Seattle cancer trial ‘very good news’ for youthfull patients

More than ninety percent of children and youthful adults with acute lymphoblastic leukemia, or ALL, are in remission after treatment as part of a promising Seattle Children’s clinical trial, researchers reported.

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A year ago, Meagan Mullanix was waiting to see whether the experimental therapy would work, whether her own genetically reprogrammed immune-system cells could truly target and ruin the cancer that almost killed her.

Today, the 23-year-old returning college student is cancer-free, with no evidence of the acute lymphoblastic leukemia, or ALL, that very first struck when she was 17, and then came furious back — even after chemotherapy treatments and a bone-marrow transplant.

“I’m feeling fine. I’m coming up on my year on April twenty five and it looks like I’ll make it,” said Mullanix, one of the very first patients enrolled in a Seattle Children’s clinical trial that uses genetically modified T-cells, a form of white blood cell, to target the deadly cancer in patients from toddlers to youthfull adults.

Of twenty two participants in the trial that began in January 2014, twenty have achieved finish remission, according to tests designed to detect minute traces of cancer cells.

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That’s more than ninety percent success in the patients with the most serious prognoses, those with high tumor burdens or who were diagnosed as babies, according to data released Tuesday at the annual meeting of the American Association for Cancer Research (AACR).

“These results are utterly encouraging,” said Dr. Mike Jensen, director of the Ben Towne Center for Childhood Cancer Research at Seattle Children’s Research Institute, who will present the results.

Also encouraged is Dr. Rebecca Gardner, the Seattle Children’s pediatric cancer experienced who is leading the trial of the cutting-edge procedure now performed at a handful of sites nationwide.

In the very first phase, she has focused on the sickest ALL patients, those who have relapsed after chemotherapy treatment or bone-marrow transplant, who typically have just a ten percent to twenty percent chance of survival. But the fresh results have been so promising, the procedure is being considered as a potential front-line treatment.

“This gives us hope that, eventually, we’ll be able to use this therapy in patients who are freshly diagnosed, reducing the need for toxic therapies and bone-marrow transplants,” Gardner said.

The protocol works by removing millions of T-cells from the patient and then using a viral vector to introduce antibodylike proteins called CARs, or chimeric antigen receptors, to the cells. The re-engineered cells are designed to target a protein on the surface of malignant B-cells known as CD19. The modified T-cells are returned to the patient, where they tie to the B-cells, demolishing them — and the cancer.

“It basically tricks the T-cell into killing what you want it to kill,” Gardner said.

A future trial in adults is planned using a cell product candidate known as JCAR017, manufactured by Juno Therapeutics, a biomedical stiff in Seattle.

In Mullanix’s case, it took only ten days for her reprogrammed cells to eliminate the cancer.

“Her T-cells did a fantastic job of growing and expanding,” Gardner said.

In fact, her cells proliferated so strongly that Mullanix developed one of the signature signs that the treatment is taking hold, a so-called “cytokine storm.”

That occurs when the natural chemicals flood from the cells in the immune system as they are activated, causing high fevers, chills and other symptoms.

“Her figure replicated the cells so quickly, it created a firestorm in her brain,” said Sally Mullanix, 56, Meagan’s mother.

Meagan Mullanix’s reaction was so severe that doctors had to shut down her engineered T-cells or risk death. It left her with durable neurological problems that have led to seizures. She takes medication now to control it but could require surgery in the future, said her mom.

Those complications have kept Meagan Mullanix from fully launching back into her life. She’s waiting for the all-clear to drive again, for example, six months after her last seizure. She stays home a lot, making her feel “cooped-up,” and says she can’t wait to head back to a local community college in the fall.

But the youthful woman who’s been grappling with the disease since high school said she’s not complaining.

“I’m cancer-free, so that’s fine,” she said.

The results of the fresh trial are “very good news,” said Dr. Stephen J. Forman, a cancer accomplished and stem-cell transplant specialist at The City of Hope National Medical Center in Duarte, Calif.

Albeit he’s not involved with this trial, he and Jensen have worked closely together, he said, and they’ve mused about whether the treatment could substitute for chemotherapy in children and adults with ALL.

“It simply puts the question out there, is it possible to use this therapy in the front part of therapy?” he said.

For Meagan Mullanix, who suffered five years of harsh therapies, using the protocol as a very first step instead of a last resort for the disease would be ideal.

“That is honestly what I was hoping for when I very first found out about the treatment,” she said. “I wish it were available to everyone.”

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