Replies to post #123995 on Biotech Values

[genisi]

Derek Lowe:

A secretase inhibitor should just keep new amyloid from being formed and deposited

It is never that simple that something does just this or that. Semagacestat indeed reduces Aß concentrations in the plasma but had little impact on CSF level and BMS-708163 didn't do a lot better on this biomarker. However, changing the blood/CSF/brain equilibrium in Aß concentrations could well affect the removal of amyloid from the brain. This might cause more accumulation in the vasculature due to higher Aß burden and/or inefficient clearance or other unknown mechanism.

I guess that would leave tau as the next batter up.

I'm a tauist myself but so far no meaningful clinical data in this arena and think they are still a few years away.

[mcbio]

It's all very puzzling. With the gamma secretase news, maybe amyloid as a protective response is starting to look more plausible. I guess that would leave tau as the next batter up.

What about the beta secretase inhibitors? What's the latest on them? I know LGND has one in Phase 1 partnered with MRK via their prior acquisition of Pharmacopeia. I take it the point of them is still to try to prevent amyloid production and overall point being that this may not be the best approach.