Nora Situm, the 5-year-old Croatian child seeking an experimental leukemia therapy at Children's Hospital of Philadelphia, has overcome the first obstacle to qualifying for the treatment.

Doctors have collected a big enough supply of her T cells, the immune cells that form the basis of the therapy, said Richard Aplenc, Nora's oncologist.

The update came in a video statement released Friday by the hospital and Nora's parents - her mother, Giana Atanasovska, and father, Ivica Situm.

Nora's arrival at Children's on February 7 was the subject of controversy here and in Croatia because of a misunderstanding over the cost of the treatment.

Croatians raised more than $600,000 to cover those costs - a huge sum for a small country with a limping enonomy - then blasted the hospital on Facebook, mistakenly accusing it of jacking up the price to more than $800,000. Atanasovska later posted an apology, saying she had been confused by information from the hospital.

On Friday, Atanasovska offered thanks "to all the people in Croatia who got us here to give us a chance for our child."

She also praised the hospital, thanking Nora's caretakers for their "kindness." The first thing she saw when she walked into the West Philadelphia medical center, she said, was the slogan, Hope Lives Here.

"It was so right," she said.

The therapy, developed by University of Pennsylvania researchers, involves genetically engineering T cells to recognize and attack B cells, which turn malignant in certain types of leukemia, including Nora's.

Although still very early in clinical use, the therapy has been remarkably effective in the dozen patients for whom researchers have released results.

For Nora, who has exhausted conventional treatment options, the next step will be forcing her T cells to multiply in the lab. If that process is successful, the cells will be modified and given back to her to see if they attack her cancer.

"It's going to take some time," Atanasovska said of the three-month process. "It's very experimental, but it's a chance."

Contact Marie McCullough at 215-854-2720 or