A virus used in a gene therapy experiment likely didn’t cause the death of an Illinois woman suffering from rheumatoid arthritis, although it can’t be completely ruled out, government health advisers said Monday.
Advisers to the National Institutes of Health said that a massive fungal infection is near the top of the list of likely culprits in the death of Jolee Mohr.
Mohr, 36, died at University of Chicago Medical Center on July 24, several weeks after receiving the second injection of trillions of genetically altered viruses at the Arthritis Center in Springfield, Ill., as part of a gene therapy study for rheumatoid arthritis.
Doctors have since struggled to determine how she died, though a massive Histoplasma capsulatum infection appears to be a leading cause. Advisers to the National Institutes of Health met Monday to hear autopsy results and other evidence to determine what role — if any — the injected virus also may have played.
The genetically engineered virus was used as a vector or vehicle to carry a new gene into Mohr’s body, helping it to make a protein that would ease her arthritis pain. Mohr had suffered from arthritis since her 20s.
“We can’t to 100 percent certainty exclude the vector but as was presented, the data would suggest that it’s unlikely to be playing a role,” said Dr. Howard Federoff of Georgetown University Medical Center, chairman of the Recombinant DNA Advisory Committee. Federoff said the fungal infection, called histoplasmosis, was “near the top” of the lists of likely causes for Mohr’s death.
The fungus is commonly found in the Midwest. At the time of her death, Mohr was taking drugs to treat her arthritis that also can suppress her immune system, which would have weakened her body’s ability to fend off an infection.
Too sick for shot?
Mohr also had taken both antiviral and antibiotic drugs in the days before she received the second shot. Panelists questioned whether Mohr should have received that shot, since she appeared already to have been complaining of sickness, including fatigue.
It will take several weeks to complete tests that would show if any of the injected viruses migrated beyond Mohr’s right knee. If none is found, that would make it even less likely the virus played a role.
The experiment’s sponsor, Targeted Genetics Corp. of Seattle, has halted the study and the 126 other patients are being evaluated. A tearful Robb Mohr pleaded with the panel’s members to keep the study on hold until they could figure out what killed his wife.
“There is just no answer to the biggest question I have to the members of the committee: Would my wife still be alive if she didn’t participate in the study? If anyone up there can answer that with any certainty, please don’t put anyone in the American public in my shoes,” he said.
Federoff said the panel could not yet answer that question but that it would seek to bring closure at another meeting set for December, though he cautioned that uncertainties could linger. The panel expects to have the results of blood tests in hand by that time.
“I don’t think the data are in,” said Mohr’s attorney, Alan Milstein, who also represented the family of Jesse Gelsinger. The Arizona teenager’s 1999 death is the only reported fatality definitively linked with a U.S. gene therapy study.
Jolee Mohr fell ill the day after being injected in her right knee. She was initially treated in Springfield, Ill., but transferred to Chicago on July 18. She arrived with a puzzling array of symptoms.
“We were at an initial clinical loss for the cause of all the current problems,” said Dr. Kyle Hogarth, who treated her in the intensive care unit.
She died 10 days later after being removed from life support. A nearly 8-pound pool of blood in her abdomen had crowded out her kidneys and was pressing on her lungs, according to autopsy results — presented after Robb Mohr had left his front-row seat in the auditorium. The source of that bleeding remains unknown but likely hastened her death, doctors said. The autopsy also found signs of fungal infection in her liver, lungs, bone marrow and elsewhere.
Targeted Genetics officials previously have said Mohr might have died of the fungal infection.
The study was designed primarily to assess the safety of the gene therapy treatment. Panel members also discussed ways of preventing study participants from confusing that short-term goal with the longer-term goal of finding a cure for their condition.