The results are surprising, the researchers say, because the combination therapy is far more effective than either treatment alone. Gene therapy was moderately effective in the mice, and bone marrow transplants provided no benefit, but together the two treatments created a striking synergy.
“Until now, this disease has been refractory to every therapy that has been thrown at it,” says Doctor Mark Sands of the School of Medicine. “The results are the most hopeful to date, and they open up a new avenue of research to find effective therapies to fight this devastating disease.”
The combination therapy did not cure the disease, the scientists caution, but mice that received both treatments experienced significant, lasting benefits.
Mice that got gene therapy and a bone marrow transplant lived nearly 18.5 months, more than double the lifespan of untreated mice with the disease. Healthy laboratory mice live about 24 months. And for a significant portion of their lives, motor skills in mice that got both therapies were indistinguishable from those in normal, healthy mice.
While bone marrow transplants carry significant risks, especially in children, the researchers say they may be able to combine gene therapy with another treatment to achieve the same results. This same approach potentially could be used to treat other forms of Batten disease.
Batten disease is an inherited genetic disorder that strikes fewer than five of every 100,000 U.S. children but is slightly more common in northern Europe. There are several forms of the disease, diagnosed at different ages, and all are related to the inability of cells to break down and recycle proteins. Infants with Batten disease appear healthy at birth. But within a few short years, the illness takes a heavy toll, leaving children blind, speechless and paralysed. Most die by age 5.
In the new study, the researchers tested various therapies in four groups of newborn mice with infantile Batten disease. One received only gene therapy; another received only bone marrow transplants. A third was treated with gene therapy and bone marrow transplants; and a fourth group received no treatment. As a comparison, the study included healthy mice without the disorder.
The study’s results show no increase in life span for mice receiving bone marrow transplantation alone compared to untreated mice – animals in both groups lived a median of 8.9 months. Mice that got only gene therapy lived 13.5 months, while those that got the combination therapy lived for 18.5 months.
MEDICA.de; Source: Washington University in St. Louis