Leukemia Patients Treated by Gene Therapy. Let's Hope the Cure Doesn't Kill Them This Time.S

On Wednesday scientists announced an exciting new potential cure for leukemia using gene therapy. Yay. Let's hope the test subjects don't get sick and die. Because that's what happened last time.

Gene therapy has had a bumpy 20-year history of seemingly curing patients with various diseases, only to later cause side effects as bad if not worse than the original disease. Jesse Gelsinger, an 18 year-old with a rare liver disease died in 1999 during a gene therapy experiment, halting one of the first human clinical trials for gene therapy. In another experiment, French boys with a rare immune disorder known as "bubble boy disease" seemed to be successfully treated with gene therapy until 2002 when they developed leukemia (ironically, the disease treated in the newest research) as a side effect.

Gene therapy is tricky partly because to make it work in all of the cells in the body, it requires a vehicle to carry and proliferate it. A virus is the most efficient thing scientists have found so far. And even though they try to alter the virus to make it harmless, sometimes it still does damage, which is what led to Gelsinger's death.

That hurdle still hasn't been entirely overcome. The University of Pennsylvania researchers who published their recent findings on Wednesday in the New England Journal of Medicine and Science Translational Medicine used a virus to get the gene therapy into patients' cells in a dish, and then injected the altered cells into the patients.

Still, these latest results are dramatic, so here's hoping this will finally be the gene therapy that works. From the Wall Street Journal:

At day 14, the patient came down with chills, a fever and nausea-"the worse flu they ever had," according to Dr. June. There were also signs of acute kidney injury, and the patient had to be hospitalized. While researchers initially worried that the symptoms were signs of worsening leukemia, it turned out they were just the opposite. The patient's tumor "was blown away" almost all at once, Dr. June said.

[Wall Street Journal, Image: New England Journal of Medicine]