Small Study Shows Drug May Help Stabilize Alzheimer's
Small Study Shows Drug May Help Stabilize Alzheimerâs
NEW YORK (AP) â For the first time, researchers are reporting that a treatment might help stabilize Alzheimerâs disease for as much as three years, although the evidence is weak and in only four patients.
The drug is Gammagard, made by Baxter International Inc. Doctors say that four patients who have been receiving the highest dose for three years showed no decline on memory and cognition tests. A dozen others on different doses or shorter treatment times did not fare as well.
This study was far too small to prove the treatment works, but a more rigorous one involving 400 patients will give results within a year.
Still, the findings from the small study encouraged doctors at the Alzheimerâs Association International Conference in Vancouver, British Columbia, where they were presented this week.
âItâs tantalizing. If you were to pick out four people with Alzheimerâs disease, the likelihood that they would perform the same on standardized tests three years later is very, very tiny,â said William Thies, the associationâs scientific director.
People typically go from diagnosis to death in about eight years, so to be stable for three years âis a long time,â he said. âWe shouldnât get euphoric and we shouldnât get unreasonable enthusiasm, but this is a positive piece of data.â
The need for an effective treatment is huge: About 35 million people worldwide have dementia, and Alzheimerâs is the most common type. In the United States, about five million have Alzheimerâs. Current medicines such as Aricept and Namenda just temporarily ease symptoms. There is no known cure.
Gammagard is intravenous immune globulin, or IVIG â multiple, natural antibodies culled from donated blood. Half a dozen companies already sell IVIG to treat immune system and blood disorders. These antibodies may help remove amyloid, the sticky plaque that clogs patientsâ brains, sapping memory and ability to think.
On July 17, Dr Norman Relkin, head of a memory disorders program at New York-Presbyterian Hospital/Weill Cornell Medical Center, gave three-year follow-up results on 16 of 24 patients in an earlier study of Gammagard aimed at finding the right dose to use in the larger study. The other eight are no longer being followed, and at least some of them have died.
After the early study ended, some participants were kept on Gammagard and some who had been receiving dummy infusions were switched to Gammagard.
Dr Relkin found:
*As a group, the 11 patients started on various doses of Gammagard fared better than the five started on dummy infusions.
*The five given dummy treatments declined more slowly after they were switched to Gammagard.
*All four participants originally given the highest dose and kept on that dose for three years showed no decline in cognition.
âTo have all four not progress was very eye-opening,â Mr Relkin said. Even a single patient who does not decline over three years is unusual, he said.
âWhen I see that in clinical practice, I start to question whether the person has Alzheimerâs disease,â but all of these study participants were verified by advanced testing to have it, he said.
Other doctors warned against over-optimism on these early results. Many previous drugs looked good until tested in large, definitive studies.
âThatâs the only way we can get data we can really rely on,â said Dr Reisa Sperling, a neurologist at Harvard-affiliated Brigham and Womenâs Hospital in Boston.
Dr Ronald Petersen, director of the Mayo Clinicâs Alzheimerâs Disease Research Center, agreed.
âThe concern with this study is there has been attrition over time,â so the people left in the study are the ones who did well whereas others may have died, he said. These early results âwill just whet our appetitesâ for the bigger studyâs results, he said.
That 400-patient study, headed by Relkin, will end late this year, and results are expected early next year. Treating Alzheimerâs with IVIG would cost $2,000 to $5,000 every two weeks, depending on the patientâs weight, he estimated.
âWe want to make clear that this is not an approved treatment as yet and we are not making any sensational claims,â Mr Relkin said.
Two other experimental Alzheimerâs drugs are in late-stage studies that just ended; results are being analyzed now. They are bapineuzumab by Pfizer Inc and Johnson & Johnsonâs Janssen Alzheimer Immunotherapy unit and solanezumab by Eli Lilly & Co.
Also on July 17, J&J announced that results of two studies testing bapineuzumab will be presented at a neurology conference in Sweden in September. The main result is expected to be announced before then, as soon as it is known.