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Two New Therapies 'Buy More Quality Time' for Alzheimer's Patients
Two new drugs, one already approved by the FDA, are showing promise for people suffering from Alzheimer's disease. Researchers presented the details at a recent meeting of the American Neurological Association in Seattle.
The drug rivastigmine, which will be marketed by Novartis Pharmaceuticals under the name Exelon, is expected to be on the market by next year. The FDA approved rivastigmine this spring, and it is already being sold in Europe and in some Latin American countries. The drug is "buying more quality time" for people with Alzheimer's disease, George Grossberg, MD, tells WebMD. Grossberg, who is a director of the division of geriatric psychiatry at St. Louis University Medical School, investigated the drug and was on its safety monitoring board.
Grossberg says rivastigmine shows the best benefit for Alzheimer's patients in the "moderate to severe" phase of the disease. It works by inhibiting an enzyme that breaks down a chemical called acetylcholine. Acetylcholine appears to be involved in learning and memory. Memory loss is one of the debilitating effects of Alzheimer's, along with progressively worse confusion and disorientation. Ultimately, the disease, which affects approximately 4 million Americans, can cause death in 5-10 years, according to the Alzheimer's Association.
One study tested rivastigmine on 2,126 patients. Just over two-thirds of them were given the drug, and the remaining patients received a placebo. The effectiveness of the drug was determined over time by how well the patients performed a group of 27 daily tasks such as balancing a checkbook, driving safely, using the telephone and other household implements, and moving about safely while not getting lost.
Grossberg says improvement was significant on 22 of the tasks. Although the drug did not stop the progression of the disease, it was shown to slow an expected decline brought on by the disease. People who cared for the Alzheimer's patients observed an improvement in most of the daily tasks tested, and in fact, by week 26 of the trial, many of the patients showed improvement on all 27 daily tasks.
In contrast, a significant amount of the patients taking the placebo showed a decline in their ability over time to complete the tasks.
Another study presented at the neurological meeting detailed the effect of rivastigmine on 88 patients in a long-term care facility; all of them exhibited symptoms of moderate to severe Alzheimer's. After 12 weeks, nearly half of the patients showed a 30% decline in apathy, agitation, and delusions, which are common symptoms of the disease. Other patients also showed improvement in those areas, to lesser degrees.
In addition, 4 of 17 patients who had been taking tranquilizers stopped taking them, and more than one-third were able to switch to less powerful tranquilizers.
Grossberg tells WebMD that the main side effect of rivastigmine is a mild, brief nausea while dosage is increased. But, rivastigmine hasn't appeared to cause any "significant" interactions with other medications the patient may be taking, like other drugs in its class do. Grossberg says, "I think it's the next step" in Alzheimer's therapy, until the next generation of drugs are developed in about five years.
Also at the neurology meeting, a study of one of those "next-generation" drugs was presented by representatives of the drug company Hoechst Marion Roussel. Propentofylline, as its called, is a neuroprotective drug, meaning it helps "protect" the nerve cells that are often damaged by Alzheimer's.
Matthias Rother, MD, director of new products/neuroscience at Hoechst in Bridgewater, N.J., tells WebMD that propentofylline targets the inflammatory process of the disease, which is brought on by activated immune cells releasing toxic substances. "This product inhibits this process," Rother says. Propentofylline is interrupting the progression of Alzheimer's.
The drug company's multinational trial followed 486 Alzheimer's patients for 72 weeks. The study measured the effects of the drug by using two different systems: one gauged cognitive tasks, and the other relied on a physician's rating of the patient's condition. After one week, patients showed improvement, Rother says.
Even though improvement after one week is not rare in many studies because of the so-called placebo effect, Rother tells WebMD, "what we felt is important [in this study is that] the decline is much slower than if patients received placebo."
The study used a design whereby the patient is first given the drug, then taken off of it. This is used to determine if the drug effect disappears, which can happen with the current generation of drugs. If you take cholinergic agents, the class of drugs rivastigmine belongs to, away, patients look as if they were never treated, Rother says. "With our drug, we treated and took it away, and the patients kept the effect. This supports the idea that it has another effect than the cholinergic drugs."
Patients taking propentofylline improved on both scales of measurement up until 24 weeks. At that point, decline set in, but the decline in ability was significantly less in the patients taking the drugs than those taking a placebo. Nausea and dizziness were side effects.
Rother would not speculate when the drug would enter its final phase of testing.