastoma, the type of brain cancer that killed Senator Edward Kennedy.

    Dr. Marcela Maus led the research using mice.

    DR. MARCELA MAUS, Perelman School of Medicine, University of Pennsylvania: Here's a mouse that's been treated with the CAR T cells that we're using to target glioblastoma, and we see that most of the tumor is gone. So that makes us feel comfortable thinking that this kind of T cell would actually potentially be effective for brain cancers.


    And the results have been consistent?




    So, recently, three brain cancer patients were treated with the re-engineered T cells.

    Are their tumors shrinking?

    DR. DONALD O'ROURKE, Perelman School of Medicine, University of Pennsylvania: It's the critical question in all of this, where there's so much scientific appeal. There's a lot of pre-clinical data. There's the clinical history with the lymphoma patients. But will it work in the brain? It's too early to tell.


    Unknowns include whether the modified T cells can penetrate a barrier around the brain to get to the tumor, and whether patients can withstand the side effects.


    We have been concerned from the beginning that release of these compounds called cytokines from the T cells would cause a lot of inflammation in the brain. And the brain is a closed structure. And if you have inflammation and swelling, people could get sick.


    I will also ask for the appropriation of an extra $100 million to find a cure for cancer.


    Since then President Richard Nixon declared a war on cancer in 1971, promising developments later disappointed. So the enthusiasm at Penn is tempered by history.


    We need to be careful not to go and raise expectations prematurely, but I think the field now believes that we're — we're on the verge where this can happen, but we also need caution.


    If these early results do hold up, questions would then arise about the cost of treating large numbers of cancer patients with customized medicine that cannot be mass produced. There is also the issue of scalability.


    Every dose of this is individualized to a specific patient. How do you do that for a large number of people, not just in Philadelphia, but around the country, and in fact around the world?


    But, if all goes according to plan, doctors here believe the FDA could approve this therapy for blood cancers next year, which is just when the new center is expected to be up and running.

    For the PBS NewsHour, this is Jackie Judd in Philadelphia.


    You can learn more about this new approach and find a link to the University of Pennsylvania's site on our home page, PBS.org/NewsHour.

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