A new drug could slow the progress of Alzheimer’s disease by as much as 80 per cent, a study has suggested.
However, other researchers have expressed scepticism.
The drug, called LMTX, is the first to target ‘tau tangles’ — clumps of proteins that accumulate and spread in the brains of people with Alzheimer’s. Most previous drugs have targeted beta-amyloid, a different protein whose accumulation is also a marker of the disease.
During trials on 891 patients taking LMTX, participants were given memory tests. An 85 per cent slower decline was observed in patients just taking LMTX over 15 months than those taking a placebo. Brain scans also showed they had lost 38 per cent less brain matter.
However, only 135 people in the trial were exclusively taking LMTX. The drug was not effective in patients taking other dementia medication as well.
Professor Claude Wischik, the drug’s inventor, told the Daily Mail: ‘This is the first glimmer of what a disease-modifying drug looks like in practice. We have really remarkable results. Nobody has come to this point before. It is not just a big clinical effect, it is a hard-edged effect on the rate of brain shrinkage.’
But David Knopman, a professor of neurology at the Mayo Clinic, told Forbes that ‘what ultimately counts is the primary analysis’. Under the terms of the primary analysis the study failed. Only when excluding those patients who took LMTX along with other Alzheimer’s drugs could the trial be deemed a success.
It is easy to be sceptical about media stories of ‘cures’ for serious diseases, as we seem to be constantly bombarded with them. This story shows considerable promise, but there are important drawbacks.
One is the sample size. Many of the results were excluded because the drug did not work when administered with other dementia drugs. This reduces the number of relevant study subjects from 891 to 135, which diminishes the study’s reliability. From a positive standpoint, we have useful extra information about the drug — that it is ineffective in the context of these other drugs. But it doesn’t tell us why it is ineffective, and therefore what else could potentially impact its efficacy.