Transplanted stem cell 'shield' extends brain cancer survival

For the first time, scientists at the Hutchinson Center have transplanted brain cancer patients’ own gene-modified blood stem cells to protect their bone marrow against the toxic side effects of chemotherapy.

Initial results of the ongoing, small clinical trial of three patients with glioblastoma showed that two patients survived longer than predicted if they had not been given the transplants, and a third patient remains alive with no disease progression almost three years after treatment.

“We found that patients were able to tolerate the chemotherapy better and without negative side effects after transplantation of the gene-modified stem cells than patients in previous studies who received the same type of chemotherapy without a transplant of gene-modified stem cells,” Dr. Hans-Peter Kiem said, whose team led the study.

Dr. Hans-Peter Kiem

This results in decreased blood cell counts, increased susceptibility to infections and other side effects. Discontinuing or delaying treatment or reducing the chemotherapy dose is generally required, but that often results in less effective treatment.

As many as 50 percent to 60 percent of glioblastoma patients harbor chemotherapy-resistant tumors, which makes gene-modified stem cell transplant therapy applicable to a large number of these patients.

“This therapy is analogous to firing at both tumor cells and bone marrow cells, but giving the bone marrow cells protective shields while the tumor cells are unshielded,” said Dr. Jennifer Adair, who shares first authorship of the study with Dr. Brian Beard, both members of Kiem’s lab.