January 24, 2013
An immune system drug called Gammagard showed initial promise against stemming the decline of Alzheimer’s disease in an early-stage trial in a very small number of patients. Much more testing will be needed, but scientists are cautiously optimistic that the drug, or ones like it, may offer new help in treating Alzheimer’s disease.
Researchers warn that the results will need to be corroborated in a larger number of patients; the drug was tested in only in a handful of patients. But in four patients who were given the drug intravenously over three years, it appeared to stabilize the disease. It’s the first time a drug appears to have helped stop the underlying disease progression, rather than treating specific symptoms.
While symptoms like memory loss and thinking problems did not improve in these patients, they did not get worse, a noteworthy achievement for an Alzheimer’s treatment. Current Alzheimer’s drugs may ease symptoms for a time, but they do nothing to stop the downward progression of disease, and patients inevitably continue to deteriorate.
Gammagard, also known as Kiovig or intravenous immune globulin, is currently approved to treat a variety of immune system disorders, including an unusual nervous system disorder that causes muscle weakness in the limbs. It contains antibodies that target beta-amyloid, a toxic protein that accumulates and forms plaques in the brains of those with Alzheimer’s disease. It is also thought to quell inflammation, which experts increasingly recognize as a factor in Alzheimer’s and other chronic diseases.
By working through the immune system, scientists hope that Gammagard or related drugs may offer a new avenue for treating Alzheimer’s disease. However, vaccines and other immune-system related therapies have shown exciting initial promise but proved too dangerous, or ineffective, in larger follow-up trials.
For the study, researchers at Weill Cornell Medical College in New York gave varying doses of Gammagard to a small number of patients with mild to moderate Alzheimer’s disease. They were given the drug as a shot every two weeks for up to 36 months. Some patients received a placebo drug for comparison.
All four patients getting an intermediate dose of Gammagard showed stabilization of their disease, with no worsening of symptoms. The drug also appeared to be safe in general.
The drug is obtained by filtering the blood of healthy persons to obtain antibodies and other immune system components. It is expensive, costing thousands of dollars a month.
A larger, advanced-stage trial of the drug in hundreds of people with mild to moderate Alzheimer’s is under way. Results from that study are expected early this year.
But experts caution that the history of Alzheimer’s drug development is littered with promising false starts. Another immune system drug that targets beta-amyloid, called bapineuzumab, for instance, showed much promise in mid-stage trials but offered no benefits in larger follow-up studies. Additional studies of that drug and others are under way.
Source: Baxter International.