Gene Therapy Approaches Milestone; Potential To Cure Diseases Caused By Inherited Gene Defect

• Nancy Meredith
• Asbestos Exposure, Cancer, Mesothelioma, Research, Treatments

You can expect to hear a lot more about gene therapy as a treatment for serious diseases in the years head. Gene therapy is still an experimental treatment in the United States, but holds the potential to cure genetic disorders by replacing a defective gene with a corrected copy of the gene. As The New York Times noted, gene therapy neared a milestone this week.

The European Medicine Agency’s Committee for Medicinal Products recommended approval of a gene therapy medicine to treat lipoprotein lipase (LPL), a rare inherited disorder that involves a defective gene, according to a press release posted Friday on its website. Patients with the disorder cannot produce enough of an enzyme that breaks down fat and may experience life-threatening pancreatitis attacks

If the European Medicine Agency follows the committee’s recommendation, as is typical, the medicine Glybera would be the first gene therapy medication approved for authorization in European countries. No gene therapy has been approved so far in the United States.

Jeffrey Ostrove, chief executive of Ceregene, a gene therapy company in San Diego told The New York Times, that pharmaceutical companies have been reluctant to invest in developing gene therapy drugs because there are no approved medicines. Ostrove said that approval of a gene therapy medicine in western Europe has the potential to change the way gene therapy is viewed.

Researchers have been studying the effectiveness of gene therapy in treating various diseases in clinical trials since a breakthrough discovery in 1989 that an abnormality in one gene on a specific chromosome caused the disease cystic fibrosis. That was a huge discovery. It led to the premise that doctors could cure a patient’s disease by identifying an abnormal gene mutation and replacing the defective gene with a corrected copy. The concept isn’t hard to understand, but making it work is complex. The initial applications of gene therapy are likely to involve rare diseases that may be cured by replacing a single defective gene. Lipoprotein lipase is a good example of that.

Researchers are investigating the applications of gene therapy for treatment of cancer including mesothelioma, a cancer of the lining of the lung caused by asbestos exposure. The University of Pennsylvania has an ongoing gene therapy clinical trial for patients who are newly diagnosed with mesothelioma and patients whose cancer has not responded to other treatments. Patients receive a combination of chemotherapy and a new type of gene therapy called immuno-gene therapy that uses a modified common cold virus to trigger the patient’s immune system to destroy cancer cells. Penn doctors have been encouraged by the response of mesothelioma patients receiving the treatment, Dr. Daniel Sterman an associate professor at the University of Pennsylvania said.

Approximately 2,500 to 3,000 people in the United States are diagnosed with mesothelioma each year with symptoms typically appearing 30 to 50 years after asbestos exposure. The disease is incurable, though there are treatments including chemotherapy, radiation and surgery.

Most people diagnosed with mesothelioma are older workers, retired workers or veterans who were exposed to asbestos fibers in the workplace or military service. Microscopic asbestos fibers when inhaled can lodge in the lungs and remain there a lifetime causing inflammation that eventually leads to asbestos related disease.