As promised yesterday, here is an excerpt from a New York Times/Tampa Bay Times article about this year’s blockbuster therapy breakthrough at ASH in Atlanta:
In girl’s last hope, her own cells beat back leukemia
Tampa Bay Times – December 10th, 2012
Emma Whitehead is held by her mother, Kari, in Philipsburg, Pa., on Saturday. Last spring, doctors were running out of options to save Emma. She’s now in complete remission. (New York Times)
PHILIPSBURG, Pa. — Emma Whitehead has been bounding around the house lately, practicing somersaults and rugby-style tumbles that make her parents wince.
It is hard to believe, but last spring Emma, then 6, was near death from leukemia. She had relapsed twice after chemotherapy, and doctors had run out of options.
Desperate to save her, her parents sought an experimental treatment at the Children’s Hospital of Philadelphia, one that had never before been tried in a child, or in anyone with the type of leukemia Emma had. The experiment, in April, used a disabled form of the AIDS virus to reprogram Emma’s immune system genetically to kill cancer cells.
The treatment very nearly killed her. But she emerged from it cancer-free, and seven months later is still in complete remission. She is the first child and one of the first humans ever in whom new techniques have achieved a long-sought goal — giving a patient’s own immune system the lasting ability to fight cancer…
Why don’t you read the entire article and then we can discuss it on the backside:
Pretty amazing and hopeful, right? I first learned about this watching one of the nightly news programs during ASH. A lot of “amazing” new cancer therapies have come and gone over the years. But what I like about this one is the immunotherapy targets aren’t too specific. That’s one reason Emma got so sick.
But that’s a good thing! Because thus far, the idea of individualizing a cancer patient’s therapy looks good on paper, but it hasn’t worked so well in real patients.
Why? My understanding is the antibodies that are created that way can and do destroy a lot of cancer cells. But most cancers have more than one type of “clone.” This is what makes my type of bone marrow cancer, multiple myeloma, so hard to treat over time. These clones morph, bob and weave, changing just enough to evade treatment, even if many are destroyed by traditional chemo or targeted immunotherapy, or both.
And/or researchers may miss one or more clones during their individual work-ups. So eventually, the cancer grows strong again–this time built on stronger, drug resistant cells that weren’t targeted by the original therapy. Scary!
Another reason a lot of these “cures” fizzle-out are that clinical studies end-up revealing that they only help a very small subset of patients. Cancer is, in fact, hundreds of different disorders, each with dozens of subsets. Add genetic variables among patients and this is incredibly complicated stuff! Expecting one type of therapy to work across the board may be unrealistic.
But Novartis wouldn’t be investing 20 million dollars if the company didn’t think it might work. And in theory, this type of individualized immunotherapy–using a patient’s own antibodies to destroy their cancer–is the holy grail of cancer research.
Here’s more about how it works:
To perform the treatment, doctors remove millions of the patient’s T-cells — a type of white blood cell — and insert new genes that enable the T-cells to kill cancer cells. The new genes program the T-cells to attack B-cells, a normal part of the immune system that turns malignant in leukemia.
The altered T-cells — called chimeric antigen receptor cells — are then dripped back into the patient’s veins, and if all goes well they multiply like crazy and start destroying the cancer.
The T-cells home in on a protein called CD-19 that is found on the surface of most B-cells, whether they are healthy or malignant.
Sloan-Kettering’s Dr. Michel Sadelain, is an expert in this type of work. I found his quote from the article to be helpful. “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 said, “could potentially be given only once, maybe only once or twice or three times.”
Apparently, active antibodies have been found in other test subject’s bloodstream for years after their initial therapy.
That, ladies and gentlemen, is research shorthand for CURE.
In the meantime, aren’t you excited for Emma and her parents? Awesome!
Feel good and keep smiling! Pat