Washington

Three clinical researchers are to face restrictions on their work for their part in a gene-therapy trial that led to a teenager's death in 1999. An out-of-court settlement, under which their employers will pay fines of $1 million, was announced on 11 February. It marks the end of a five-year investigation by the US Department of Justice into the death in 1999 of 18-year-old Jesse Gelsinger in the gene-therapy trial.

Under the terms of the settlement, James Wilson, who led the trial at the University of Pennsylvania, is required to undergo retraining in the conduct of trials on human subjects before he can work with them again.

Wilson hasn't worked with human subjects since January 2000 — four months after Gelsinger died in the trial, which used a modified virus to deliver a gene that was intended to produce a liver enzyme that was deficient. According to an investigation by the university, Gelsinger died from an immune reaction to the adenovirus vector. The widely publicized case led to congressional hearings and to tighter rules on the conduct of clinical trials.

The settlement also places restrictions on the work of Wilson's co-investigators in the gene-therapy trial, Steven Raper, also of the University of Pennsylvania, and Mark Batshaw, of the Children's National Medical Center in Washington. The University of Pennsylvania and the Children's National Medical Center will pay fines totalling $1 million.

The justice department alleged that the researchers and their institutions made false statements regarding the safety of the trial to the National Institutes of Health, the Food and Drug Administration, and the institutional review board that oversaw the research.

But the researchers and their institutions state in the settlement that they did nothing wrong, and that their conduct was “at all times lawful and appropriate”.

The terms of the settlement state that a monitor will supervise Wilson's work in humans for three years, and he will be allowed to conduct only one trial at a time. Any of Wilson's animal research that could affect patient safety will also be supervised. If he fulfils the requirements set out in the settlement, Wilson will then be able to conduct unrestricted research in humans in 2010.

In a statement, Wilson said that the settlement would enable him to continue with his laboratory research. But Jesse Gelsinger's father, Paul Gelsinger, says he is disappointed that the settlement did not require Wilson or anyone else to admit responsibility, apologize for their actions, or release documents uncovered by the justice department. “We just want that kind of closure,” he says. “Without that, I'm finding it impossible to forgive these guys.”