Clinical trial of gene therapy a success

by Melanie Evans

Standing in a crowded third-floor room of the University’s Masonic Cancer Center, Iowa native Jim Oliger said his good-byes and thank-yous to staff members assembled around him.
Oliger concluded his participation in the University’s year-long research project on the rare and often fatal genetic disease, Hunter’s Syndrome, which Oliger and six male members of his family carry.
Researchers altered Oliger’s damaged white blood cells using a technique called gene therapy. The corrected cells were then reintroduced into Oliger’s bloodstream by monthly infusions.
The elementary school principal received his final dose of genetically altered and healthy cells Friday.
The University’s successful clinical trial of gene therapy on the hereditary disorder is the first of its kind in the state.
Although not a cure, the results of the trial lay the foundation for further study for the genetic disease, said Dr. Chet Whitley, associate professor of pediatrics and human genetics.
Individuals with Hunter’s Syndrome lack an enzyme needed to break down complex carbohydrates found in connective tissue, such as cartilage.
Without the enzyme, the tissue swells and builds. The resulting skeletal deformation can pinch vital nerves and organs and result in death.
The safe reproduction of healthy cells was one of the triumphs of the trial, Whitley said. Returning the cells to the patient was another, he said.
The patient’s damaged cells are mixed with a “vetcor” — a harmless virus engineered to deliver the genetic code needed to produce the missing enzyme.
The patient’s unhealthy cells are then attacked by the altered “therapeutic” virus.
The resulting new cells are produced and injected into the patient, each carrying the transmitted information for the enzyme.
Given the success of the procedure, the next step for researchers will be to target the stem cell in the bone marrow, Whitley said. By going to the source, the body would be able to produce its own healthy cells.
If successful, the procedure could replace bone marrow transplants, Whitely said.
The transplant success rate for patients with similar metabolic diseases can range from 50 percent to 90 percent depending on conditions, Whitely said.
Transplant-related complications are the cause of the fatalities. Either the body rejects the replacement, or a resulting infection overpowers weak cells, eventually causing death, Whitley said.
The gene-therapy procedure is safer, Whitley said. By returning Oliger’s own genetic material to the blood stream, the procedure eliminates the risk of rejection.
But Whitley said a longer period of more intense study is needed before any therapeutic effects are determined from the current study.
The short-term life span of the mature cells used in the study prohibits the process from becoming an effective permanent solution, he said.
However, University researchers, technologists, nurses and doctors joined Oliger and Whitely on Friday to celebrate the study’s success with cake and non-alcoholic champagne.
Some came to say good-bye to the patient who had become a welcome part of their monthly routine. Others came to meet for the first time the patient who had so radically altered their laboratory practice.
Unique precautions were necessary for the study, said Diane Kadidlo, technical supervisor for the University’s cell therapy laboratory. Kadidlo attended Friday’s reception to meet Oliger.
Research labs were climate-controlled and sterilized for the genetic material, she said. While working with the material, members of her team wore scrubs and hair bonnets.
The lab conducted a few test runs before beginning, said Nancy Bostrom, lead technologist for the laboratory.
Oliger said he will miss all the people with whom he worked.
“The staff here is excellent, I wanted to pat them on the back,” Oliger said.
Although the monthly flight schedule was a challenge, Oliger said he would gladly continue if the laboratory conducted further research.
In his thank-you to the staff, Oliger quoted Mother Theresa, who referred to her lifetime of charitable work as a “drop in the ocean.”
Complementing the staff for their daily efforts to care for patients and cure disease, Oliger likened their work to that of the late nun.
As for his part in the process, “this is my drop in the ocean,” Oliger said.