It’s been a while since we heard from TauRx, the company that’s been developing an unusual Alzheimer’s therapy targeting tau protein instead of amyloid. They released interesting Phase II data some time ago, but they’ve been improving their formulation and going into a larger, longer Phase III, which is what anyone working on Alzheimer’s has to be ready to do. (Update: here’s a skeptical take on the Phase II data from back in 2008, which is worth a look under current conditions.)
They reported for the first time on this work yesterday, and. . .well. Unfortunately, it looks to me like they’ve ended up with the same problem as pretty much everyone else who takes a promising Alzheimer’s idea into Phase III: the effect basically disappears. Here’s Adam Feuerstein’s wrapup at TheStreet.com: in 891 patients with mild-to-moderate Alzheimer’s, neither of two doses of the TauRx drug (LTMX) showed efficacy versus the control group by either of two different scales for measuring cognitive decline (the ADAS-cog evaluation or straight brain atrophy measurements). No effect at all.
But here’s the kicker: the company says that about 15% of the patients in the trial were not taking any other Alzheimer’s therapy during the trial, and that subgroup showed significant effects with LTMX treatment. As Feuerstein notes, even the head of TauRx says that he has no explanation for these results, although the company believes that they’re significant. I’m not so sure about that, and here’s Matthew Herper with a lot of good reasons to worry. Subgroup analysis is always tricky, and its history in Alzheimer’s is especially fraught (which is one of the reasons I wonder about Eli Lilly pushing ahead with their antibody after basically flat results in their first Phase III). There are just too many ways to get a false positive readout. TauRx may well press ahead on this basis, and good luck to them, but the odds are very steep that there’s nothing to find.
Most of the press coverage has been about how the drug failed – which is accurate – but there were some exceptions. The New Scientist, the Times of London and some other UK outlets went with “Alzheimer’s breakthrough!” headlines, which is just not true. I’m not really sure why it was just British readers who got this misleading take, but all the examples I’ve seen have been from England and Scotland. The press over there has been overenthusiastic about Alzheimer’s before, though, so maybe it’s just another round of that. It’s not good reporting, and raises hopes that shouldn’t be raised yet. Since the initial rush of enthusiasm for the TauRx approach in general, I’ve had a lot of email from people who have been scouring the web looking for something to help out a loved one with Alzheimer’s. Over and over I’ve had to tell them that no, there’s nothing new from the company yet. Unfortunately, now I’m going to have to tell them that there’s something new, and it’s not good at all.