Experimental Treatment Gives Hope to Leukemia Patients by 'Reprogramming' Cells

— -- An experimental treatment for a deadly form of cancer is bringing new hope for patients with little chance of survival.

Maggie and Andy Oberhofer had discussed hospice options for their ailing baby less than a year ago when the prognosis seemed grim, but today the couple is figuring out how to re-baby proof their home for their 21-month-old daughter, Greta, after she responded to a new leukemia treatment.

Greta has been in different treatments for acute lymphoblastic leukemia for most of her life. Diagnosed when she was 3 months old, Greta has undergone months of chemotherapy, in addition to radiation treatment and a bone marrow transplant from her older sister, Charlotte, her parents said.

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In February of this year, Greta relapsed after the transplant. Greta's doctors in Portland, Oregon, recommended the family look into participating in a small phase 1 medical trial being held at Seattle Children's Hospital aimed at treating children and young adults, who had suffered a relapse of acute lymphoblastic leukemia.

"That weekend we were thinking about it. We didn't want to put her through a whole lot more," Maggie Oberhofer recalled. The family also debated the possibility of hospice care.

The trial took T-cells of patients and "reprogrammed" them by adding recombiant DNA to their DNA so that they were tailored to fight the cancer. Pioneered by the Ben Towne Center for Childhood Cancer Research at the hospital, the treatment genetically modified the immune-response cells so that they develop a receptor that can recognize and bind to cancer cells, according to researchers.

If the cells are able to bind to cancer cells, in theory they can fight the disease similarly to how the immune system might fight off a bacterial or viral infection.

Eventually the couple decided to try the treatment, since it would likely be less painful and invasive than the treatments Greta faced before because it was her own immune cells that would attack the cancer cells. They were warned of potential complications, including brain or spinal inflammation and even the possibility of death.

A week after Greta was given her own reprogrammed cells via an IV drip, she developed a fever, which was actually a sign that the treatment was working, according to her mother. The T-cells had triggered an immune response similar to how a person would develop a cold or flu. Just weeks after the single treatment, Maggie Oberhofer saw a difference in her daughter.

"It was cuckoo. We had to re-child proof [the home]," Oberhofer said of her daughter's quick recovery. "Before this, she was sort of lethargic. ... We took her home that day and she was ripping stuff out of cupboards and throwing stuff."

Within a few months they had returned to Portland, where Greta now gets weekly treatments to bolster her immune system.

Greta is doing much better but not officially cancer-free. Extremely detailed scans have detected a minuscule level of cancer, Oberhofer noted, but Greta's T-cell count also remained high, meaning the immune response could still be fighting the cancer.

"They said you can breathe a big sigh of relief if she maintains a [high] T-cell population" for eight months, said Oberhofer. That watershed moment will come in April.

The results of this medical trial were made public this week at the annual meeting of the American Society of Hematology. Including Greta, 13 patients were given the treatment of "reprogrammed" T-cells and 11 survived, researchers said.

"In this population of patients with relapsed and chemotherapy-resistant leukemia, a treatment with a 20 percent response rate would be considered a success," said Dr. Rebecca Gardner, an oncologist at Seattle Children's Hospital and lead investigator on the immunotherapy trial for acute lymphoblastic leukemia.

Gardner said the findings were relatively new and more research would be needed. The patients that have reacted positively to the treatment have been in recovery between one to eight months and researchers will need to see how they react to the treatment over a longer period of time.

Dr. Hagop Kantarjain, chairman of the Leukemia Department at MD Anderson Hospital in Houston, Texas, said this trial is one of a few exploring this type of treatment and its positive results could mean more treatment options for patients facing little chance of survival.

“This is a very innovative form of therapy,” said Kantarjain. “In general, leukemia experts are very excited about [this] approach."

The Oberhofers said they want to raise awareness of acute lymphoblastic leukemia, particularity how it affects infants. Maggie Oberhofer said her daughter was a rare case where the T-cell therapy worked in an infant.

“There’s work to be done for this specific population for sure,” said Oberhofer. “We’re one of the lucky ones."

ABC News' Neha Gulati contributed to this report.