One of my friends diagnosed with Alzheimer’s recently talked with his counselor about how depressing his cognitive problems are. He is losing hope that new Alzheimer’s drugs will be available in time to help him. Based on media reports, his counselor said she thought he was too pessimistic, and that new treatments were around the corner.
Should patients and families really expect new drugs to be available soon?
The recent wave of failures of Alzheimer’s drugs in trial has heightened the sense that pharmaceutical company investment in this area is risky, reducing funding and causing companies and individuals to consider leaving the field. So showing a little love for researchers in the pharmaceutical industry is a good thing. “We’ve tried to convey that research scientists who come to work every day in America’s biopharmaceutical companies are committed to finding a cure for Alzheimer’s,” says Mr. Belkin.
Of the 98 drugs in the PhRMA report, six are listed as being in Phase III clinical trials. However, three of those drugs had already failed in trials by the time the report was published. The remaining three are anti-amyloid treatments, and one of them (bapineuzumab) is being tested only on people without the APOE4 genetic variation.
If those Phase III trials are successful, and regulatory bodies like the U.S. Food and Drug Administration approve the drugs, they could conceivably be on the market in many countries in less than five years.
Overall, potential treatments in Phase III have an estimated 47% chance of getting to market, which would mean that it’s likely that at least one of these three drugs will be available soon. That estimate is for past decades and all types of drugs, though, and may not be valid for potential Alzheimer’s drugs being tested now. If the amyloid hypothesis is flawed, as some researchers believe, the chances of success for the drugs in Phase III trials could be much lower.
What about the 38 potential treatments listed in the PhRMA report as being in Phase II trials? With an average of 44% of drugs in Phase II transitioning to Phase III trials, and applying the 47% chance of Phase III drugs getting to market, perhaps eight of these 38 potential treatments could eventually be available. But it would certainly be more than five years before any of these drugs now in Phase II were on the market.
So, if past experience with developing all types of drugs were a guide, then Alzheimer’s patients and families might expect to see one new treatment on the market within five years, and a handful within ten years. Developing neurological drugs is more difficult and takes longer than other types of drugs, though. The uncertainty about the causes of Alzheimer’s adds to the difficulty. It’s too pessimistic to predict current trials will end in failure – we need to wait and see what the data says. But I think it’s too optimistic to plan your life around new treatments being available anytime soon.