One local girl’s fight against leukemia could one day change the way many cancer patients are treated.

Emily Whitehead, 7, of Philipsburg, has formed a growing social-network following of more than 15,000 supporters as she’s fought a recurring battle with acute lymphoblastic leukemia, or ALL, the most common form of pediatric cancer.

But, as she gets further along on her road to recovery, Emily’s celebrity may spread worldwide.

After chemotherapy failed and she could not remain in remission long enough to receive a bone-marrow transplant, Emily and her parents, Tom and Kari Whitehead, turned to Children’s Hospital of Philadelphia and researchers at the University of Pennsylvania for help.

With few other options, Emily became the first child have her own T cells— infection-fighting white blood cells in her immune system known as lymphocytes — genetically engineered to recognize and attack the cancer cells in her body.

ALL is cancer of the B cells, which are another type of lymphocyte.

T cells release chemicals called cytokines that have the potential to kill the cancerous B cells, but T cells don’t naturally recognize them as a threat.

In order to make this happen, researchers added a new gene to Emily’s T cells to train them to go after a specific protein, called CD19, that is produced by the B cells.

Although Emily is the first child in an experimental study to receive this type of care, a similar T cell treatment was given to three men in a separate clinical trial last year. That study, published in The New England Journal of Medicine in August, was ranked No. 10 out of the top 100 stories of 2011 by Discover Magazine.

Dr. Stephen Grupp, the pediatric oncologist treating Emily at Children’s Hospital of Philadelphia, could not comment on the study Emily is involved in because the results won’t be published for several months. But he said the results from the first study were encouraging.

“We have this very exciting, initial sign that these cells are going to work the way they have never worked before,” Grupp said. “But is it going to work in a lot of people? ... We just don’t know that.”

While T cells have been genetically engineered before, putting the cells back into a patient and getting them to grow has been the challenge.

“This is the first time we’ve seen the cells in cancer work,” Grupp said. “And maybe that means we can do something we were never able to do before.”

At the time the study was published, two of the adult male patients were in remission. The third patient had to be treated with steroid medication because of complications, Grupp said. Though he wasn’t in remission, he had far fewer leukemia cells then before the treatment, according to the Discover Magazine article.

Emily received her genetically engineered T cell injections between April 17 and 19. On the second day, she sprung a fever.

A little more than a week later, she was gravely ill in the pediatric intensive care unit, facing lung and kidney failure.

On the night of April 24, her doctors gave Emily a 1 in 1,000 chance of survival, Tom Whitehead said, but she pulled through with the help of steroid medications.

Because the steroids had impacted the T cells in the third male patient in the previous study, many feared it would harm Emily’s T cells, but they also survived.

Today, a little more than a month after receiving the T cell injections, all signs point to Emily being cancer-free, and this is big news for more than just the Whitehead family and their team of doctors.

“They told us how oncologists all over the world know what’s going on here and they’re waiting to find out. … They know it’s worked now and it’s going to be a huge story,” Tom Whitehead said.

Because Emily is the first child to receive this treatment, her doctors don’t know what to expect next.

“All we can do is hope that the good response that Emily has had will continue,” Grupp said.

The researchers at Penn gave the Whiteheads a tour Wednesday of the lab where their daughter’s T cells were engineered. During the tour, they revealed that another adult cancer patient has since received the T cell treatment and a second drug, based on Emily’s ordeal.

Tom said that the night Emily almost lost her life, researchers were working around the clock back in the lab to find any piece of information that would help her.

They said “the way everything unfolded there in the lab, we usually don’t do same-day tests for those proteins, but Dr. Grupp said, ‘I need those today,’ and we did it,” Tom said.

Their findings? A particular protein in Emily’s blood was a little high. To counter it, Emily was given an arthritis medication that targets that particular protein, something not normally used to treat cancer patients, Tom said.

Because of Emily’s quick turnaround after receiving the drug and the fact that it couldn’t do any harm, researchers gave the arthritis medication to their next T cell recipient.

“Now this adult has nowhere near the severity of backlash,” Tom said. “The medicine used on Emily made the fourth adult not get sick.”

Tom added that Penn researcher Dr. Bruce Levine — who had been working on this type of treatment since before Emily was born and was present the day she received her first T cell infusion— “shared with us (Wednesday) that this is the highlight of his career.”

No matter what happens, Emily has made her mark on history, and the care her doctors will give future patients.

“(Emily’s doctors) said, ‘You’re on the front lines of cancer fighting, and we can’t tell you what will happen next week,’ ” Tom Whitehead said. But “(Dr. Grupp) said, ‘Now every other family that has to start into this, they can compare it to Emily Whitehead, who is first, and now they have someone to compare it to,’ ” Tom said.

One thing is for sure: “Emily’s an amazing girl,” Grupp said. “I think that from a personal standpoint people ask, ‘Isn’t it hard to be a pediatric oncologist?’ … but when you see a little girl like Emily fight as hard as she did, I am humbled by how strong these kids are. The best part for me is seeing her get better.”

Heather Hottle can be reached at 231-4636.