Targeted Genetics defends handling of fatal test case

As more details emerged about the recent death of a patient during a clinical trial conducted by Targeted Genetics of Seattle, the company Monday defended its handling of the case.

The biotech firm's shares plunged 6.55 percent Monday to $1.57 after a Washington Post report identified the patient as Jolee Mohr, 36, of central Illinois, and described her death from internal bleeding and organ failure. Her illness began shortly after receiving the second dose of a genetically engineered arthritis therapy in experimental stages.

The report also raised questions about whether Mohr's condition was reported to the authorities in a timely fashion and whether the clinical study was adequately supervised.

Chief Executive H. Stewart Parker said in an interview that the company has always applied "the highest rigor in clinical trials" and that it behaved properly. She declined to elaborate on the patient's illness or the ongoing investigation.

"We've never seen anything like this patient's symptoms" in any related clinical trials, she said. Parker added that she had talked with the patient's family.

She declined to confirm the patient's identity, citing privacy concerns.

The company said it reported the incident to the FDA "within 24 hours" of determining that the patient's illness was possibly related to the drug. A chronology released by the company shows that occurred 18 days after the patient was injected, in the wake of her admission to a hospital.

Staff at the hospital where Mohr was being treated was the first to alert the FDA, Parker confirmed in the interview.

Mohr's death is being investigated by Targeted Genetics and the U.S. Food and Drug Administration, and the company said "it would be premature as well as irresponsible to draw any conclusions prior to the completion of that investigation."

Both Targeted Genetics and the FDA declined to confirm The Post's account of Mohr's fatal illness. Targeted Genetics said "it is unfortunate that the [Post] article seems designed to agitate as opposed to inform," and denied any improper delay in reporting the patient's condition.

Targeted Genetics said the patient received a second dose of the arthritis therapy on July 2. On July 10, the company learned that she and another patient suffered nausea, fever and vomiting. The other patient recovered, but Mohr was hospitalized on July 13. The clinical investigator thought it unlikely that the symptoms of both patients were related to the drug, the company said in a statement.

On July 17, the investigator told the company that Mohr's condition "was deteriorating," but that it was unrelated to the therapy. The next day, Targeted Genetics notified the chairman of the independent data safety-monitoring board that supervised the study, and on July 19 determined that the incident was possibly related to the therapy.

On July 20, the company informed the FDA.

Parker said the symptoms seen in Mohr haven't been detected in other patients participating in the arthritis study or other therapies that rely on adeno-associated viruses — which scientists use as a transport mechanism or "vector" to carry new genes into cells in an effort to fight disease.

In 1999, an 18-year-old died of an immune reaction to a gene-therapy treatment at the University of Pennsylvania.

But the use of adeno-associated viruses — considered too mild to massively trigger the body's defenses — has so far been considered safe in humans and animals.

Therefore, Mohr's unexpected death befuddled scientists in the field, who are closely following the issue.

"I'm not aware anyone can give a high enough dose where the vector can cause any kind of problems in animals," said Dr. Mark Kay, a gene-therapy expert at Stanford University. "That's why I think it's really surprising."

Until Targeted Genetics or the FDA releases a report on "exactly what happened, it's really hard to know," he said.

"It still doesn't tell us the mechanism," said Dr. William Marks, the principal investigator at a gene-therapy study for Parkinson's disease that uses adeno-associated viruses. "We need the details."

Ángel González: 206-515-5644 or agonzalez@seattletimes.com