Reports of success in treating Alzheimer's disease using injections of the arthritis drug Enbrel have sparked hope among Alzheimer's patients and their families - and some concern among physicians.
A recent study reported improvement in cognitive symptoms among 15 Alzheimer's patients who received weekly injections of Enbrel for six months. But doctors not involved in the research say the publicity surrounding it could lead Alzheimer's patients or their family members to believe Enbrel is a proven treatment for the disease when the study actually reflects interesting, but preliminary, research.
The pilot study was published in April by Dr. Edward Tobinick of Institute Research Associates in Los Angeles, along with three co-authors, in the peer-reviewed, electronic medical journal Medscape General Medicine.
The research explored whether Enbrel can reduce the activity of an inflammation-producing substance called tumor necrosis factor alpha in the brains of Alzheimer's patients.
The 15 patients were injected in the back of the neck, above the spine. The study referred to "a sustained and significant improvement in cognition" in both mild and more severe cases.
But Alzheimer's experts who were not involved in the study say it's too early to determine whether the therapy offers real benefits because it was a small pilot study. They said a randomized, controlled trial was needed, in which some patients receive the drug and some do not.
"It's an uncontrolled study; that's important because many studies which look promising in an open study end up not being successful," says Dr. P. Murali Doraiswamy, a Duke University psychiatrist who is on the Alzheimer's Foundation of America's medical advisory board.
The concept behind the study - using a novel route to deliver an anti-inflammatory drug - is intriguing, says Doraiswamy. But previous research using other anti-inflammatory drugs in Alzheimer's patients has failed, he says. The Alzheimer's Foundation of America does not advocate the use of anti-inflammatory drugs because of the lack of evidence that they work.
Moreover, anti-tumor necrosis factor medications, including Enbrel, have been associated with rare but serious side effects, says Dr. George Bartzokis, a neurology professor and director of the clinical core of the Alzheimer's Disease Research Center at the University of California, Los Angeles. Enbrel is linked to infections and symptoms of multiple sclerosis.
Experts also questioned whether the drug could reach the brains of patients. Tobinick says he injected it in the neck for closer proximity to the brain.
Shari Roan writes for the Los Angeles Times.