Replies to post #21040 on NorthWest Biotherapeutics Inc (NWBO)

[longusa]

bluesky,

Although there was an improvement in progression-free survival, it could not be considered clinically relevant because of limitations in the methods available to measure the size of brain tumors.

I don't like the sounds of that at all. Does NWBO face a risk of the FDA taking the same position on their clinical trial end point?

The answer is yes, NW faces the risk. However, IMO the issues seen by Avastin are unlikely to hit NW.

Re imaging, NW has excluded psPD patients from the trial (where indeterminate imaging is the issue).

Re efficacy, unlike Avastin, data to date from the PhI's and the 55 patient info arm have shown both a substantial PFS advantage and a substantial OS advantage over SoC. As well, DCVax offers a substantial QoL (quality of life) advantage. Finally, the blinded resizing of the PhIII, which Pyrr has explained in depth, was caused by the overall event rate being far slower than assumed in the original trial design, meaning patients overall in the trial are seeing a much better outcome than SoC (this doesn't prove the PhIII will be successful, but IMO is a good indicator that it is likely).

So for me, my judgment is that those risks are acceptably small.

[Evaluate]

Although there was an improvement in progression-free survival, it could not be considered clinically relevant because of limitations in the methods available to measure the size of brain tumors.

I don't like the sounds of that at all. Does NWBO face a risk of the FDA taking the same position on their clinical trial end point?

Good question. I do not know the answer.
I started looking around a bit at recent articles about this topic. Below are a few links. Looks like some combination of imaging methods might give best results (as opposed to using a single imaging method).
www.ruralneuropractice.com/article.asp?issn=0976-3147;year=2014;volume=5;issue=1;spage=94;epage=98;aulast=Tiwari

www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0099616

www.ismrm.org/14/program_files/EP04.htm

www.appliedradiology.com/articles/the-basics-of-diffusion-and-perfusion-imaging-in-brain-tumors

www.biomedcentral.com/1471-2342/14/26