You may have seen the hype. GAME-CHANGING CURE FOR ALZHEIMER: THE NEW DRUG, NEW BREAKTHROUGH. Next Best Thing To Alzheimer’s Cure: Solanezumab May Delay Onset Of Dementia By 30%. Have scientists found a drug to stop Alzheimer’s disease?
I’m going to have to pop your balloon. Someone knowledgeable actually looked at the study.
I searched the internet; there was a conference in the United States. I searched the website and found a press release: it seems that Lilly has funded research. EXPEDITION and EXPEDITION2 are published placebo controlled trials of solanezumab, which did not reach statistical significance on their primary endpoints.5 However, cognitive scores in a subgroup analysis of people with milder symptoms were purported to show benefit.
So, in an extension study (EXPEDITION-EXT), which has given rise to all of this fuss, patients in this subgroup were offered a further trial. Those previously taking placebo crossed over to the active drug, and the groups were compared. The researchers comparing cognitive function noted, “Treatment differences between the early start and delayed start groups . . . remained significant through 52 weeks.”
I asked Lilly what the differences were. The company sent me an interim analysis—“in press” as of 15 July—which seems to have got no attention. It contains graphs that allow comparison of various cognitive instruments over time between the two groups of the extension trial. There’s one that I know: the mini mental status examination, which is scored out of 30. The graph’s axis runs from 0 to –8, and the difference between the two groups never exceeds 1 point.
Two other cognitive scores are ADAS-Cog14 and ADCS-iADL. Never is there a difference of more than 2 between the groups, and they are scored out of 90 and 56. These are tiny differences: they may mean nothing at all for quality of life, and they may have occurred by chance.
This is no breakthrough. How did this paper score such extraordinary publicity?
That’s a really good question Margaret McCartney asks.