Replies to post #17509 on NorthWest Biotherapeutics Inc (NWBO)

[Pyrrhonian]

Interesting thought. If it's true (it may not at all be) that ePDs make up a large portion of the roughly 40% with low CD4 counts, and ePDs naturally make up some 25% of those screened, then it's possible this exclusion of ePDs will raise the median PFS of the whole group, despite the omission of psPD LOWERING PFS. So, as flipper pointed out, let's look at IMUC's trial breakdown (from http://investors.imuc.com/secfiling.cfm?filingid=1193125-14-225881&cik=):

-16.7 months OS in control arm (very similar to Avastin's recent trial for newly diagnosed GBM)
-9 months PFS in control arm (similar to Stupp)

It appears patients were enrolled immediately following surgery, which started the clock. Then, following eligibility confirmation, they were either given the ICT-107 vaccine or not.

For the DCVax-L trial, the clock starts 2 months after surgery instead. In either case, all early progressors were omitted from the ICT-107 trial as they are from the DCVax-L trial. Therefore it doesn't appear omitting the ePDs had much effect on OS or PFS, due to any correlation they may have with low CD4s. Also, considering the above, the numbers for the control group of the DCVax trial would probably be:

-14.7 months median OS
-7 months median PFS

Exactly how protocol assumed. Meaning also that the SSR picking up whole group event rates being lower than expected would mean it is most likely the tx group outperforming (another confirmation of sorts).

I'm actually seeing this low CD4 indicator as an issue ONLY when comparing between group rates. If for some freak reason the tx group represented 50% low CD4s and the placebo group only 35%, that would skew results in favor of control, and the real reason would have eluded researchers.

So, it's good that they will be looking for it. It certainly is an important indicator of OS (and so probably PFS... though you know what, I'm not sure of that at all... May not affect PFS much). Regardless, the point is it doesn't appear omitting ePDs (along with psPDs) means a substantial % of those with low CD4 cell counts are also omitted, thereby significantly increasing OS and PFS of the whole group, beyond initial expectations. The recent ICT-107 and Avastin trials for newly diagnosed GBM with the same basic criteria as the DCVax-L trial lays the groundwork for what we'll most likely see here: 9 months PFS for control, or 7 months after randomization.