Margaret McCartney: The “breakthrough” drug that’s not been shown to help in Alzheimer’s diseaseBMJ 2015; 351 doi: https://doi.org/10.1136/bmj.h4064 (Published 24 July 2015) Cite this as: BMJ 2015;351:h4064
- Margaret McCartney, general practitioner, Glasgow
Our airwaves have been saturated, and the column inches heaved with the news: there’s been a breakthrough.
“Landmark drug to stop Alzheimer’s disease has been unveiled . . . Solanezumab has been shown to slow or even halt the illness,” sang the Daily Mail.1
A “very excited” Eric Karran, from the charity Alzheimer’s Research UK, told the BBC that “these findings are hugely significant in that it’s the first data that we’ve had with the drug actually slowing down the course of the disease . . . we could be on the verge of a . . . radical breakthrough for people with Alzheimer’s disease.”2
Channel 4 announced that “something of a breakthrough” has “been shown to produce a marked slowdown in the rate of development of the disease in some sufferers,” with people taking it ending up “30% less affected by Alzheimer’s than those who did not.”3
And the Daily Telegraph said, “In a landmark announcement, pharmaceutical giant Eli Lilly said that solanezumab has been shown to put the brakes on the disease for people with mild symptoms,” which “prevented mental decline by a third” and “could be available within three years.”4
Even the health secretary, Jeremy Hunt, congratulated Lilly on a “massive step forward” (see https://twitter.com/jeremy_hunt/status/624191410116370432).
GPs such as me are the go-to people for patients with Alzheimer’s disease and their families. So it would be good to know this: is solanezumab a cure, and when will it be available?
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.”5
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.6 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?
Cite this as: BMJ 2015;351:h4064
Competing interests: I have read and understood the BMJ policy on declaration of interests and declare the following interests: I’m an NHS GP partner, with income partly dependent on Quality and Outcomes Framework points. I’m a part time undergraduate tutor at the University of Glasgow. I’ve written two books and earn from broadcast and written freelance journalism. I’m an unpaid patron of Healthwatch. I make a monthly donation to Keep Our NHS Public. I’m a member of Medact. I’m occasionally paid for time, travel, and accommodation to give talks or have locum fees paid to allow me to give talks but never for any drug or public relations company. I was elected to the national council of the Royal College of General Practitioners in 2013 and am chair of its standing group on overdiagnosis. I have invested a small amount of money in a social enterprise, Who Made Your Pants?
thebmj.com News: Hopes rise for new Alzheimer’s drug after secondary analysis (BMJ 2015;351:h4048, doi:10.1136/bmj.h4048)
Provenance and peer review: Commissioned; not externally peer reviewed.
Follow Margaret on Twitter, @mgtmccartney