Scientists Get OK for Gene-Transfer Trials on Humans
WASHINGTON — The government gave scientists permission Thursday to transfer foreign genes into humans for the first time, approving a test in which bacteria genes will be used to track the effectiveness of a new cancer therapy.
After seven months of review, Dr. James Wyngaarden, director of the National Institutes of Health, gave a team of government researchers the go-ahead to begin the gene-transfer trials.
The Food and Drug Administration approved the plan earlier this week.
Some critics of biotechnology have argued against inserting foreign genes into humans, citing concern that such experiments might go awry and saying researchers should not “play God” with human genetics.
“I would say to those people who raise objections that last year 485,000 Americans died of cancer--one every minute,” said project director Dr. Steven Rosenberg of the National Cancer Institute. “We are trying to develop new treatments to help them and this is important to that effort.
“We have gone through an exhaustive inquiry into the safety of this trial . . . and we have found there is virtually no danger to the general public.”
In October, an institutes advisory panel approved the plan to put new genes in the cells of 10 terminally ill cancer patients. But Wyngaarden sent the project back to the committee after learning that the researchers withheld printed data due to fears that making it public might hurt their chances of publishing articles in scientific journals.
In the new experiment, scientists from the cancer institute and the National Heart, Lung and Blood Institute plan to collect cancer-fighting cells, called tumor-fighting lymphocytes, or TILs, from 10 patients with an advanced stage of a deadly type of skin cancer called melanoma.
Results Unpredictable
The researchers will then “insert marker genes from bacteria into the cells and return the genetically altered cells to the patients from which they were taken,” said institutes spokesman Frank Mahaney.
The tool used to insert the bacteria gene is a mouse leukemia virus that has been “disarmed” so that it cannot cause disease, Mahaney said.
The researchers hope the genetically altered TIL cells will allow them to determine why a promising new form of cancer treatment that uses such cells helps some cancer patients but not others.
In TIL therapy, scientists remove tumors from cancer patients and use a human growth factor, called interleukin-2, to produce large amounts--up to 10 trillion--of the cancer-fighting TIL cells. The cells are then put back into the cancer patient.
Researchers think it should be easy to trace the activity of the genetically altered TIL cells because they are designed to be resistant to an antibiotic that kills normal cells. Blood or tissue samples will be used for those tracking tests.
Rosenberg said he hopes the test will pave the way for therapy in which TIL cells can be genetically altered to produce substances that will improve their efficiency in killing cancer cells.
