Biotech Values

[iwfal]

RTRX

With some more thought I would actually up the chances that the RTRX drug actually induces clinical harms to well over 50% - and my guess is that they can see some of them in their short, very small trial (my guess is a GFR spike the wrong direction). Really proteinurea has to one of the worst surrogates for drug benefit in common use in published papers anywhere in medicine. There are very good reasons that the FDA hasn't, to date, routinely allowed it. MDs and paper writers like it because it is quick and easy - but clearly almost always misleading.

The results are now out. See

FSGS: Dual ETAR/AT1R blockade in DUET study, design #KidneyWk pic.twitter.com/x8Xfv4gbzL

— D.Guerrot (@dguerrot) November 19, 2016

And, I was spot on with my prediction above. Eyeballing the graphs it looks like Sparsentan spikes the eGFR the wrong way by about 10%.

As to what this means for approval - as I've noted before, it all depends upon who they have doing the review at the FDA or giving advice to the FDA. The closer they are to being experts in FSGS, the more likely approval based purely on the ph2, and the closer they are to generalists the more likely rejection - because the CKD community has been oddly focused on proteinurea for a long time despite its poor (putting it mildly) predictive capabilities as surrogate endpoint for drug efficacy. Random WAG is about 50% because other than the eGFR problem the other results look reasonably clean. E.g. the edema results look reasonable.

BTW - to repeat something I've explained at least once earlier on this board, the reason that eGFR is more important than proteinurea is that:

a) GFR is the primary determinant for when to go on dialysis. Not proteinurea.

b) GFR is that determinant because proteinurea is a measure of the kidney leaking things the body should be keeping, and GFR is a measure of toxins that the kidney should be removing but cannot. Toxin buildup is generally a lot more catastrophic than protein leakage - and also something that dialysis can address.

BTW2 - In a company presentation after the release of the topline results the slides show this trial as a phase 2. Not a phase 3.